Anatomical and physiological studies on the growth of the inner ear of the albino rat 1 (1923): Difference between revisions

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A. On the growth of the radial distance between the two  
==A. On the growth of the radial distance between the two spiral ligaments==
spiral ligaments (fig. 3, 1-1, 2-2)  
 
(fig. 3, 1-1, 2-2)  


As we have usually four sections of the ductus cochlearis,  
As we have usually four sections of the ductus cochlearis,  
Line 45: Line 47:
there are two radial distances presented, the first, figure 3, 1-1,  
there are two radial distances presented, the first, figure 3, 1-1,  
connecting the two basal sections of the ductus on opposite  
connecting the two basal sections of the ductus on opposite  
sides, and the second, figure 3, 2-2, connecting the two apical  
sides, and the second, figure 3, 2-2, connecting the two apical sections. These distances measure the radial breadth of the  membranous cochlea and of the modiolus combined at these levels.




{{Wada1923 table1}}


TABLE 1
Data on the albino rats used for the study of the cochlea






AGE
In table 2 (chart 1) are entered the values for the radial distances found between the two spiral ligaments in fourteen age groups, from one to 546 days. As we see, the average value
of the two distances grows rapidly from birth till six days of
age. After that period the value increases gradually till twenty
days, while after twenty days the increase is very slight indeed.
The ratios between 1 and 12, 1 and 20, and 1 and 546 days show
these relations.


{{Wada1923 table2}}


BODY WEIGHT


In table 3 are given the average ratios between two radial
distances between I-II and III-IV at four ages. Here we can also
see a rapid increase in the ratio from one to eight days of age,
while afterwards the ratios rise very gradually. The data in
table 2 show that at nine days the mean diameter of the bony
cochlea as thus measured is approximately 97 per cent of the
value at maturity. The cochlea thus attains nearly its full size
at an early age. Chart 1 illustrates this point.


BOOT LENGTH


{{Wada1923 table3}}


BEX


Chart 1 The radial distance between the spiral ligaments, turns I-II and
III-IV, table 2, figure 3 (/-/) and (-).


SIDE
Radial distance at turns I-II.


Radial distance at turns III-IV.


HEARING
Average radial distance for the two foregoing measurements.


All the charts are plotted on age.


days  
The scale for age changes at 50 days. From to 50 days one interval is
equal to five days. From 50 days on, one interval is equal to twenty-five days.


Unless otherwise stated, the measurements recorded in these charts have
been made on radial-vertical sections.


grams


==B. On the growth of the tympanic wall of the ductus cochlearis==


mm.  
Figures 4 to 12 show the appearance in outline at birth, at
three six, nine (not hearing), nine (hearing), twelve, twenty one
hundred, and 546 days, respectively. These figures have been
drawn from the best corresponding sections at the beginning
of the middle turn of the cochlea, figure 3, turn n, which I have
selected as the type, as did Retzius.  


The fact, demonstrated by many authors, Bottcher ('69),
Retzius ('84), and others, that development progresses from
the basal to the apical turn is confirmed in the albino rat.


In the albino rat the development of the cochlea, and especially of the ductus cochlearis, is somewhat retarded as compared
with man, and the papilla with its elements developed in a great
measure during the first ten days after birth.


As we see in figure 4, the ductus cochlearis in the new-born
rat is very immature. It is remarkable that the space which
lies in adult rats axialward of the papilla spiralis between the
membrana tectoria and the limbus spiralis-sulcus spiralis internus
(fig. 10) is not yet to be seen. Instead of the space, there is the socalled greater epithelial ridge (der grosse Epithelwulst of Bottcher)
figure 4, G. consisting of pseudostratified epithelial cells. These
long and narrow cells lie pressed very closely together with
their large oval nuclei at various heights. The surface of the
prominence sinks slightly in its center, and at the outer end of
the prominence more rapidly, where it passes over into the socalled lesser epithelial ridge fig. 4, L. (der kleine Epithelwulst)
at an obtuse angle.


The latter is, of course, a relatively small prominence, making
up the greater part of the papilla spiralis. The pillar cells of
Corti lie with their upper ends at the most inner part of the
surface of the lesser ridge just in the angle with the greater
ridge. They form two entirely separate rows of cells, the inner
and the outer, but so close together that we cannot detect any
space between them. Only the protoplasm of the inner pillar
cell is more transparent above the nucleus, and on the inward
side there is a thin rod passing from the upper end to the lower part near the base. This transparent area is not the locus of
the future tunnel of Corti, but marks the protoplasmic change
into the pillar, as the transparent substance condenses into the
rod. We can see this change beginning in the basal turn before
it appears in the apical turn of the cochlea. The inner and
outer cells make a triangle with a narrow base, which clings to
the membranea basilaris; they turn somewhat outward. 1


A large oval nucleus lies in the basal part of each cell; that of
the inner pillar cell is very large, about twice as large as that
of the outer, and with its long axis in a radial direction. As
figure 4 shows, the inner corner of the inner pillar cell does not
yet reach to the habenula perforata.


The hair cells, which in the albino rat are in four rows through
all the turns, are separated by the pillar cells into two groups,
the inner containing one and the outer three rows of cells. They
are comparatively well developed at birth (fig. 4). The inner
hair cell belongs to the greater ridge, as Kolliker ('67), Gottstein
(72), Retzius ('84), Held ('09), and others have already affirmed,
and contrary to the assertaion of Bottcher ('69) and others.


It is situated in the most outer part of the declivity of the
greater ridge and slants away from the axis with its round lower
end at about half the height of the greater thickening. It has
a large round nucleus in the base and the small hairlet at the top.
This hair cell is nearly twice as large as the outer hair cells.
The three outer hair cells reach down to the middle of the lesser
ridge, not through it, having no process at their basal end.
They end with their upper parts at the surface of the prominence.
They stand not straight, but turn with their long axis very
slightly inward, i.e., the in direction opposite to the long axis
of the inner hair cells. They are cylindrical in form with a round
nucleus at their base and small hairlet on the top.


1
Below the outer hair cells stand the three rows of Deiters'
cells, which have large oval nuclei. These rest with their wide
bases on the basilar membrane and their pointed ends reach
to the surface of the epithelium. They are retarded in development, and at birth their cell bodies are short and undeveloped,
so that they hardly suggest the adult cells.




5.3
* 1 In the following description of the cochlea, 'outward' means away from the axis 'inward' towards the axis.  




48




d"


Hensen's supporting cells (fig. 10, at maturity) are as yet
undeveloped and nearly uniform in height, their nuclei being
at nearly the same level.


R. L.  
Outward from the Hensen's cells the height of the epithelial
 
cells at maturity rapidly diminishes and passes over to the
cylindrical cells of sulcus spiralis externus. At birth no such
distinction is present. Through all the turns the surface of the
lesser epithelial ridge remains about parallel to the plane of the
membrana basilaris.


The membrana basilaris, which stretches from the labium
tympanicum outward to the crista basilaris of the ligamentum spirale, consists of two layers, an upper, membrana basilaris
propria, and an under, tympanic investing layer (tympanale
Belegschicht : Retzius). The former, of course, is divided into
two portions, an inner, zona arcuata (Deiters) and an outer,
zona pectinata (Todd-Bowman). While the zona arcuata is
thin from the beginning of life, the zona pectinata thickens at
its central part where it contains cells with oblong nuclei. On
passing to the spiral ligament it again becomes thin. In the
young, the under layer is not so regular in structure as in the
adult. The *cells close to the basilaris propria are arranged
vertically.






1
Figs. 4 to 12 Showing the increase in size and morphological changes in
each part of the tympanic wall of ductus cochlearis of the cochlea during
growth, in the radial vertical section albino rat. All the figures have been
uniformly enlarged.


Fig. 4 One day. C, greater epithelial ridge; L, lesser epithelial ridge.


4.2
Fig. 5 Three days.  


Fig. 6 Six days.


47
Figs. 7 to 8 Showing the differences in size and morphological changes in
the tympanic wall of ductus cochlearis between a nine-day-old rat which can
already hear (fig. 8) and one that cannot (fig. 7)


Fig. 9 Twelve days.


o"
Fig. 10 Twenty days. In figure 10 we have drawn all the elements of the
organ.


ABBREVIATIONS


R. L.  
M.T., membraua tectoria a. Corti O.P., outer pillar


L.V., labium vestibulare of crista B.C., basal cells


spiralis D.C., Deiters' cells


S.S.I., sulcus spiralis interims Bo.C., Boettcher's cells


S.I.C., cells of sulcus spiralis interims L.S., ligamentum spirale


3
I.S., inner supporting cells N.F., myelinated fibers of ramus
I.H., inner hair cells acustici


O.H., outer hair cells R.F., radial fibers of ramus basilaris
H.S., Hensen's supporting cells acustici in the tunnel of Corti


8.8
S.E.C., cells of sulcus spiralis externus T., tunnel of Corti


M.B., membrana basilaris B., blood vessels


60
I. P., inner pillar 0., bone


Fig. 1 1 One hundred days.


a"
Fig. 12 546 days.




R.  
On the contrary the cells below them, which vanish in great
part with age, have an irregular arrangement; those near the
endothelial cells of scala tympani having a more radial arrangement. Therefore, this layer is thick, several times the thickness
of the basilaris propria, and the thickness increases towards
the upper turns. The vas spirale is strikingly large at this stage
and lies just under the outer pillar and the Dieters' cells.  


The membrana tectoria, beginning at the inner angle of the
ductus cochlearis, where Reissner's membrane rises, covers the
epithelium of the limbus laminae spiralis and the greater epithelial
ridge, lying close to their surfaces. At the inner part it is thin,
but thickens where the greater ridge begins, and at the outer
part again becomes thin. In the basal turn there is seen as a very
thin strand reaching to Hensen's prominence, but in the apical
turn it reaches hardly to the inner hair cell. Although it gives
rise to several thread-like processes going to the surface of the
papilla, these do not seem to connect with the hairs of the hair
cells, but with the terminal plates of the Dieters' cells.


When we divide the tympanic wall of the ductus cochlearis at
the boundary between the greater and lesser epithelial ridges,
we observe that the inner portion from the inner angle to the
outer end of the greater ridge is far larger than the outer portion,
which, however, is the more important for hearing. This
relation becomes more evident as we pass from the base to the
apex. Moreover, the total radial length of the tympanic wall diminishes at this stage towards the apex, though it is larger
in the beginning of the middle turn than in the middle of the
basal turn. As will be shown later, these relations are entirely
reversed in the adult cochlea. This fact indicates that the
cochlea at this stage is very immature.


In the three-day-old rat the cochlea is much better developed
(fig. 5). The radial breadth of the typmanic wall of the ductus
cochlearis becomes greater in all the turns, especially in the upper
turn; therefore the differences between the radial breadths in
each successive turn are smaller than at the earlier stage. There
is some change as we pass towards the apex in the relation of
the inner and outer portion of the tympanic wall. At the basal
turn and the beginning of the middle turn the radial breadth
of the outer portion increases greatly, but diminishes again
towards the apex. Although the radial breadth of the inner
portion increases through all the turns, the proportion of this
increase becomes greater towards the apex. As the inner portion
is composed of the greater epithelial ridge and of the limbus
laminae spiralis, and as the breadth of the latter diminishes
towards the apex, the increase of the radial breadth of the inner
portion is due to changes in the greater epithelial ridge.


The heights of the greater epithelial ridge, however, diminishes
through the successive turns, becoming less and less from base
to apex. Thus in the cochlea at this age it has a small radial
breadth and vertical height in the basal turn and a larger radial
breadth and height in the upper turns.


3
In all the turns the inner hair cell is inclined outwards and
lies with its surface forming the outermost part of the greater
ridge. The obtuse angle which it helps to make (fig. 5) as a
boundary between the greater and lesser ridge in upper turns,
vanishes in the basal turn where there is no sharp boundary
between the two ridges.


The pillar cells of Corti develop more and more during this
early stage; the radial breadth of their base increases, but as
yet there is no space between them. They incline much more
outwards than in the earlier stage. The protoplasmic change
in the rod progresses, especially in the basal turn, and the head
plate of the cell can be seen distinctly.


7.1


The outer hair cells become higher and wider; they are slightly
inclined inward in the upper turn. On passing towards the
basal turn the inclination inward increases, and in the basal
turn it is most oblique, almost at 45, to the plane of the basilar
membrane. In figure 4 the inclination of these cells is only
slight.


54
Deiters' and Hensen's cells are not well developed; the conditions are as in the former stage.


The plane of the surface of the lesser epithelial ridge is intimately related to the development of the outer hair cells and
Deiters' cells, and as the latter are in an undeveloped condition,
it runs nearly parallel to the plane of the membrana basilaris,
sometimes dipping outward.


o"
The membrana basilaris seems to be much longer; its composition is about the same as that in the one-day rat, only the
thickness is somewhat decreased, owing to the reduction of the
rows of cells in the tympanic layer.


The membrana tectoria grows in breadth and thickness,
covering very closely the inner portion of the tympanic wall
and connects outwards with Deiters' and Hensen's cells by
slender fibrous processes the so-called outer marginal zone.
The hairs of the cells stand between these processes, but have
no connection with them.


R. L.  
The vas spirale does not suffer reduction.  


At six days (fig. 6) the development of the cochlea has proceeded futher. The radial breadth of the tympanic wall has
increased. Thus we find the tympanic wall, especially its inner
portion, increasing towards the apex, chiefly owing to the augmentation of the radial breadth of the greater ridge. In this a
remarkable change is to be seen. In the basal turn the long
slender cells disappear in the inner part of the greater ridge,
and instead of them there are found cylindrical cells with oval
nuclei near their bases.


The height of these cells increases gradually to the level of the
surface of the inner hah- cell; their upper surface is here in contact
with the membrana tectoria. Thus a space appears between
the cylindrical epithelium and the membrane the sulcus spiralis interims which is deep and wide in the basal turn,
becomes gradually shallow and narrow as we pass upward, and
in the middle part of the middle turn is to be seen as a small
and flat space. In the apical turn it is not yet present. The
inner side of this space is made by the labium vestibulare of
the limbus laminae spiralis.


As a result of this change in the greater ridge, the obtuse angle
between the greater and lesser ridge vanishes entirely, and the
two surfaces come to lie in the same place. The inner hair cell
becomes larger and inclines less outward.


It is to be noted that the inner hair cell is supported on both
sides by long slender cells. These have been variously described
by several authors, but first Hans Held ('02) and afterwards
Kolmer ('07) have considered them as supporting cells, reaching
from the surface of the hair cell to the plane of the basilar
membrane. Held has termed the cell which lies outward the
' Phalangenzelle. '


3
I have paid some attention to this cell and the changes in it.
It is long and slender and stands between the inner hair cell
and the inner pillar cell, with the upper end reaching to the
surface, and is attached at its base to the inner corner of the
inner pillar. The oblong oval nucleus lies in its basal portion.
On the inner side of the inner hair cell there is a group of two to
three cells of the same kind. These cells, termed ' Grenzzellen '
by Held, stand near the habenula perforata, reach to the height
of epithelium, and have their bases in intimate relation to the
former.


These are not neuro-epithelial cells nor in intimate relation with
the nerve fibers, but similar to the Deiters' cells which support
the outer hair cells.


8.2
The developing pillar cells become progressively wider at their
bases. The inner pillar cell sends a long foot towards the habenula
perforata and in the basal turn it sometines reaches to it. The
outer pillar cell increases its length very rapidly and extends
its foot outward on the basilar membrane. Thus in the basal
turn the triangle made by the inner and outer pillar cells and
having a short base, in the upper turns changes to an equilateral triangle and stands upright on the basilar membrane. In the
apical turn the inner pillar cell is not yet so long as in the lower,
turns and is still inclined outwards. The head plates and pillars
are fairly prominent, but there is as yet no space between them.  


The outer hair cells have grown and are inclined inward.
Deiters' and Hensen's cells have not yet begun to develop, as
have the other elements of the organ of Corti just described.


56
In the membrana basilaris we see the reduction of cells in
the tympanic covering layer. The vas spirale shows more or
less reduction. The membrana tectoria increases its radial breadth
following the associated structures. The so-called marginal zone
connects with Hensen's cells and the lamina reticularis by
fibrous processes.


Among five nine-day-old rats, as shown later, one responded
to the tests for hearing. As the majority of them gave no reaction, the cochlea of the latter, non-hearing rat, may be taken
as the type for this age. The differences between the cochlea
of the hearing and non-hearing rats will be mentioned later.


9
In rats of this age (fig. 7.) the cochlea is still further advanced.
The sulcus spiralis internus appears through all the coils, and is
deepest and broadest in the basal turn, diminishing in depth
or gradually toward the apex. The cells covering the space are
low and cuboid in the lower turns, but in the apical turn they are
yet relatively high, cylindrical cells.


These cells probably have their origin from the long slender
cells of the greater epithelial ridge, as Bottcher ('69) and others
maintain, although Gottstein (72) and some others think that
they come by the outward migration of the epithelium of the
limbus spiralis, and Retzius ('84) regards this latter view as the
more probable.


R.  
The inner and outer hair cells become large and approach
their mature form. The supporting cells of the inner hair cell
are very evident.  


The pillar cells develop more and more, their radial breadth
increases and the pillars and headplates also become distinct.
Sometimes we see a small space between the inner and outer
pillar cells in the lower turn, but not in the upper. Nuel 's space is not yet to be seen. Deiters' cells become longer, somewhat
in the processus phalangeus but chiefly in the cell body, and the
nuclei move upward. Hensen's cells also increase in height
slightly.


While the membrana tectoria lies close to the surface of the
outer part of the greater ridge in the upper turns of the cochlea,
there arises a small space between them, which is continuous with
the sulcus spiralis internus. The outer marginal zone of the
membrane is still connected with Hensen's supporting cells and
the lamina reticularis. The vas spirale remains as a large vessel.
This is the condition of the nine-day cochlea in a rat which does
not hear.


Although the detailed description of the cochlea of the nineday rat which can hear will be deferred for a time, yet to complete
the series of growth changes, figure 8, representing the cochlea
in such a rat, is inserted here.


In the next stage, twelve days old (fig. 9), the development of
the tympanic wall is much advanced. The cells lining the sulcus
spiralis internus and the-inner supporting cells have nearly their
mature form and arrangement in the basal and middle turns;
only in the apical turn many and slender cells remain close to
the inner hair cell.


6
The outer pillar cell shows a remarkable increase in length so
that it is twice as long as in the former stage, while the growth
of the inner pillar is much less marked.


Therefore the outer pillar is much longer than the inner
through all the turns. From this change in the pillar cells it
results that the nearly equilateral triangle formed by them
becomes unequal and its summit is shifted inward. In all the
turns we can see the tunnel of Corti and also the space of Nuel.
The hair cells develop further and their previous inclinations are
increased.


10.2
Deiters' cells show a very rapid development, especially in
the cell body, which increases many times, the nucleus moving
upwards. The inclination of these cells follows that of the
outer hair cells.  




64
Hensen's supporting cells are also fully developed. Through
the development of Deiters' and Hensen's cells a change is
effected in the course of the lamina reticularis. It runs no longer
parallel to the plane of the membrana basilaris, but dips inward.


Though the membrana basilaris remains nearly stationary in
its breadth, the thickness of the tympanic covering layer is
reduced and the longitudinal nuclei in the zona pectinata diminish
in number.


9
The membrana tectoria reaches in the basal turn to the outermost row of the outer hair cells, but the apical turn only to the
second row. The so-called 'outer marginal zone' connects with
the terminal frame (Schlussrahmen) of the lamina reticularis.


In the next stage, the twenty-day-old rat (fig. 10), the papilla
spiralis and the tissues about it are developed almost completely; therefore, the structural relations of the cochlea accord
nearly with those of the adult cochlea, as generally recognized
in histology.


R. L.  
It is to be noted here that in the basal turn, Bottcher's cells
are to be seen in sulcus spiralis externus* as a cell group situated
on the outer part of the vestibular surface of the membrana
basilaris. This cell group consists of several granular compact
and sharply bounded cells entirely covered by high swollen cells
on all sides. That this cell group belongs to the epithelium of
the sulcus spiralis externus can be easily demonstrated. While
the cells in this group show no particular changes in structure,
the neighboring cells diminish in their height and size towards
the apex, and finally become similar to the former. After twenty
days of age the general features of the cochlea are those of the
adult and do not require general description. The finer differences will be discussed in subsequent chapters.  


Figure 11 shows the relations at 100 days and figure 12 at 546 days.


===1. Membrana tectoria===
As stated above, this membrane is
divided into two zones, an outer and inner, using the outer edge
of the labium vestibulare as the point of division (fig. 1, 7-7').
Each zone was again divided into two equal parts at 6-6'and8-8'.
Thus the sum of the breadths of the two outer parts represents in each instance the breadth of the outer zone, and the sum of
the two inner parts that of the inner zone, while the sum of all
four parts gives the total radial breadth. For the purpose of the
exact measurement of the growth of the membrane, I have,
as noted above, projected the sections at 100 diameters and made
the determinations on the outlines thus obtained.


In table 4 (charts 2 and 3) are given the values for the total
average breadth, as well as for that of each zone, and also the
thickness of the membrane, from 1 to 546 days of age. At the
bottom of each column are given the ratios of the breadth at
1 to 546, 12 to 546, and 20 to 546 days. While the ratio between
1 and 546 days is 1.7, those from 12 to 546 days and 20 to 546
days diminish to about 1:1.0, that is the membrane at twelve
days has attained about its full breadth, and there is only a
very gradual increase in its breadth with advancing age. After
twelve days similar ratios are found for the separate zones as
well.


From 1 to 546 days the ratios for the two zones differ considerably; that for the second zone is 1:1.2 and that for the
first is 1:3.6. This is due to the fact that in the cochlea at birth
the development of the labium vestibulare is incomplete, even
in the basal turn, while at the apex we can very often hardly
see the invasion of the mesenchymal tissue in the inner part of
the greater epithelial ridge.


6
At every stage the outer zone is broader than the inner; the
ratio between them at birth is 1:3.8. This diminishes to 1:1.25
at twelve days, after which age it remains practically constant.
Owing to the form of the membrana tectoria and to its great
sensitiveness to the method of preparation, it is difficult to
obtain good values for its thickness.


Generally speaking, the membrane is thickest about midway
between the outer edge of the labium vestibulare and the inner
boundary of the inner hair cell, and it was here the measurements
given in table 4 were made. As shown in this table, the thickness
increases rather rapidly from birth to twenty days, but after
that period remains approximately constant.


11.0


As we know, the radial breadth of the membrane increases
gradually from the basal to the apical turn. Table 5 (charts 4,
5, and 6) shows how the breadth of the total and of each part
of the membrane changes in successive turns from base to apex
according to age. At birth it is broadest in the beginning of the
middle turn (turn II) decreasing gradually towards the apex.
From three to twenty days the greatest breadth is usually found


62
TABLE 4


Average radial breadth of the membrana tectoria and its thickness in radial-vertical
section. Averages of all four turns (charts 2 and 8)


tf




R. L.
AGE




BODT
WEIGHT




 
BODY
9
LENGTH




9.1
Outer zone
between free
end of membrane and
labium




58
Inner zone
labium
vestibulare
and insertion of membrane




9
Total length
of membrane




R. L.
Ratios
inner and
outer zone




Thickness
membrane




days


9


grams


9.8


mm.


57


M


tf


M


R. L.


M


=fc




12


M


13.0


1


70


5


a 1


48


L.


140


+


37


12


177


11.9


1 3.78


68


12


9


3


R. L.


8


+


56


12


134


14.8


94


72


228


d"


. 1.43


L.


32


+


6


15


11


13.0


63


74


154


0"


105


R.


259


+


1.44


15


32


13.5


9


75


10


9


58


R.


158


+


123


15


281


13.0


1.28


74


27


9


12


R. L.


13


+


60


20


157


30.0


126


96


283


cf


1.25


R. L.


25


+


15


20


13


28.0


75


94


160


c?


124


R. L.


284


+


1.29


25


28


38.4


20


107


29


9


95


R. L.


162


+


129


25


291


34.2


1.26


101


38


9


25


R. L.


36


+


104


50


 
162
60.0




Line 438: Line 826:




9
290




R. L.  
1.27




+
34




Line 450: Line 838:




57.5
59




121
125




9
162




R. L.
131




+
293




100
1.24




145.6
35




176
100




a 1
112




L.
159




+
162




100
132




102.5
294




154
1.23




9
36




R.
150




+
183




100
190




100.5
161




152
131




9
292




R. L.  
1.23




+
32




150
257




153.5
137




184
175




9
163




R.
129




+
292




150
1.26




188.9
38




191
366




d 1
181




R. L.
191




+
162




150
131




198.8
293




192
1.24




<?
35




R.
546




+
255




250
213




133.5
163




178
132




9
295




R. L.  
1.23




+
34




263
Ratios 1 546 days




140.3
1 1.2




171
1 3.6




9
1 1.7




R. L.




+
1 2.8




365
t 12 546 "




205.4
1.0




202
1.0




0"
1.0  




L.




+
1.4




365
20 5 "




170.4
1.0




182
1.0




9
1.0




R. L.




+
0.9




368


in turn III, but after this in turn IV. At the bottom of each
column are given the ratios of the radial breadth in each turn
between the several age limits.


179.0
These show that after twelve days there is but little change
in the radial breadth of the entire membrane in any turn.  


On examining the growth in each zone of the membrane
through the several turns, we find that after three days the outer
zone of the membrane becomes at each age always broader
from base to apex.


196




9
31




R.


u


+




546
200




282.1


150


222




<?
100




R. L.


50


+




546
o




227.1


AGE QAYSH
i i


204




rf
O




R. L.


25


+




50




sections. These distances measure the radial breadth of the


membranous cochlea and of the modiolus combined at these levels.
5O 10O 2OO 3OO 4OO 50O


In table 2 (chart 1) are entered the values for the radial


distances found between the two spiral ligaments in fourteen


TABLE 2  
Chart 2 The radial breadth of membrana tectoria, table 4, figure 1.
Total radial breadth of the membrane.


Radial distance between the two spiral ligaments in radial-vertical section
Radial breadth of outer zone.
(chart 1, figure 3)


*- Radial breadth of inner zone.






25 50 50 10O 2OO 3OO 4OO 5OO


Chart 3 The thickness of membrana tectoria, table 4.




AVERAGE DISTANCE BETWEEN TURNS IN M


32


AGE




TTTT'nWP
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON






ta o


i
< -S






a


I-II
2
S
BS




III-IV


.


I-II plus III-IV




days
n w


it


grams




T^cOTtiCO-'^
-HOOOOOO






o; (


mean




1
o;^ ^-^




5


(N 00


1410




925
OOOOOOOO




1168


co o !o


3




8
rH O




1560


rH O


1025




1S93
>> ^


c3


6




11
1 O I




1650


rH'HCScouv.S "3:uj
W i i
' co


1175




1413
20-546




9


GBOWTH OF THE INNER EAR OF ALBINO RAT


10




1635
33




1225


The values at birth are relatively greater than those at three
days, as noted above, due to the undevelopment of the labium
vestibulare. The inner zone grows in a like manner in breadth,
but not so rapidly as the outer zone, and hence its relative breadth
diminishes gradually from base to apex.


1430
Table 6 shows these relations. While the ratios in the inner
zone decreases from base to apex, those in the outer zone increase.
Thus the ratios in the inner and outer zones according to the
turns go in opposite directions. As stated above, the radial
breadth is generally larger in the outer zone, but this relation
is, in general, reversed in turn I, table 5.


TABLE 6 Condensed
Ratios of the radial breadth of each zone of the membrana tectoria


12




13




1640




1233
Ratios according to turns of the cochlea




1437




15




13




1655




1235
Ratios between inner and




1445




20
BOOT




29
INNER CONE




1645
OUTER ZONE




1250
outer zone




1448
AGE




25
__ fjfi**T




36




1620




1250




1435




50




59
Turns




1615
Turns




1253
Turns




1434




100




112
I-II




1663
I-III




1270
I-IV




1467
I-II




150
I-II I




183
I-IV




1618
I




1290
II
 
 
in
 
 
IV
 
 
days
 
 
grams
 




1454




257




137




1655




1275




1465




366




181




1635




1285


1


1460


5


546


1:0.8


255


1:0.5


1680


1:0.0


1265


1:1.2


1473


1:1.3


Ratios 1 12 days 1 1.2


1:1.4


1 20 " 1.2


1:1.8


1 546 " 1.3


1:2.8




TABLE 3 Condensed
1:4.3  


Ratios of distances between the two spiral ligaments along 1-1 (turns I-II) and
along 2-2 (turns III-IV), figure 3


1:0.0




AGE
8




BODY WEIGHT
11




Ratios between the two distances
:0.9
turns I-II and III-IV




days
:0.9




grams
:0.8




:1.4




1  
:1.8




5
:1.9




. 1:0.66
:0.8




8
:1.2




11
:1.6




:0.72
:2.0  




Line 1,026: Line 1,416:




:0.75
:0.9




213
:0.9
 
 
:0.8
 


:1.4


138


:1.8


:0.77


:2.0




age groups, from one to 546 days. As we see, the average value
:0.8
of the two distances grows rapidly from birth till six days of
 
age. After that period the value increases gradually till twenty
days, while after twenty days the increase is very slight indeed.
The ratios between 1 and 12, 1 and 20, and 1 and 546 days show
these relations.


:1.1


In table 3 are given the average ratios between two radial
distances between I-II and III-IV at four ages. Here we can also
see a rapid increase in the ratio from one to eight days of age,
while afterwards the ratios rise very gradually. The data in
table 2 show that at nine days the mean diameter of the bony
cochlea as thus measured is approximately 97 per cent of the
value at maturity. The cochlea thus attains nearly its full size
at an early age. Chart 1 illustrates this point.


:1.5




:1.9


Chart 1 The radial distance between the spiral ligaments, turns I-II and
III-IV, table 2, figure 3 (/-/) and (-).


Radial distance at turns I-II.
203


Radial distance at turns III-IV.


Average radial distance for the two foregoing measurements.
160


All the charts are plotted on age.


The scale for age changes at 50 days. From to 50 days one interval is
:0.9
equal to five days. From 50 days on, one interval is equal to twenty-five days.  


Unless otherwise stated, the measurements recorded in these charts have
been made on radial-vertical sections.


:0.9




B. On the growth of the tympanic wall of the ductus cochkaris
:0.8


Figures 4 to 12 show the appearance in outline at birth, at
three six, nine (not hearing), nine (hearing), twelve, twenty one
hundred, and 546 days, respectively. These figures have been
drawn from the best corresponding sections at the beginning
of the middle turn of the cochlea, figure 3, turn n, which I have
selected as the type, as did Retzius.


The fact, demonstrated by many authors, Bottcher ('69),
:1.4
Retzius ('84), and others, that development progresses from
the basal to the apical turn is confirmed in the albino rat.  


In the albino rat the development of the cochlea, and especially of the ductus cochlearis, is somewhat retarded as compared
with man, and the papilla with its elements developed in a great
measure during the first ten days after birth.


As we see in figure 4, the ductus cochlearis in the new-born
:1.7
rat is very immature. It is remarkable that the space which
lies in adult rats axialward of the papilla spiralis between the
membrana tectoria and the limbus spiralis-sulcus spiralis internus
(fig. 10) is not yet to be seen. Instead of the space, there is the socalled greater epithelial ridge (der grosse Epithelwulst of Bottcher)
figure 4, G. consisting of pseudostratified epithelial cells. These
long and narrow cells lie pressed very closely together with
their large oval nuclei at various heights. The surface of the
prominence sinks slightly in its center, and at the outer end of
the prominence more rapidly, where it passes over into the socalled lesser epithelial ridge fig. 4, L. (der kleine Epithelwulst)
at an obtuse angle.  


The latter is, of course, a relatively small prominence, making
up the greater part of the papilla spiralis. The pillar cells of
Corti lie with their upper ends at the most inner part of the
surface of the lesser ridge just in the angle with the greater
ridge. They form two entirely separate rows of cells, the inner
and the outer, but so close together that we cannot detect any
space between them. Only the protoplasm of the inner pillar
cell is more transparent above the nucleus, and on the inward
side there is a thin rod passing from the upper end to the lower part near the base. This transparent area is not the locus of
the future tunnel of Corti, but marks the protoplasmic change
into the pillar, as the transparent substance condenses into the
rod. We can see this change beginning in the basal turn before
it appears in the apical turn of the cochlea. The inner and
outer cells make a triangle with a narrow base, which clings to
the membranea basilaris; they turn somewhat outward. 1


A large oval nucleus lies in the basal part of each cell; that of
:2.0
the inner pillar cell is very large, about twice as large as that
of the outer, and with its long axis in a radial direction. As
figure 4 shows, the inner corner of the inner pillar cell does not
yet reach to the habenula perforata.  


The hair cells, which in the albino rat are in four rows through
all the turns, are separated by the pillar cells into two groups,
the inner containing one and the outer three rows of cells. They
are comparatively well developed at birth (fig. 4). The inner
hair cell belongs to the greater ridge, as Kolliker ('67), Gottstein
(72), Retzius ('84), Held ('09), and others have already affirmed,
and contrary to the assertaion of Bottcher ('69) and others.


It is situated in the most outer part of the declivity of the
:0.8
greater ridge and slants away from the axis with its round lower
end at about half the height of the greater thickening. It has
a large round nucleus in the base and the small hairlet at the top.
This hair cell is nearly twice as large as the outer hair cells.
The three outer hair cells reach down to the middle of the lesser
ridge, not through it, having no process at their basal end.
They end with their upper parts at the surface of the prominence.
They stand not straight, but turn with their long axis very
slightly inward, i.e., the in direction opposite to the long axis
of the inner hair cells. They are cylindrical in form with a round
nucleus at their base and small hairlet on the top.  


Below the outer hair cells stand the three rows of Deiters'
cells, which have large oval nuclei. These rest with their wide
bases on the basilar membrane and their pointed ends reach
to the surface of the epithelium. They are retarded in development, and at birth their cell bodies are short and undeveloped,
so that they hardly suggest the adult cells.


:1.1


* 1 In the following description of the cochlea, 'outward' means away from the axis 'inward' towards the axis.


:1.5




:1.8




Hensen's supporting cells (fig. 10, at maturity) are as yet
undeveloped and nearly uniform in height, their nuclei being
at nearly the same level.


Outward from the Hensen's cells the height of the epithelial
In turn I the average ratios are, after eight days, smaller than
cells at maturity rapidly diminishes and passes over to the  
1.0; therefore, the inner zone is wider than the outer in turn I.  
cylindrical cells of sulcus spiralis externus. At birth no such
It increases in all ages from turn II toward the apex.  
distinction is present. Through all the turns the surface of the
lesser epithelial ridge remains about parallel to the plane of the
membrana basilaris.  


The membrana basilaris, which stretches from the labium
In table 7 are given the ratios between each turn of the cochlea.
tympanicum outward to the crista basilaris of the ligamentum
The ratios after nine days of age are practically constant according
to age, but those between turns I and II are always smaller
than the others; the ratios for the two latter being alike. The
ratio at one day is, however, an exception, as stated already.


As the measurements show, the membrana tectoria is at birth
relatively undeveloped; it is thin and immature. After birth
it increases rapidly during the first nine days, a statement which
applies generally to the postnatal growth of the organs of the
albino rat. Thus we get a ratio of the radial breadth 1 :1 .7 between
1 and 546 days, but after twelve days the ratios remain practically 1:1.0. (Table 4.)




Figs. 4 to 12 Showing the increase in size and morphological changes in
each part of the tympanic wall of ductus cochlearis of the cochlea during
growth, in the radial vertical section albino rat. All the figures have been
uniformly enlarged.


Fig. 4 One day. C, greater epithelial ridge; L, lesser epithelial ridge.
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON


Fig. 5 Three days.


Fig. 6 Six days.


Figs. 7 to 8 Showing the differences in size and morphological changes in  
It is not my purpose to describe the fetal development of
the tympanic wall of ductus cochlearis between a nine-day-old rat which can
the membrana tectoria, but it is worth while to consider briefly
already hear (fig. 8) and one that cannot (fig. 7)
the zones which compose the membrane; in other words, the parts
of the tympanic wall from which it originated. There are chiefly


Fig. 9 Twelve days.
TABLE 7


Fig. 10 Twenty days. In figure 10 we have drawn all the elements of the  
Ratios of the radial breadth of the membrana tectoria according to the turns of the  
organ.


ABBREVIATIONS
cochlea


M.T., membraua tectoria a. Corti O.P., outer pillar


L.V., labium vestibulare of crista B.C., basal cells


spiralis D.C., Deiters' cells
AGE


S.S.I., sulcus spiralis interims Bo.C., Boettcher's cells


S.I.C., cells of sulcus spiralis interims L.S., ligamentum spirale
BODY WEIGHT


I.S., inner supporting cells N.F., myelinated fibers of ramus
I.H., inner hair cells acustici


O.H., outer hair cells R.F., radial fibers of ramus basilaris
Ratios according to turn of the cochlea
H.S., Hensen's supporting cells acustici in the tunnel of Corti


S.E.C., cells of sulcus spiralis externus T., tunnel of Corti


M.B., membrana basilaris B., blood vessels
I-II


I. P., inner pillar 0., bone


Fig. 1 1 One hundred days.
I-II I


Fig. 12 546 days.


I-IV




days




GROWTH OF THE INNER EAR OF ALBINO RAT
gms.






21






HS




1




22
5


spirale, consists of two layers, an upper, membrana basilaris
propria, and an under, tympanic investing layer (tympanale
Belegschicht : Retzius). The former, of course, is divided into
two portions, an inner, zona arcuata (Deiters) and an outer,
zona pectinata (Todd-Bowman). While the zona arcuata is
thin from the beginning of life, the zona pectinata thickens at
its central part where it contains cells with oblong nuclei. On
passing to the spiral ligament it again becomes thin. In the
young, the under layer is not so regular in structure as in the
adult. The *cells close to the basilaris propria are arranged
vertically.


On the contrary the cells below them, which vanish in great
1 1.0
part with age, have an irregular arrangement; those near the
endothelial cells of scala tympani having a more radial arrangement. Therefore, this layer is thick, several times the thickness
of the basilaris propria, and the thickness increases towards
the upper turns. The vas spirale is strikingly large at this stage
and lies just under the outer pillar and the Dieters' cells.  


The membrana tectoria, beginning at the inner angle of the
ductus cochlearis, where Reissner's membrane rises, covers the
epithelium of the limbus laminae spiralis and the greater epithelial
ridge, lying close to their surfaces. At the inner part it is thin,
but thickens where the greater ridge begins, and at the outer
part again becomes thin. In the basal turn there is seen as a very
thin strand reaching to Hensen's prominence, but in the apical
turn it reaches hardly to the inner hair cell. Although it gives
rise to several thread-like processes going to the surface of the
papilla, these do not seem to connect with the hairs of the hair
cells, but with the terminal plates of the Dieters' cells.


When we divide the tympanic wall of the ductus cochlearis at
1 1.0
the boundary between the greater and lesser epithelial ridges,
we observe that the inner portion from the inner angle to the
outer end of the greater ridge is far larger than the outer portion,
which, however, is the more important for hearing. This
relation becomes more evident as we pass from the base to the
apex. Moreover, the total radial length of the tympanic wall diminishes at this stage towards the apex, though it is larger
in the beginning of the middle turn than in the middle of the
basal turn. As will be shown later, these relations are entirely
reversed in the adult cochlea. This fact indicates that the
cochlea at this stage is very immature.  


In the three-day-old rat the cochlea is much better developed
(fig. 5). The radial breadth of the typmanic wall of the ductus
cochlearis becomes greater in all the turns, especially in the upper
turn; therefore the differences between the radial breadths in
each successive turn are smaller than at the earlier stage. There
is some change as we pass towards the apex in the relation of
the inner and outer portion of the tympanic wall. At the basal
turn and the beginning of the middle turn the radial breadth
of the outer portion increases greatly, but diminishes again
towards the apex. Although the radial breadth of the inner
portion increases through all the turns, the proportion of this
increase becomes greater towards the apex. As the inner portion
is composed of the greater epithelial ridge and of the limbus
laminae spiralis, and as the breadth of the latter diminishes
towards the apex, the increase of the radial breadth of the inner
portion is due to changes in the greater epithelial ridge.


The heights of the greater epithelial ridge, however, diminishes
1 :0.9
through the successive turns, becoming less and less from base
to apex. Thus in the cochlea at this age it has a small radial
breadth and vertical height in the basal turn and a larger radial
breadth and height in the upper turns.  


In all the turns the inner hair cell is inclined outwards and
lies with its surface forming the outermost part of the greater
ridge. The obtuse angle which it helps to make (fig. 5) as a
boundary between the greater and lesser ridge in upper turns,
vanishes in the basal turn where there is no sharp boundary
between the two ridges.


The pillar cells of Corti develop more and more during this
3
early stage; the radial breadth of their base increases, but as
yet there is no space between them. They incline much more
outwards than in the earlier stage. The protoplasmic change
in the rod progresses, especially in the basal turn, and the head
plate of the cell can be seen distinctly.




The outer hair cells become higher and wider; they are slightly
8
inclined inward in the upper turn. On passing towards the
basal turn the inclination inward increases, and in the basal
turn it is most oblique, almost at 45, to the plane of the basilar
membrane. In figure 4 the inclination of these cells is only
slight.


Deiters' and Hensen's cells are not well developed; the conditions are as in the former stage.


The plane of the surface of the lesser epithelial ridge is intimately related to the development of the outer hair cells and
1.2
Deiters' cells, and as the latter are in an undeveloped condition,
it runs nearly parallel to the plane of the membrana basilaris,
sometimes dipping outward.  


The membrana basilaris seems to be much longer; its composition is about the same as that in the one-day rat, only the
thickness is somewhat decreased, owing to the reduction of the
rows of cells in the tympanic layer.


The membrana tectoria grows in breadth and thickness,
1.2
covering very closely the inner portion of the tympanic wall
and connects outwards with Deiters' and Hensen's cells by
slender fibrous processes the so-called outer marginal zone.
The hairs of the cells stand between these processes, but have
no connection with them.  


The vas spirale does not suffer reduction.


At six days (fig. 6) the development of the cochlea has proceeded futher. The radial breadth of the tympanic wall has
:1.2
increased. Thus we find the tympanic wall, especially its inner
portion, increasing towards the apex, chiefly owing to the augmentation of the radial breadth of the greater ridge. In this a
remarkable change is to be seen. In the basal turn the long
slender cells disappear in the inner part of the greater ridge,
and instead of them there are found cylindrical cells with oval
nuclei near their bases.  


The height of these cells increases gradually to the level of the
surface of the inner hah- cell; their upper surface is here in contact
with the membrana tectoria. Thus a space appears between
the cylindrical epithelium and the membrane the sulcus spiralis interims which is deep and wide in the basal turn,
becomes gradually shallow and narrow as we pass upward, and
in the middle part of the middle turn is to be seen as a small
and flat space. In the apical turn it is not yet present. The
inner side of this space is made by the labium vestibulare of
the limbus laminae spiralis.


As a result of this change in the greater ridge, the obtuse angle
6
between the greater and lesser ridge vanishes entirely, and the
two surfaces come to lie in the same place. The inner hair cell
becomes larger and inclines less outward.


It is to be noted that the inner hair cell is supported on both
sides by long slender cells. These have been variously described
by several authors, but first Hans Held ('02) and afterwards
Kolmer ('07) have considered them as supporting cells, reaching
from the surface of the hair cell to the plane of the basilar
membrane. Held has termed the cell which lies outward the
' Phalangenzelle. '


I have paid some attention to this cell and the changes in it.
11
It is long and slender and stands between the inner hair cell
and the inner pillar cell, with the upper end reaching to the
surface, and is attached at its base to the inner corner of the
inner pillar. The oblong oval nucleus lies in its basal portion.
On the inner side of the inner hair cell there is a group of two to
three cells of the same kind. These cells, termed ' Grenzzellen '
by Held, stand near the habenula perforata, reach to the height
of epithelium, and have their bases in intimate relation to the
former.


These are not neuro-epithelial cells nor in intimate relation with
the nerve fibers, but similar to the Deiters' cells which support
the outer hair cells.


The developing pillar cells become progressively wider at their
1.2
bases. The inner pillar cell sends a long foot towards the habenula
perforata and in the basal turn it sometines reaches to it. The
outer pillar cell increases its length very rapidly and extends
its foot outward on the basilar membrane. Thus in the basal
turn the triangle made by the inner and outer pillar cells and
having a short base, in the upper turns changes to an equilateral triangle and stands upright on the basilar membrane. In the
apical turn the inner pillar cell is not yet so long as in the lower,
turns and is still inclined outwards. The head plates and pillars
are fairly prominent, but there is as yet no space between them.  


The outer hair cells have grown and are inclined inward.
Deiters' and Hensen's cells have not yet begun to develop, as
have the other elements of the organ of Corti just described.


In the membrana basilaris we see the reduction of cells in
1.4
the tympanic covering layer. The vas spirale shows more or
less reduction. The membrana tectoria increases its radial breadth
following the associated structures. The so-called marginal zone
connects with Hensen's cells and the lamina reticularis by
fibrous processes.  


Among five nine-day-old rats, as shown later, one responded
to the tests for hearing. As the majority of them gave no reaction, the cochlea of the latter, non-hearing rat, may be taken
as the type for this age. The differences between the cochlea
of the hearing and non-hearing rats will be mentioned later.


In rats of this age (fig. 7.) the cochlea is still further advanced.
:1.3
The sulcus spiralis internus appears through all the coils, and is
deepest and broadest in the basal turn, diminishing in depth
or gradually toward the apex. The cells covering the space are
low and cuboid in the lower turns, but in the apical turn they are
yet relatively high, cylindrical cells.  


These cells probably have their origin from the long slender
cells of the greater epithelial ridge, as Bottcher ('69) and others
maintain, although Gottstein (72) and some others think that
they come by the outward migration of the epithelium of the
limbus spiralis, and Retzius ('84) regards this latter view as the
more probable.


The inner and outer hair cells become large and approach
9
their mature form. The supporting cells of the inner hair cell
are very evident.


The pillar cells develop more and more, their radial breadth
increases and the pillars and headplates also become distinct.
Sometimes we see a small space between the inner and outer
pillar cells in the lower turn, but not in the upper. Nuel 's space is not yet to be seen. Deiters' cells become longer, somewhat
in the processus phalangeus but chiefly in the cell body, and the
nuclei move upward. Hensen's cells also increase in height
slightly.


While the membrana tectoria lies close to the surface of the
10
outer part of the greater ridge in the upper turns of the cochlea,
there arises a small space between them, which is continuous with
the sulcus spiralis internus. The outer marginal zone of the
membrane is still connected with Hensen's supporting cells and
the lamina reticularis. The vas spirale remains as a large vessel.
This is the condition of the nine-day cochlea in a rat which does
not hear.


Although the detailed description of the cochlea of the nineday rat which can hear will be deferred for a time, yet to complete
the series of growth changes, figure 8, representing the cochlea
in such a rat, is inserted here.


In the next stage, twelve days old (fig. 9), the development of
1.1
the tympanic wall is much advanced. The cells lining the sulcus
spiralis internus and the-inner supporting cells have nearly their
mature form and arrangement in the basal and middle turns;
only in the apical turn many and slender cells remain close to
the inner hair cell.  


The outer pillar cell shows a remarkable increase in length so
that it is twice as long as in the former stage, while the growth
of the inner pillar is much less marked.


Therefore the outer pillar is much longer than the inner
1.3
through all the turns. From this change in the pillar cells it
results that the nearly equilateral triangle formed by them
becomes unequal and its summit is shifted inward. In all the
turns we can see the tunnel of Corti and also the space of Nuel.
The hair cells develop further and their previous inclinations are
increased.  


Deiters' cells show a very rapid development, especially in
the cell body, which increases many times, the nucleus moving
upwards. The inclination of these cells follows that of the
outer hair cells.


:1.3


Hensen's supporting cells are also fully developed. Through
the development of Deiters' and Hensen's cells a change is
effected in the course of the lamina reticularis. It runs no longer
parallel to the plane of the membrana basilaris, but dips inward.


Though the membrana basilaris remains nearly stationary in
12
its breadth, the thickness of the tympanic covering layer is
reduced and the longitudinal nuclei in the zona pectinata diminish
in number.


The membrana tectoria reaches in the basal turn to the outermost row of the outer hair cells, but the apical turn only to the
second row. The so-called 'outer marginal zone' connects with
the terminal frame (Schlussrahmen) of the lamina reticularis.


In the next stage, the twenty-day-old rat (fig. 10), the papilla
13
spiralis and the tissues about it are developed almost completely; therefore, the structural relations of the cochlea accord
nearly with those of the adult cochlea, as generally recognized
in histology.


It is to be noted here that in the basal turn, Bottcher's cells
are to be seen in sulcus spiralis externus* as a cell group situated
on the outer part of the vestibular surface of the membrana
basilaris. This cell group consists of several granular compact
and sharply bounded cells entirely covered by high swollen cells
on all sides. That this cell group belongs to the epithelium of
the sulcus spiralis externus can be easily demonstrated. While
the cells in this group show no particular changes in structure,
the neighboring cells diminish in their height and size towards
the apex, and finally become similar to the former. After twenty
days of age the general features of the cochlea are those of the
adult and do not require general description. The finer differences will be discussed in subsequent chapters.


Figure 11 shows the relations at 100 days and figure 12 at
1.1
546 days.  


1. Membrana tectoria. As stated above, this membrane is
divided into two zones, an outer and inner, using the outer edge
of the labium vestibulare as the point of division (fig. 1, 7-7').
Each zone was again divided into two equal parts at 6-6'and8-8'.
Thus the sum of the breadths of the two outer parts represents in each instance the breadth of the outer zone, and the sum of
the two inner parts that of the inner zone, while the sum of all
four parts gives the total radial breadth. For the purpose of the
exact measurement of the growth of the membrane, I have,
as noted above, projected the sections at 100 diameters and made
the determinations on the outlines thus obtained.


In table 4 (charts 2 and 3) are given the values for the total
1.3
average breadth, as well as for that of each zone, and also the
thickness of the membrane, from 1 to 546 days of age. At the
bottom of each column are given the ratios of the breadth at
1 to 546, 12 to 546, and 20 to 546 days. While the ratio between
1 and 546 days is 1.7, those from 12 to 546 days and 20 to 546
days diminish to about 1:1.0, that is the membrane at twelve
days has attained about its full breadth, and there is only a
very gradual increase in its breadth with advancing age. After
twelve days similar ratios are found for the separate zones as
well.  


From 1 to 546 days the ratios for the two zones differ considerably; that for the second zone is 1:1.2 and that for the
first is 1:3.6. This is due to the fact that in the cochlea at birth
the development of the labium vestibulare is incomplete, even
in the basal turn, while at the apex we can very often hardly
see the invasion of the mesenchymal tissue in the inner part of
the greater epithelial ridge.


At every stage the outer zone is broader than the inner; the
:1.3
ratio between them at birth is 1:3.8. This diminishes to 1:1.25
at twelve days, after which age it remains practically constant.
Owing to the form of the membrana tectoria and to its great
sensitiveness to the method of preparation, it is difficult to
obtain good values for its thickness.


Generally speaking, the membrane is thickest about midway
between the outer edge of the labium vestibulare and the inner
boundary of the inner hair cell, and it was here the measurements
given in table 4 were made. As shown in this table, the thickness
increases rather rapidly from birth to twenty days, but after
that period remains approximately constant.


15


As we know, the radial breadth of the membrane increases
gradually from the basal to the apical turn. Table 5 (charts 4,
5, and 6) shows how the breadth of the total and of each part
of the membrane changes in successive turns from base to apex
according to age. At birth it is broadest in the beginning of the
middle turn (turn II) decreasing gradually towards the apex.
From three to twenty days the greatest breadth is usually found


TABLE 4
13


Average radial breadth of the membrana tectoria and its thickness in radial-vertical
section. Averages of all four turns (charts 2 and 8)


1.1




AGE
1.3




BODT
:1.3
WEIGHT




BODY
20
LENGTH




Outer zone
29
between free
end of membrane and
labium




Inner zone
1.1
labium
vestibulare
and insertion of membrane




Total length
1.3
of membrane




Ratios
:1.3
inner and
outer zone




Thickness
25
membrane




days
36




grams
1.1




mm.  
1.3




M
:1.4




M
50




M
59




1.1




M
1.3




1  
: 1.3




5
100




48
112




140
1.1




37
1.3




177
:1.4




1 3.78
150




12
183




3
1.1




8
1.3




56
: 1.3




134
257




94
137




228
1.1




. 1.43
1.3




32
:1.3




6
366




11
181




63
1.1




154
1.3




105
:1.3




259
546




1.44
255




32
1.1




9
1.3




10
:1.3




58


Chart 4 The total radial breadth of membrana tectoria arranged according
to the turns of the cochlea, table 5.


158
About middle part of the basal turn (I).


About the beginning of the middle turn (II).


123
About the middle part of the middle turn (III).


About the beginning of the apical turn (IV). 2


281
Chart 5 The radial breadth of the inner zone of the membrana tectoria,


according to the turns of the cochlea, table 5.


1.28
Chart 6 The radial breadth of the outer zone of the membrana tectoria,


according to the turns of the cochlea, table 5.


27
* In most cases when the values which have been determined are analyzed
according to the turns of the cochlea, it is found that they increase with later
growth from the basal (I) to the apical (IV) turn and in the order just given in
chart 4. Owing to this uniformity of behavior, some thirteen charts showing
the several values according to turn have been omitted, since the graph given
by the average value is sufficiently informing in each instance.


In the case of those charts which have been retained, and in which the
measurements are according to the turns of the cochlea, the respective turns
I-IV are recorded by characteristic lines similar to those used for them in
chart 4, and in these cases the further designations of the turns are omitted.


12




13
350




60


300


157




126
I




283


ISO


1.25




25
G.E DAYSH




15




13




75


25 5O


160




124
50 1OO 2OO 30O 400 500


Chart 4


284




1.29
150




28


1OO


20




29
50




95




162




129


AGE


291




1.26
25 50 50 1OO 200 300 4OO 500


Charts


38




25
180




36


100


104




162
DAYS




128
25 50 5Q 1OO 2OO 3OO 4OO 5OO


Chart 6


290




1.27
36


two views about this. While a few authors, Kolliker ('67),
Hensen ('63), and recently Hardesty ('08, '15), and others hold
that only the greater epithelial ridge takes part in the formation
of the membrane, most investigators (for example, Bottcher,
'69; Retzius, '84; Rickenbacher, '01; Held, '09; Van der Stricht,
'18) consider that it originates from both the greater and lesser
epithelial ridge. My figure 5, supports the latter view; that is,
while the main part is developed from the greater ridge, the
outer narrow marginal part is secreted from the lesser ridge.


34
The figure in Quain's Anatomy by Schafer ('09) (vol. 3, part
2, p. 332, llth ed.,) is from the earlier paper of Hardesty and
shows the membrane in the pig as arising from the greater
epithelial ridge only.


Hardesty has corrected this figure in his paper published in
1915. Thus in the very early stage after birth in these forms
we have three zones, an inner, an outer, and a marginal zone.
With age, however, this marginal zone becomes, as Held ('09)
and others agree, gradually smaller and smaller, and finally
it is difficult to differentiate it from the outer zone. Thus for
convenience in measurements I have treated the membrane as
consisting of two zones only.


50
Comparing the breadth of the inner and outer zones, it is
evident that the outer is always the broader. The ratio is
(table 4) at birth 1 : 3.78, at three days 1 : 1.43, and then gradually
diminishes to 1:1.23 with age.


Now if we examine the ratios of the total breadth of the
membrane according to the turns of the cochlea, we find after
six days that the ratio generally increases from base to apex,
and that these ratios remain nearly constant after nine days
of age, as shown in table 7.


59
Thus the ratio between turns I and II is 1:1.1; between turns
I and III, 1:1.3; between turns I and IV, 1:1.3. The breadth
of the membrane increases, -therefore, in the albino rat gradually
from the base to the middle part of the middle turn; from this
point it does not increase to the apex.


Since the breadth at the tip of the apex diminishes greatly,
as is generally recognized, Hardesty ('08) found in the pig the
following ratios (table 8):


125




162
GROWTH OF THE INNER EAR OF ALBINO RAT




131


37


293




1.24
Comparing these ratios obtained by Hardesty in the pig with
mine, there appear to be large differences between them. The
reason for these I will discuss later.  


When we consider the breadth in each part of the membrane
according to the turn, we find that the increase of the breadth
of the membrane in each turn is due to the development of the
outer zone. The inner zone, which is adherent to the labium
vestibulare, does not increase in the rat as Hardesty ('08/15)
found to be the case for the pig, but on the contrary decreases
from base to apex a relation found by Retzius ('84) in the rabbit,
cat, and man and confirmed by Rickenbacker ('01) in the guineapig. On the contrary, the outer zone increases in breadth from


35
TABLE 8
Ratios of the breadth of the membrana tectoria according to turn of cochlea (Hardesty)




100


Kind of animal


112


Preparation
method


159


Ratios between
breadth in 7 and
5 half turn


162


Ratios between
7 and 3 half turn


132


Ratios between
7 and 1 half turn


294


Pigs two weeks
of age


1.23


Membrane
teased out
Membrane


36


1 : 1.4


150


1 :1.7


183


1 :2.5


190




161


teased out


131


1 :1.8


292


1 :2.5


1.23


1 :2.7


32


Adult


257


Membrane in


137




175




163




129




292


section


1.26


1 : 1.6


38


1 :2.1


366


1 :1.8


181




191
base to apex, and in each stage the ratios between the successive
turns are nearly the same. These ratios between successive
turns, however, show rather large differences according to the
different authors.


My results (table 5) show that the outer zone in the albino rat
is nearly two times wider at the apex than at the base. This
agrees with what von Ebner ('02) finds in the human cochlea.


162
When we consider the thickness of the membrane, we find
it thin at birth, but at three days (table 4) it increases rapidly
and reaches almost its greatest thickness. This increase in
thickness arises through the apposition of new layers to the
under surface, as Hasse (73) and others have noted, but very
large differences appear between the figures given by various
authors.




131


38 ANATOMICAL AND PHYSIOLOGICAL STUDIES ON


293
Kolliker ('67) finds the membrane 45 n thick in the ox. In
the guinea-pig it is 15 ^ in the thickest place, according to
Schwalbe ('87). Middendorp ('67) gets in mammals generally
a very thin membrane, about 1 n thick. Retzius ('84) states
that in the thickest part in the rabbit it measures 27 [x, in the
cat 32 to 50 |x, and in man 24 to 25 [x. Hardesty finds in the
young pig an average thickness of the teased membrane of
50 [x and in an adult hog 119.3 (x. I get 35 (x as an average in
the adult albino rat after twenty days of age, varying from 32
to 38 [x. My result is therefore closest to that for the cat as
obtained by Retzius. These results are plainly influenced b.y
the dissimilar technical methods used by the several investigators.


About the outermost end of the membrane there are still two
different views. One view is that the outer end of the membrane
projects beyond Hensen's prominence; Kolmer ('07; pig, calf
goat and horse); Hardesty ('15; pig, hog) Shambaugh ('10; pig).
Others assert that the membrane terminates with its outer edge
at the outer boundary of the outermost series of the outer hair
cells. My preparations show that in the rat the outer end of
the membrane does not reach Hensen's prominence.


1.24
Possibly this difference is due to the technique of preparation.  
In the figures drawn by many authors we can recognize many
artifacts and postmortem changes in the cochlea. Even in the
figures of Kolmer ('07) we see these changes, although he injected
the fixing solution through the carotid artery. Held ('09) says
in his criticism of Hardesty 's figures that " figures 6 and 7 wie
schon Hardesty selbst vermutet hat, sicherlich auf einer Verquellung beruhen "


I myself never observed such a gigantic membrane as Hardesty
('08, '15), Shambaugh ('10), and others show in the cochlea
of the pig. On the other hand, I cannot absolutely deny that
there may have been shrinkage in the cochleas prepared by my
methods, though I see no evidence of it.


35
From our present knowledge, however, the method of vital
fixing is considered the best available, as already maintained by
Siebenmann and Yoshii ('08), Metzner and Yoshii ('09), Nager
and Yoshii ('10), Wittmaack and Laurowitsch ('12), and others.


By using this vital-fixation method we get perfect sections which
can be used to solve the problem of the shifting of the organ
of Corti an event which I will discuss later.


546
===2. Membrana basilaris===
The membrana basilaris of the
cochlea stretches between the limbus laminae spiralis and the
ligamentum spirale. The acoustic terminal apparatus is situated
on it and according to the dominant Helmholtz-Hensen theory,
this membrane is to be considered as very important in tone
perception. The row of the fine holes, foramina nervina,
is generally designated as the inner boundary of this membrane.
Strictly speaking, however, the beginning of the membrane is
at the outer edge of the labium tympanicum, which sharpens at
first beyond the foramina nervina and passes over to the substance of the membrana basilaris. Practically it is almost
impossible to decide exactly the point of transition. Thus I
have used in the measurement of the membrane the foramina
of the habenula perforata as an inner limiting line following in
this Retzius, ('84) Schwalbe ('87), and others. Here it is to be
mentioned that the organ of Corti lies with its inner portion
not only upon the inner part of the membrane, but extends to
the foramina nervina also.


The membrana basilaris is usually divided into two portions;
the inner, termed the zona arcuata, and the outer, the zona
pectinata. The former stretches from the habenula perforata
across the base of the tunnel of Corti to the outer edge of the
foot of the outer rods of Corti ; the latter extends from this point
to the ligamentum spirale (fig. 2), 5= inner zone, 10= outer zone.


255
In table 9 (chart 7) are given the values for the total radial
breadth of the membrane, that of each zone, and the ratios
between them. At the bottom of each column are given the
ratios at 1 to 546, 12 to 546, and 20 to 546 days of age. In the
total radial breadth of the membrane, as the table shows, there
are large differences on age from birth to nine days. Between
1 day and three days the increase is 30 |x and between three days
and six days, 28 [A. After nine days the breadth increases more
slowly but continuously to old age.


In the growth of both zones we see about the same relation.
These increase rapidly from birth till nine (or twelve) days and
after that very slowly. These relations are shown clearly in
the ratios at 1 to 546, 12 to 546, and 20 to 546 days. While after
twelve days the ratios in total breadth and in each zone are
the same, 1:1.1, that for 1 to 546 days is smaller for the outer
zone than it is for the inner zone, thus the inner zone increases considerably after birth, while the outer zone does not grow, as some authors have imagined, as much as the inner zone.
I will discuss this point later.


213
{{Wada1923 table9}}




163
Comparing the growths of the radial breadth of the inner
and outer zones, we find that the inner zone is relatively narrow
at nine days; thus the ratios between them are 1:1. 4; after that
period the inner zone increases rapidly, and even at twelve
days the ratio becomes 1:1.1, which is almost the same as in
the adult, 1:1.2.




132
In table 10 the radial breadths of the whole membrane and
of its zones are arranged accordingly to the turns of the cochlea
on age. At the bottom of each column are given the ratios
from 1 to 546, 12 to 546, and 20 to 546 days. We see at first
that the total radial breadth at one day is largest in the basal
turn; at three days it becomes larger on passing from the basal
toward the II and III turns, but in turn IV it is again small.




295


Chart 7 The radial breadth of the membrana basilaris, table 9, figure 2, distance 11.


1.23
Total radial breadth of the membrane.  


Radial breadth of the zona pectinata.


34
Radial breadth of the zona arcuata.


After six days it is a well-known fact that the radial breadth of
the membrana basilaris is narrowest in the basal, and widest
in the apical turn (not the tip of the apex, but the beginning
of the apical turn). These differences are not always the same
between all the turns; those between I and II, and II and III
are marked; those between III and IV are small. The ratios
at 1 to 546 days show those for the upper turn to be largest,
while from 12 to 546, and 20 to 546 days the ratios in all turns
are about 1:1.1.


Ratios 1 546 days




1 1.2


In the zona arcuata (inner zone) the same relation is to be
seen in each turn; therefore, in the early period the breadth
is less in turn IV than in the other turns. Very soon, however,
the value in turn IV becomes the largest and diminishes toward
the base. The rate of the growth of this zone, from 1 to 546 days,
is also smallest in turn I, and largest in turns III or IV; the
ratios being in the first 1:1.6, and in the last 1:2.1.


1 3.6
In the zona pectinata (outer zone) we see also similar relations.  




1 1.7
{{Wada1923 table11}}




Only slight differences in the ratios according to age are found.


In table 11 the ratios according to the turns of the cochlea
are given. While from one to three days the ratios are the same
in each turn, 1:1.0, yet after six days those for turns I to II are
smallest, and for I to IV larger, thus showing slight differences
between them.


1 2.8
In the literature we find only one description, that by Retzius
('84) touching the growth of the radial breadth of the membrana
basilaris according to age. He measured this membrane in the
rabbit and cat and got the following values in n (table 12).  




t 12 546 "
Comparing these values with mine obtained for the albino
rat, it is to be noted that those of Retzius are generally larger
than those for the albino. For example, while I get at birth
only 126 (x in the basal turn, Retzius ('84) obtains 180 [x in the
rabbit and even 270 [x in the cat. As stated above, the radial
breadth increases in the albino rat continuously with age. It
is very peculiar to find in the Retzius table that the breadth
of the membrane in the cat is decidedly larger at birth than at
three and seven days. The average value for the new-born is
315 [x, which is larger than at thirty days, which is 310 [x.


Retzius ' data show the membrane in the rabbit and cat always wider in the apical than in the basal turn at birth and at two days. My results, given in table 10, show the reverse at the ages of one and three days. This is an expression of greater immaturity in the case of the rat.


1.0




1.0
{{Wada1923 table12}}




1.0
In comparisons like the foregoing, several conditions must
be kept constantly in view.  


So far as absolute values are concerned, it is to be expected
that these would be unlike in the different mammals, because
the cochleas differ in size. As to the relations between the values
at birth and at maturity, it is plain that these cannot be expected to agree unless the cochleas of the animals compared
are in the same phase of development at birth. In the foregoing
instances it appears that the cat is relatively precocious, as
compared with the rabbit, while, as might be expected, because of their closer zoological relationship, the rat and the rabbit are
in better agreement, although the rabbit appears to be a trifle
more advanced at birth than the rat.


Finally, in the comparison of different series of data, differences due to the lack of homogeneity in the series of animals
used and to the various techniques employed can hardly fail to
play an important part, and allowance must be made for these
disturbing factors.


When we consider the rate of growth, the ratio of a one to a
fourteen-day-old rabbit is 1:1.6, according to Retzius; therefore, it has very nearly the value found in the albino. In the cat, however, the ratio between one and thirty days is 1:0.97; therefore, it apparently decreases a bit.


1.4


This difference is most readily explained as due to the
precocious development in the cat at birth.


20 5 "
On comparing the radial breadth of the membrane obtained
from several mammals by various authors, we find the following
values (table 13).


{{Wada1923 table13}}


1.0




1.0
The values here given must be read in the light of the various
modifying conditions to which reference has just been made.  


My average value after twenty days is 199 [i; therefore, it
is absolutely the smallest in this series of mammals. The rat
is also the smallest species examined.


1.0
As shown in the literature quoted, and also in my own results,
the membrane increases in its breadth in all the mammals examined from the base toward the apex a relation contrary to
that reported by the older authors (Corti, '51, and others).
This increase is continuous, but is at first more rapid and afterwards more gradual. The ratios of this increase in the albino
rat are given in table 11.  


The next question relates to the breadth of each zone of the
membrane according to age. So far as I know, there is no such
study in the literature, not even in Retzius. In the albino rat,
as shown in table 9, each zone increases in breadth with age.
The rate of growth, however, is somewhat different, and in the
zona arcuata it is greater than in the zona pectinata (1:1.9 and
1 :1.5, respectively), although the absolute value is always greater
in the latter.


As noted above, the membrane increases in its radial breadth
from the basal to the apical turn. How, and in which portion
of the membrane does this increase arise? Henle ('66) first
regarded the breadth of the inner (zona arcuata) as approximately constant.


"Nicht nur in den verschiedenen Regionen einer Schnecke,
sondern, soviel ich sehe, selbst in den Sshnecken verscheidener
Tiere und des Menschen; sie schwankt nur wenig um 0.01 mm."
(Eingeweidelehre des Menschen, 1866, S. 793).


0.9
In the second edition of his book ('73) he states, however,
that in the increase of the breadth according to the turn, both
zones seem to take part. Hensen ('63) gets in the zona arcuata
of the base of the human cochlea the breadth of 19 ^ and in the
apex 85 \L. Middendorp ( '68) gives in the cochlea of the cat a
continuous increase of the breadth of the zona arcuata from 94
to 122.5 {A. ."''"'


More detailed data are given in table 14.


According to all these authors, the breadth of both the inner
and outer zones increases from base toward apex and results in the increase of the total radial breadth of the membrane
according to turn. My results obtained from the albino rat
agree with these data.


in turn III, but after this in turn IV. At the bottom of each
===3. Radial distance between the habenula perforata and the inner corner of the inner pillar cells at base===
column are given the ratios of the radial breadth in each turn
between the several age limits.


These show that after twelve days there is but little change
The measurements of the radial distance from the habenula perforata to the bases of
in the radial breadth of the entire membrane in any turn.  
the inner and outer pillar cells were taken to determine their
postnatal growth. As already stated, the cells from which the
arch of Corti arises stand at birth nearly vertically and have no
space between them (fig. 4). In the adult, however (fig. 10),
we see a space, the tunnel of Corti lying between them and
changes in the form of the arch occur. To follow these changes it seems at first necessary to study the growth of the pillar cells and of the other elements in the organ of Corti. At the
same time we must take into consideration the inward shifting of
the organ of Corti, first studied by Hensen. This shift inward
of the organ is, according to Hensen, chiefly caused by the
wandering of the pillar cells, especially the inner pillar cell.
Therefore, it seemed necessary to determine the radial distance
of the pillar cells from the habenula perforata at different ages
before discussing this interesting problem.


On examining the growth in each zone of the membrane
through the several turns, we find that after three days the outer
zone of the membrane becomes at each age always broader
from base to apex.


{{Wada1923 table14}}


In table 15 are given the values for the radial distances between
the habenula perforata and the inner corner of the inner pillar
cell at its base according to age (figs. 4 to 9). As we see, the
average value increases till three days of age, then vanishes
suddenly, though at six days we have a measurable interval
in the upper turns of the cochlea. Comparing these distances
according to the turn, they are smallest in turn I and increase toward the apex. In some cases, at six days, we have no interval
in the basal turn, but in the higher turns an interval gradually
appears and at the apical turn is largest. This table shows,
therefore, that the inner corner of the base of the inner pillar
cell lies at birth outward from the habenula perforata at an average distance of 22 \L. At three days of age the inner corner
moves farther outward with the developing membrana basilaris
and the distance increases from the base to the apex. Between
three to six days this outward movement not only stops, but
reverses its direction, and at six days it often becomes zero in
the basal turn. Bottcher ('72) finds in the cat the following
values for this interval in \i (table 16).


31


{{Wada1923 table15}}




u
{{Wada1923 table16}}




{{Wada1923 table17}}


200




Retzius ('84) studied this distance in the rabbit and cat and
gets the values given in Table 17.


150
Comparing the values of these two authors with my own,
there are of course some differences. While in the rabbit the
interval is large at one day, it is greatly diminished at two days
of age. At three days the inner corner of the cell reaches the
habenula perforata. In the cat the values are nearer to mine.
The fact that the values increase from base toward apex is to
be seen here also. This peculiar phenomenon appears, therefore
not only in the albino rat, but also in the rabbit and the cat
during the earliest stage of postnatal life.


===4. The radial distance between the habenula perforata and the outer corner of the inner pillar cell (resp. the inner corner of the outer pillar cell) at base===


This measurement is difficult. As we
know, the inner and outer pillar cells in the albino are from birth
till nine days of age in contact with each other along their whole
length, and therefore they do not yet surround the space forming
the tunnel of Corti. At about nine days, however, the tunnel
appears while the cells remain in contact by their bases. It
is almost impossible to determine the line of contact on the
basilar membrane in my preparations. To get the radial distance
between the habenula perforata and the outer corner of the inner
pillar cell I have proceeded therefore as follows:


100
First, I have measured this distance directly up to nine days
of age; after that this distance consists of the sum of the radial
basal breadth of the inner pillar (not pillar cell) and the breadth
of the inner basal cell on the basilar membrane. Since it is
impossible to get the latter value directly in my sections, I
considered that half of the radial distance between the outer
corner of the inner pillar and the inner corner of the outer pillar
would be equivalent to it.


Of course, I do not know whether the value of the sum of
these two distances is at all ages, identical with the distance
between the habenula perforata and the outer corner of the inner
pillar cell at its base. I believe, however, that a systematic
study of the growth of this distance will be significant.




50
In table 18 are given the values for the radial distance between
 
the habenula perforata and the outer corner of the inner pillar
at base up to nine days of age. As shown, these values, on the
average, increase with age. The increase of this distance means
that the base of the inner pillar cell spreads outward more and
more.


When we consider this distance according to the coil of the
cochlea, it is at birth about the same through all the turns
(table 18; at three days it increases up to turn III, and in turn IV the value is the same at the apex as at the base. At six days the value in turn III is also largest, and next largest in turn IV.
At nine days of age the same relations are to be seen.


o
{{Wada1923 table18}}






AGE QAYSH
In table 19 (chart 8) are given the values for the radial basal
i i
breadth of the inner pillar (not pillar cell) on age. At the bottom
of the last column are the ratios from 6 to 546, and 20 to 546
days. As above noted, the rod can be followed at birth from
the upper part to near the base of the cell (fig. 4). At three days
(fig. 5), its base reaches the basilar membrane as a thin and slender
thread, but we cannot measure its basal breadth accurately.
During the next few days it increases in radial breadth rapidly,
and at six days has the average value of 29 [/. (table 19). After
nine days it decreases distinctly till twenty days, after which
the value remains nearly constant. These relations are evident
in the ratios. While the breadth at six days is about twice
that at 546 days, that at twenty days has the same value.


According to the turn of the cochlea, the values from nine
to fifteen days become gradually larger on passing from the
base toward the apex. After twenty days, however, this relation
vanishes, and the values become nearly the same through all




O
{{Wada1923 table19}}




Chart S. The radial basal breadth of the inner pillar (not pillar cell),
table 19, figure '2, distance 3.


25
the turns. In table 20 the ratios of the turns I to II, I to III,
and I to IV are given for three age groups (condensed from table




From the data given by Retzius ('84) we get the values in jx
of the radial basal breadth of the inner pillar in the rabbit and
cat as follows (table 21).


50
Comparing these values with my own, it is to be noted that
Retzius' measurements in the rabbit agree perfectly at the
earliest stage with those in the albino rat. Also we find in the rabbit at seven days values homologous with those obtained in the albino rat at fifteen days of age, only in the rat the breadth
is absolutely greater. In the cat the values at seven days of
age are about the same, or a bit smaller, than those in the albino
rat. Here again the rabbit is a trifle more precocious than the
rat, and the cat much more so.






5O 10O 2OO 3OO 4OO 50O
{{Wada1923 table20}}




Table 22 (chart 9) shows the values for the radial distance
between the outer corner of the inner pillar (not pillar cell) and the inner corner of the pillar (not pillar cell) at the base,
on age. At the bottom of the last column are given the ratios
from 6 to 546, 12 to 546, and 20 to 546 days. As just stated,
the inner, and especially the outer rods, do not appear in the
respective pillar cells at the earliest stage, the latter becoming
evident a bit later than the former. After six days of age the
distance between them can be determined.


Chart 2 The radial breadth of membrana tectoria, table 4, figure 1.
Total radial breadth of the membrane.


Radial breadth of outer zone.
{{Wada1923 table22}}


*- Radial breadth of inner zone.


Chart 9. The radial distance between the outer corner of the inner pillar
(not pillar cell) and the inner corner of the outer pillar (not pillar cell) at base,
table 22, figure 2, distance 6.




25 50 50 10O 2OO 3OO 4OO 5OO


Chart 3 The thickness of membrana tectoria, table 4.  
As table 22 shows, this distance increases at first rapidly,
then more slowly with age. This agrees with the growth of the
membrana basilaris, as already noted. While the value at 546
days is over twice as large as at six days, it is but little larger
than at twenty days, as the ratios show. Moreover, the distance
increases from the base toward the apex rapidly up to turn




{{Wada1923 table23}}


32


III and less rapidly to turn IV. This relation is more concisely
presented in table 23. Retzius ('84) gives the value of this
distance in the rabbit and the cat as follows (table 24).


The table 24 shows that there is no measurable distance
between the outer corner of the inner pillar and the inner corner
of the outer pillar at the very early stage in the rabbit, and this
result is like that for the albino rat. Later the distance is larger
in the rabbit than in the rat. The rate of increase of the values
from the base to the apex is, however, similar in both forms.
In the cat, on the other hand, there is already at birth a large
distance between the pillars. The cochlea of the cat is therefore at this period more advanced in this character than that of
the rabbit or rat, but in the cat also the distance tends to increase from the base toward the apex.


ANATOMICAL AND PHYSIOLOGICAL STUDIES ON


In table 25 (chart 10) are given the values for the radial
distance between the habenula perforata and the outer corner
of the inner pillar cell (resp. the inner corner of the outer pillar
cell) at the base according to age. This table is derived from
tables 18, 19, and 22. The values from one to nine days of age
are from table 18. Those after twelve days consist of the sum
of the values in table 19 plus the one-half of those given in table
22 (fig. 2 value for bracket 3 plus one-half the value for bracket
6).




ta o
{{Wada1923 table24}}


i
< -S




The values increase gradually after birth till nine days, when
they reach a maximum, and then decrease, but increase again
very gradually till old age. If this method of measurement is
accepted, then the inner corner of the inner pillar cell lengthens
inward at the base in the earlier stages. At the time when the
inner pillar reaches the habenula perforata, the outer corner
of the inner pillar has not yet moved inward, and thus the breadth
of the base is largest. After the inward wandering of the inner
pillar cell, the base diminishes a little in its breadth; then it
increases slightly with advancing age.


a
When considered according to the turn of the cochlea, this
measurement generally increases from the base to the apex,
but more rapidly from turn I to turn III, and only slightly from turn III to IV. Table 26 shows this relation. While at birth
the ratio is in all turns the same, 1 :1.0, at other ages it is always
higher. Retzius ( '84) gives the results obtained from the rabbit
and the cat as follows (table 27).


2
S
BS


{{Wada1923 table25}}




.  
Chart 10 The radial distance between the habenula perforata and the
outer corner of the inner pillar cell (resp. the inner corner of the outer pillar
cell) at base, table 25, figure 2, distance 8.  




{{Wada1923 table26}}


n w


it


TABLE 27




T^cOTtiCO-'^
-HOOOOOO


Distance between the habenula perforata and the outer corner of the inner pillar


cell in n (Retzius)


o; (




Age


o;^ ^-^


Basal
turn




(N 00
Middle


turn




OOOOOOOO
Apical
turn




Average
turn


co o !o


Basal
turn




rH O
Middle
turn




Apical
turn


rH O


Average
turn




>> ^
days


c3






1 O I






rH'HCScouv.S "3:uj
W i i
' co






20-546






GBOWTH OF THE INNER EAR OF ALBINO RAT






33




New-born


The values at birth are relatively greater than those at three
days, as noted above, due to the undevelopment of the labium
vestibulare. The inner zone grows in a like manner in breadth,
but not so rapidly as the outer zone, and hence its relative breadth
diminishes gradually from base to apex.


Table 6 shows these relations. While the ratios in the inner
30
zone decreases from base to apex, those in the outer zone increase.
Thus the ratios in the inner and outer zones according to the
turns go in opposite directions. As stated above, the radial
breadth is generally larger in the outer zone, but this relation
is, in general, reversed in turn I, table 5.


TABLE 6 Condensed
Ratios of the radial breadth of each zone of the membrana tectoria


45




39




38




Ratios according to turns of the cochlea
60




60




60




60




2




Ratios between inner and
30




36




BOOT
30




INNER CONE
32




OUTER ZONE




outer zone




AGE




__ fjfi**T




Line 2,265: Line 2,667:




3




Line 2,271: Line 2,674:




Turns




Turns




Turns








44




I-II
60




I-III




I-IV




I-II




I-II I
7




I-IV
37




I
46




II
45




in
43




IV
45




days
69(?)




grams
65




60




10




39




52




48




46




Line 2,340: Line 2,744:




1




5




1:0.8
11




1:0.5




1:0.0




1:1.2




1:1.3




1:1.4




1:1.8




1:2.8
60




1:4.3
66




1:0.0
75




8
67




11
14




:0.9
40




:0.9
54




:0.8
51




:1.4
48




:1.8




:1.9




:0.8




:1.2




:1.6




:2.0




18
30




21




:0.9




:0.9




:0.8




:1.4




:1.8




:2.0




:0.8


60


:1.1


60


:1.5




:1.9




203


At the earlier stage this distance in the rabbit is a little less
than in the rat. Soon after, however, it becomes about the same.
In the cat the values are generally larger than in the rat.


160
===5. Radial basal breadth of the outer pittar cett (including the outer pillar)===


The measurement of the radial basal breadth
of the outer pillar cell is difficult. At the earlier stage, in which the
inner and outer pillar cells are in contact with each other along


:0.9




:0.9
Radial basal breadth of the outer pillar cell (including the outer pillar) from one


to nine days of age


:0.8




:1.4




:1.7




:2.0
TURNS OF THE COCHLEA M




:0.8
AGE




:1.1
BODY WEIGHT




:1.5




:1.8






In turn I the average ratios are, after eight days, smaller than
1.0; therefore, the inner zone is wider than the outer in turn I.
It increases in all ages from turn II toward the apex.


In table 7 are given the ratios between each turn of the cochlea.
I  
The ratios after nine days of age are practically constant according
to age, but those between turns I and II are always smaller
than the others; the ratios for the two latter being alike. The
ratio at one day is, however, an exception, as stated already.


As the measurements show, the membrana tectoria is at birth
relatively undeveloped; it is thin and immature. After birth
it increases rapidly during the first nine days, a statement which
applies generally to the postnatal growth of the organs of the
albino rat. Thus we get a ratio of the radial breadth 1 :1 .7 between
1 and 546 days, but after twelve days the ratios remain practically 1:1.0. (Table 4.)


II




ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
III




IV


It is not my purpose to describe the fetal development of
the membrana tectoria, but it is worth while to consider briefly
the zones which compose the membrane; in other words, the parts
of the tympanic wall from which it originated. There are chiefly


TABLE 7
Average


Ratios of the radial breadth of the membrana tectoria according to the turns of the


cochlea
days




grams


AGE


1


BODY WEIGHT


5


Ratios according to turn of the cochlea


10


I-II


9


I-II I


8


I-IV


8


days


9


gms.


3




8




15




16


1


15


5


12


1 1.0


15


1 1.0


6


1 :0.9


11


3


26


8


28


1.2


28


1.2


33


:1.2


28


6


9


11


10


1.2


26


1.4


30


:1.3


30


9


35


10


30


1.1




1.3
TABLE 29
Radial basal breadth of the outer pillar on age (chart 11)




:1.3


AGE


12


BOOT WEIGHT


13


TURNS OF THE COCHLEA M


1.1


I


1.3


II


:1.3


III


15


IV


13


Average


1.1


days


1.3


grams


:1.3




20




29




1.1




1.3




:1.3


1


25


5


36




1.1




1.3




:1.4




50




59




1.1




1.3




: 1.3  
3  




100
S




112




1.1




1.3




:1.4




150




183




1.1




1.3


6


: 1.3


11


257


10


137


14


1.1


16


1.3


17


:1.3


14


366


9


181


10


1.1


15


1.3


18


:1.3


18


546


21


255


18


1.1


12 .


1.3


13


:1.3


14




Chart 4 The total radial breadth of membrana tectoria arranged according
23
to the turns of the cochlea, table 5.


About middle part of the basal turn (I).


About the beginning of the middle turn (II).
25


About the middle part of the middle turn (III).


About the beginning of the apical turn (IV). 2
22


Chart 5 The radial breadth of the inner zone of the membrana tectoria,


according to the turns of the cochlea, table 5.
21


Chart 6 The radial breadth of the outer zone of the membrana tectoria,


according to the turns of the cochlea, table 5.
15


* In most cases when the values which have been determined are analyzed
according to the turns of the cochlea, it is found that they increase with later
growth from the basal (I) to the apical (IV) turn and in the order just given in
chart 4. Owing to this uniformity of behavior, some thirteen charts showing
the several values according to turn have been omitted, since the graph given
by the average value is sufficiently informing in each instance.


In the case of those charts which have been retained, and in which the
13
measurements are according to the turns of the cochlea, the respective turns
I-IV are recorded by characteristic lines similar to those used for them in
chart 4, and in these cases the further designations of the turns are omitted.




17


350


21




300
23




20


I


20




ISO
20




29


G.E DAYSH


13




13




16




25 5O
15




14


50 1OO 2OO 30O 400 500


Chart 4
25




36


150


14




1OO
13




14


50


14




14




50




AGE
59
 
 
14




14


25 50 50 1OO 200 300 4OO 500


Charts
15




14


180


14




Line 2,862: Line 3,210:




112


DAYS
 
14




25 50 5Q 1OO 2OO 3OO 4OO 5OO
15


Chart 6


16




36
15


two views about this. While a few authors, Kolliker ('67),
Hensen ('63), and recently Hardesty ('08, '15), and others hold
that only the greater epithelial ridge takes part in the formation
of the membrane, most investigators (for example, Bottcher,
'69; Retzius, '84; Rickenbacher, '01; Held, '09; Van der Stricht,
'18) consider that it originates from both the greater and lesser
epithelial ridge. My figure 5, supports the latter view; that is,
while the main part is developed from the greater ridge, the
outer narrow marginal part is secreted from the lesser ridge.


The figure in Quain's Anatomy by Schafer ('09) (vol. 3, part
15
2, p. 332, llth ed.,) is from the earlier paper of Hardesty and
shows the membrane in the pig as arising from the greater
epithelial ridge only.


Hardesty has corrected this figure in his paper published in
1915. Thus in the very early stage after birth in these forms
we have three zones, an inner, an outer, and a marginal zone.
With age, however, this marginal zone becomes, as Held ('09)
and others agree, gradually smaller and smaller, and finally
it is difficult to differentiate it from the outer zone. Thus for
convenience in measurements I have treated the membrane as
consisting of two zones only.


Comparing the breadth of the inner and outer zones, it is
150
evident that the outer is always the broader. The ratio is
(table 4) at birth 1 : 3.78, at three days 1 : 1.43, and then gradually
diminishes to 1:1.23 with age.


Now if we examine the ratios of the total breadth of the
membrane according to the turns of the cochlea, we find after
six days that the ratio generally increases from base to apex,
and that these ratios remain nearly constant after nine days
of age, as shown in table 7.


Thus the ratio between turns I and II is 1:1.1; between turns
183
I and III, 1:1.3; between turns I and IV, 1:1.3. The breadth
of the membrane increases, -therefore, in the albino rat gradually
from the base to the middle part of the middle turn; from this
point it does not increase to the apex.


Since the breadth at the tip of the apex diminishes greatly,
as is generally recognized, Hardesty ('08) found in the pig the
following ratios (table 8):


15




GROWTH OF THE INNER EAR OF ALBINO RAT
15




15


37


16




Comparing these ratios obtained by Hardesty in the pig with
15
mine, there appear to be large differences between them. The
reason for these I will discuss later.


When we consider the breadth in each part of the membrane
according to the turn, we find that the increase of the breadth
of the membrane in each turn is due to the development of the
outer zone. The inner zone, which is adherent to the labium
vestibulare, does not increase in the rat as Hardesty ('08/15)
found to be the case for the pig, but on the contrary decreases
from base to apex a relation found by Retzius ('84) in the rabbit,
cat, and man and confirmed by Rickenbacker ('01) in the guineapig. On the contrary, the outer zone increases in breadth from


TABLE 8
257
Ratios of the breadth of the membrana tectoria according to turn of cochlea (Hardesty)




137


Kind of animal


15


Preparation
method


16


Ratios between
breadth in 7 and
5 half turn


17


Ratios between
7 and 3 half turn


17


Ratios between
7 and 1 half turn


16


Pigs two weeks
of age


366


Membrane
teased out
Membrane


181


1 : 1.4


15


1 :1.7


16


1 :2.5


17




18


teased out


16


1 :1.8


546


1 :2.5


255


1 :2.7


16


Adult


15


Membrane in


17




17




16






Ratios


1
2


section
40
A
20


n


1 : 1.6


6546 days 1
2546 "
0546 "


1 :2.1


1.1
0.8
1.1


1 :1.8






base to apex, and in each stage the ratios between the successive
turns are nearly the same. These ratios between successive
turns, however, show rather large differences according to the
different authors.


My results (table 5) show that the outer zone in the albino rat
is nearly two times wider at the apex than at the base. This
agrees with what von Ebner ('02) finds in the human cochlea.


When we consider the thickness of the membrane, we find
Chart 11 The radial basal breadth of the outer pillar (not pillar cell)  
it thin at birth, but at three days (table 4) it increases rapidly
table 29, figure 2, distance 7.  
and reaches almost its greatest thickness. This increase in
thickness arises through the apposition of new layers to the
under surface, as Hasse (73) and others have noted, but very
large differences appear between the figures given by various
authors.  






38 ANATOMICAL AND PHYSIOLOGICAL STUDIES ON


Kolliker ('67) finds the membrane 45 n thick in the ox. In
their whole length, we can easily measure this distance. After
the guinea-pig it is 15 ^ in the thickest place, according to
twelve days, however, the breadth consists of the sum of the  
Schwalbe ('87). Middendorp ('67) gets in mammals generally
radial breadth of the outer pillar and the half of the radial
a very thin membrane, about 1 n thick. Retzius ('84) states
distance between the outer corner of the inner pillar and the
that in the thickest part in the rabbit it measures 27 [x, in the  
inner corner of the outer pillar, as previously explained.  
cat 32 to 50 |x, and in man 24 to 25 [x. Hardesty finds in the  
young pig an average thickness of the teased membrane of
50 [x and in an adult hog 119.3 (x. I get 35 (x as an average in
the adult albino rat after twenty days of age, varying from 32
to 38 [x. My result is therefore closest to that for the cat as  
obtained by Retzius. These results are plainly influenced b.y
the dissimilar technical methods used by the several investigators.  


About the outermost end of the membrane there are still two
In table 28 are given the values for the radial basal breadth
different views. One view is that the outer end of the membrane
of the outer pillar cell (including the outer pillar) from birth
projects beyond Hensen's prominence; Kolmer ('07; pig, calf
to nine days of age. These values show a rapid increase. According to the turn of the cochlea, the breadth at birth diminishes
goat and horse); Hardesty ('15; pig, hog) Shambaugh ('10; pig).
from the base to the apex. At three days it increases already in  
Others assert that the membrane terminates with its outer edge
turn II, but at the later ages it increases gradually from the  
at the outer boundary of the outermost series of the outer hair
base to the apex.  
cells. My preparations show that in the rat the outer end of
the membrane does not reach Hensen's prominence.  


Possibly this difference is due to the technique of preparation.
TABLE 30 Condensed
In the figures drawn by many authors we can recognize many
artifacts and postmortem changes in the cochlea. Even in the
figures of Kolmer ('07) we see these changes, although he injected
the fixing solution through the carotid artery. Held ('09) says
in his criticism of Hardesty 's figures that " figures 6 and 7 wie
schon Hardesty selbst vermutet hat, sicherlich auf einer Verquellung beruhen "


I myself never observed such a gigantic membrane as Hardesty
Ratios of the radial basal breadth of the outer pillars on age according to the  
('08, '15), Shambaugh ('10), and others show in the cochlea
of the pig. On the other hand, I cannot absolutely deny that
there may have been shrinkage in the cochleas prepared by my
methods, though I see no evidence of it.


From our present knowledge, however, the method of vital
turns of the cochlea
fixing is considered the best available, as already maintained by
Siebenmann and Yoshii ('08), Metzner and Yoshii ('09), Nager
and Yoshii ('10), Wittmaack and Laurowitsch ('12), and others.






GROWTH OF THE INNER EAR OF ALBINO RAT 39


By using this vital-fixation method we get perfect sections which
can be used to solve the problem of the shifting of the organ
of Corti an event which I will discuss later.


2. Membrana basilaris. The membrana basilaris of the
cochlea stretches between the limbus laminae spiralis and the
ligamentum spirale. The acoustic terminal apparatus is situated
on it and according to the dominant Helmholtz-Hensen theory,
this membrane is to be considered as very important in tone
perception. The row of the fine holes, foramina nervina,
is generally designated as the inner boundary of this membrane.
Strictly speaking, however, the beginning of the membrane is
at the outer edge of the labium tympanicum, which sharpens at
first beyond the foramina nervina and passes over to the substance of the membrana basilaris. Practically it is almost
impossible to decide exactly the point of transition. Thus I
have used in the measurement of the membrane the foramina
of the habenula perforata as an inner limiting line following in
this Retzius, ('84) Schwalbe ('87), and others. Here it is to be
mentioned that the organ of Corti lies with its inner portion
not only upon the inner part of the membrane, but extends to
the foramina nervina also.


The membrana basilaris is usually divided into two portions;
the inner, termed the zona arcuata, and the outer, the zona
pectinata. The former stretches from the habenula perforata
across the base of the tunnel of Corti to the outer edge of the
foot of the outer rods of Corti ; the latter extends from this point
to the ligamentum spirale (fig. 2), 5= inner zone, 10= outer zone.


In table 9 (chart 7) are given the values for the total radial
RATIOS BETWEEN TURNS
breadth of the membrane, that of each zone, and the ratios
between them. At the bottom of each column are given the
ratios at 1 to 546, 12 to 546, and 20 to 546 days of age. In the
total radial breadth of the membrane, as the table shows, there
are large differences on age from birth to nine days. Between
1 day and three days the increase is 30 |x and between three days
and six days, 28 [A. After nine days the breadth increases more
slowly but continuously to old age.




AGE


40


BODY WEIGHT




ANATOMICAL AND PHYSIOLOGICAL STUDIES ON






In the growth of both zones we see about the same relation.
These increase rapidly from birth till nine (or twelve) days and
after that very slowly. These relations are shown clearly in
the ratios at 1 to 546, 12 to 546, and 20 to 546 days. While after
twelve days the ratios in total breadth and in each zone are
the same, 1:1.1, that for 1 to 546 days is smaller for the outer
zone than it is for the inner zone, thus the inner zone increases


TABLE 9


Radial breadth of Ihe membrana basilaris measured between the foramina nervina
and ligamentum spirale in radial sections on age (chart 7, fig. 2}


I-II




AGE
I-III




BODY WEIGHT
I-IV




INNER ZONE
days


(Zona
arcuata)


grams


OUTER ZONE


(Zona
pectinata)




Total radial
breadth of
the membrane




Ratios between
the radial breadth
of the inner and
outer zone




days
8




grams
11




P
1 -1.2




M
1 1.3




M
1 1.5




M
14




1
13




5
:1.4




49
1.5




75
1.3
 
 
189




Line 3,218: Line 3,442:




1 1.5
: 1.0




3
1.1




8
1.1




63


In table 29 (chart 11) are given the values for the radial
basal breadth of the outer pillar (not pillar cell). As in the case
of the inner pillar, here also the outer pillar first appears distinctly
at six days of age. After the continuous increase of the values till
twelve to fifteen days, they decrease suddenly at twenty days,
and then increase again very slowly. This relation is clearly
shown by the ratios at the bottom of the last column. That
the values tend to increase from the base toward the apex is
also shown, though there are some exceptions. Table 30 gives
the condensed results.


91
From Retzius' work ('84) we have calculated the values for
the radial basal breadth of the outer pillar in the rabbit and cat
as follows (table 31).


There are large differences between my results and those
of Retzius during the earlier stage, especially in the rabbit.


154




1.5
60




6


ANATOMICAL AND PHYSIOLOGICAL STUDIES ON


11




77
At birth, the inner pillar has not yet distinctly developed at
the base of the pillar cell in the rabbit and the rat, as above
stated. We know that the development of the elements of
the cochlea proceeds generally from the axis to the periphery, as


TABLE 31


105
Radial basal breadth of outer pillar measured in n (from Retzius)




182


RABBIT


1.4


CAT


9 1


Age


10


Basal
turn


79


Middle
turn


111


Apical
turn


190


Average


1.4


Basal
turn


12


Middle
turn


13


Apical
turn


- 88


Average


100


days


188


,


1.1




15


New-born


13


15?


87


12?


102


7?


189


11?


1.2


25


20


15


29




86




106




192


2


1.2


50


. 25


45


36


44


87


46


108




195




1.2




50




59




88




107


3


195




1.2




100




112




92




106




Id8


20


1.2




150




183




92




107




199
7




1.2
28




257
28




137
17




92
24




107
18




199
20




1.2
18




366
19




181
10




93
31




111
30




204
37




1.2
33




546




255




94




113




207




1.2




Ratios 1 546 days
11




1 1.9




1 1.5




1 1.7








12546 "




1.1




1.1
30




1.1
19








20546 "




1.1




1.1
14




1.1
28




25




1 A rat of nine days which could hear, gave the following:
18




Right side 11
24




94




103




197




Line 3,516: Line 3,725:




91




104
30




195




Line 3,529: Line 3,736:




93




104




196




1 : 1.1
10




15


considerably after birth, while the outer zone does not grow,
as some authors have imagined, as much as the inner zone.
I will discuss this point later.


Comparing the growths of the radial breadth of the inner
15
and outer zones, we find that the inner zone is relatively narrow
at nine days; thus the ratios between them are 1:1. 4; after that
period the inner zone increases rapidly, and even at twelve
days the ratio becomes 1:1.1, which is almost the same as in
the adult, 1:1.2.




13


GROWTH OF THE INNER EAR OF ALBINO RAT




TABLE 32


41




Radial basal breadth of the outer pillar cells on age, based on tables 22, 28, and


In table 10 the radial breadths of the whole membrane and
29 (charts 12 and 18)
of its zones are arranged accordingly to the turns of the cochlea
on age. At the bottom of each column are given the ratios
from 1 to 546, 12 to 546, and 20 to 546 days. We see at first
that the total radial breadth at one day is largest in the basal
turn; at three days it becomes larger on passing from the basal
toward the II and III turns, but in turn IV it is again small.






220
AGE


M
180


140
BODY WEIGHT
100
60
20




TURNS OP THE COCHLEA M




I




II




III




IV




Average




days




grams




Line 3,610: Line 3,805:




1




5




10




9




8




8




9




3




8




15




16




15




12




15




6




11




26




28




28




33




28




9




10




26




30




30




35




30




12




13




33




38




48




52




43




15




13




35




44




50




48




44




20




29




35




40




49




49




43




25




36




35




42




48




48




43




50




59




35




41




49




51




44




100




112




36




45




i
52




54




47




150




183




36




45




*
49




54




^
46


i


-^
257




137




38




44




50




53




46




366




181




38




43




51




55




47




546




255




40




45




53




54




48






Ratios 1 546 days


9546 "
12546 "
20546 "






1 :5.4
: 1.6
: 1.1
: 1.1




Held ('09) and others have pointed out. Yet, according to
Retzius, the outer pillar develops in the rabbit earlier than does
the inner pillar. This result seems to me very peculiar, but,
at present, I am unable to explain it.


In table 32 (charts 12 and 13) are given the values for the
radial basal breadth of the outer pillar cells. These data are derived from tables 22, 28, and 29. At the foot of the last column are given the ratios from 1 to 546, 9 to 546, 12 to 546, and 20
to 546 days. The values increase rapidly during the earlier
stage, but after twelve days very slowly, as the ratios show.
The breadth is, at birth, largest in the basal and smallest
in the apical turn. Very soon, however (six days), the reverse relation appears, and the breadth increases from the base
to turn III relatively rapidly, but from turn III to IV slowly.
In table 33 the ratios are given in a condensed form. The radial
breadth of the outer pillar cells as given by Retzius ('84) are
as follows (table 34.)








Chart 13 The radial basal breadth of the outer pillar cell, according to
the turns of the cochlea, table 32, figure 2, distance 9.






/




'
TABLE 33 Condensed


Ratios of the radial basal breadth of the outer pillar cells on age according to


turns of cochlea




Line 3,839: Line 4,152:




RATIOS BETWEEN TtTRNS




AGB




BODY WEIGHT




Line 3,851: Line 4,167:




I-II




i-in




I-IV




days




grams




Line 3,867: Line 4,188:




1




5




1 :0.9




1 0.8




1 :0.8




8




11




1 1.1




1.2




:1.3




18




21




:1.2




1.4




: 1.4




213




138




:1.2




1.4




: 1.4






TABLE 34
Radial basal breadth of the outer pillar cells in n (Retzius)






RABBIT




CAT




AOE




Basal
turn




Middle
turn




Apical
turn




Average
turn




Basal
turn




Middle
turn




Apical
turn




Average
turn




days






New-born




21




22




23




22




36




30




30




32




3




30




40




30




33




Line 3,976: Line 4,353:




3




Line 3,990: Line 4,368:




36




30




Line 4,000: Line 4,380:




7




65




66




60




64




36




54




36




42




10




52




60




69




60




Line 4,037: Line 4,431:




'




11




Line 4,053: Line 4,449:




50




60




18




43




14




57




80




80




72




Line 4,083: Line 4,488:




30




Line 4,088: Line 4,494:




1




Line 4,104: Line 4,506:




60




60




Line 4,112: Line 4,516:




This table shows that the breadth of the outer pillar cell increases in the rabbit and the cat continuously from birth to
old age, as I have found in the rat. Also the value is generally
smallest in the base, largest in the apex, though there are some
exceptions. The main differences between the results of Retzius
and mine is that the values in the rabbit are larger than in the
rat. This is probably due to the differences in the size of the
animals.




===6. The radial distance between the habenula perforata and the outer border of the foot of the outer pillar cell===




The determination of this distance is deemed necessary not only as a datum
on growth in general, but also for its bearing on the difficult
question of the shifting of the outer pillar cell, to be discussed
later. On the other hand, this distance is identical with the
radial length of the zona arcuata of the membrana basilaris
(table 7. inner zone).


In table 35 (chart 14) are given the values for the radial
distance between the habenula perforata and the outer corner
of the outer pillar cell at base. At the foot of each column are
given the ratios at 1 to 12, 1 to 20, 1 to 546, and 20 to 546 days.
As table 35 shows, the distance increases continuously from birth
to old age, rapidly up to twelve days, but later gradually. Up
to three days the distance is slightly larger in the lower turns, but
after this age the relation is reversed, and this persists through life.


The increasing ratio of the distance for each turn according
to age is smallest in turn I and largest in turn IV. The ratios
for the condensed data are given in table 36. While the ratio
at birth is the same in each turn, 1:1.0, that of turn I to II is
smallest for every condensed age. Also it is to be seen that the
increase of the ratio in turn I to II is smallest and that in turns
I to IV is largest. In Retzius' work ('84) we find the following
values for this distance (table 37).


Table 37 shows that in the rabbit the growth changes are
similar to those in the rat, though the absolute values are somewhat
larger. As hi preceding determinations, the values for the cat
do not stand in the same relation as those for the rabbit, but
indicate precocity. Some corresponding observations by Hensen,
Bottcher, and others will be presented later.


===7. The greatest height of the greater epithelial ridge (der grosse Epithelwulst (Bottcher) s. Organon Kollikeri) resp. of the inner supporting cells===


(fig. 4, G). The so-called greater epithelial ridge
is a prominence formed by high cylindrical pseudostratified cells.
It is situated axialward on the tympanic wall and continued
outward to the lesser epithelial ridge. About the fate of this
ridge there were various divergent opinions among the older authors. Now, the view of Bottcher ( '69) is generally accepted.
This large prominence vanishes during development, and instead
of it a deep and wide furrow lined with low epithelium appears.
These epithelial cells become peripherally higher and finally lean




{{Wada1923 table35}}






Chart 14 The radial distance between the habenula perforata and the
outer corner of the outer pillar cell at base, table 35, figure 2, distance 5.






on the inner supporting cells, which are termed ' Grenzzellen '
by Held ('02). The latter belong, of course, to this ridge, since
the inner hair cell marks the outmost row in the ridge. The
'Grenzzellen' of Held, however, are different from other high
cylindrical cells in the ridge, as they have a very intimate relation
with the ' Phalangenzellen ' of Held, stand with their bases just


TABLE 36 Condensed


Ratios of the radial distance between the habentda perforata and the outer corner
of the outer pillar cells at base on age




Line 4,138: Line 4,599:




RATIOS BETWEEN TURNS




AVERAGE AGE




AVERAGE BODY




Line 4,148: Line 4,612:




WEIGHT




I-II




i-in




I-IV




days




/
grams




Line 4,167: Line 4,636:




1




5




1 :1.0




1 :1.0




1 :1.0




8




11




: 1.1




:1.3




: 1.2




18




21




:1.2




: 1.4




: 1.4




213




138




: 1.2




: 1.3




: 1.4






TABLE 37


Radial distance between habenula perforata and the outer corner of the outer pillar
cells at base in n (Retzius)






RABBIT




CAT




Age




Basal




Middle




Apical




Average




Basal




Middle




Apical




Average








turn




turn




turn




turn




turn




turn




turn




turn




days




Line 4,270: Line 4,782:




New-born




75




80




75




77




105




105




120




110




2




80




90




100




90






.-.<




Line 4,311: Line 4,836:




3


~ ^








1




Line 4,323: Line 4,847:




'








80


*


120




Line 4,339: Line 4,863:




7


"


100




115




107




107




78




110




120




103




10




100




120




129




116




Line 4,380: Line 4,917:




11




Line 4,394: Line 4,932:




120




129




108




119




14




106




140




129




125




Line 4,424: Line 4,971:




30




Line 4,438: Line 4,986:




85




120




120




108






outward from the habenula perforata and serve to support the
inner hair cell as Deiters' cells support the outer hair cells.


Thus the greater ridge includes in its prominence three kinds
of cells, the high cylindrical cells, the 'Grenzzellen' of Held and
the inner hair cell.


The greatest height of this ridge is not situated at a fixed
point, but first lies somewhat outward from the middle part and






66






ANATOMICAL AND PHYSIOLOGICAL STUDIES ON






after the furrow appears, passes outward towards the inner
supporting cells. Thus the greater ridge decreases in thickness
from birth to nine days of age, then increases gradually to twenty
days. After twenty-five days the values diminish again very
slowly but continuously.


In table 38 (charts 15 and 16) are given the values of the greatest
height of the greater epithelial ridge from the basilar membrane


TABLE 38


Greatest height of the greater epithelial ridge (resp. of the inner supporting cells)


on age (charts 15 and 16)




_






Bodv wcifitlitj




TURNS OF COCHLEA M




Line 4,476: Line 5,048:




I




II




III




IV




Average
height




days
1




grams
5




68




65




66


.


63




66




3


/


8




49




49


JH


56




57


-


53




6




11




''
40




40




1
41




"
40




40




9




10




36




40




41




42




40




12




13




38




41




48




53




45




15




13




44




46




52




58




50


r


20




29




50




53




63




66




58




25




36




51




51




63




63




57




50




59




50




50




59




63




56




100




112




48




49




59




63




55




150




183




47




49


r


56




61




53




257




137




47




51




56




62




54




366




181




46




49




57




60




54




546




255




44




50




56




60




53




Ratios 1 9 days 1:0.6




12 20 " :1.3




12546 " :1.2




20546 " :0.9




1546 " :0.8






through the summit of the supporting cells, according to age.
At the bottom of the last column is given the ratio at 1 to 9,
1 to 546, 12 to 20, 12 to 546, and 20 to 546 days of age.


The values in turn I are at birth the largest, but at three
days the relation is reversed and remains so in the later age
groups. Table 39 shows this relation from the condensed data.


Retzius ('84) gives in the rabbit and cat the following values
(table 40).


In the rabbit the values decrease from birth till ten days,
then increase; therefore, they agree in general with my results






;
50
40
30






;






25






50 50 10O 20O 30O 40O 500


Chart 15 The greatest height of the greater epithelial ridge (resp. of the
inner supporting cells) table 38, figures 4 to 12.






70
44


60


5O
40
30






s






o






25






50






50 IOO 20O 3OO 4OO 500






Chart 16 The greatest height of the greater epithelial ridge (resp. of the
inner supporting cells) arranged according to the turns of the cochlea, table 38,
figures 4 to 12.


on the rat, while in the cat they diminish from birth till thirty
days though irregularly.


The absolute values are greater for the rabbit than for the
rat during the earlier stage, but afterwards they are similar.






68






In the cat the early data give values similar to those for the rat,
but the later values are lower.


Bottcher's observations ('69) on the cat, calf, and sheep also
give larger values than mine. In the cat the greater ridge has
an average height of 75 [x and in both the others of 90 \L. Therefore,
even in the same animal (cat) there are large differences in the
data presented by different authors.


TABLE 39 Condensed


Ratois of the greatest height of the greater epithelial ridge (resp. of the inner supporting cells) according to the turns of the cochlea on age






Average age




Average body
weight




RATIOS BETWEEB TURNS




I-II




i-in




I-IV




days




grams




Line 4,778: Line 5,506:




1




5




1 :1.0




1 1.0




1 :0.9




8




11




: 1.0




1.1




: 1.2




18




21




:1.1




1.2




:1.3




213




138




:1.0




1.2




:1.3






TABLE 40






Greatest height of the greater epithelial ridge measured through the inner supporting


cells, in p. (Retzius)






RABBIT




CAT




Age


days




Basal
turn




Middle
turn




Apical
turn




Average
turn




Basal
turn




Middle
turn




Apical
turn




Average
turn




New-born




78




99




90




89




45




75




6S




63




2




60




90




90




80




Line 4,889: Line 5,674:




3




Line 4,895: Line 5,681:




G




E




D




A N




40




84




Line 4,917: Line 5,701:




7




51




68




63




61




40




54




63




52




10




36




54




56




49




Line 4,957: Line 5,755:




11




Line 4,965: Line 5,764:




fo




25 50 50 , oo 20O 3OO 4OO 5OO






Chart 7 The radial breadth of the membrana basilaris, table 9, figure 2,
distance 11.


Total radial breadth of the membrane.
50


Radial breadth of the zona pectinata.


Radial breadth of the zona arcuata.
58


After six days it is a well-known fact that the radial breadth of
the membrana basilaris is narrowest in the basal, and widest
in the apical turn (not the tip of the apex, but the beginning
of the apical turn). These differences are not always the same
between all the turns; those between I and II, and II and III
are marked; those between III and IV are small. The ratios
at 1 to 546 days show those for the upper turn to be largest,
while from 12 to 546, and 20 to 546 days the ratios in all turns
are about 1:1.1.


66




42
58




14


ANATOMICAL AND PHYSIOLOGICAL STUDIES ON


51




I
51




51


I


*
51






m


-S




Line 5,021: Line 5,806:




Ml


H a <
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H g


30


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i 1




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30


.




45


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45


B


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go




*O5O5CDr-lO5lO<r>^CO5^(NO
Gottstein ('72) thinks that the greater epithelial ridge does
not diminish its height for some time after birth, but through
the outward development of the labium tympanicum, and in
addition to this through the growth of the labium vestibulare,
the sulcus spiralis internus arises. He does not give measurements.




O
His idea was strongly opposed by Bottcher ( 72) and my results
1 1
are also opposed to Gottstein's view.


===8. The radial distance between the labium vestibulare and the habenula perforata===


i 1
The purpose of this measurement is to
rH
determine how the habenula perforata stands in relation to its
surroundings during the development of the cochlea. The measurements of this distance is difficult. During the earlier stages,
the labium vestibulare is quite undeveloped, especially in the
upper turns. At birth we see on the inner surface of the greater
epithelial ridge a small prominence under which the epithelial
cells are short and pressed together so that the nuclei seem to be
arranged in several rows (fig. 4). This appearance is due to the
invasion of the subjacent connective tissue into the epithelium.


Thus the vestibular lip arises. We do not see a furrow at this
time and cannot use the top of the furrow as a point for measuring
as did Hensen ('63) in the ox and Bottcher ('69); in the embryo cat). To the measure the distance between the insertion of
Reissner's membrane and the habenula perforata has no meaning
for my purpose, because the length of the limbus laminae spiralis
changes with age.


Thus I have measured the distance between the small epithelial
prominence on the axial side of the greater ridge, corresponding
to the edge of the labium vestibulare, and the habenula perforata.


rH
In table 41 (charts 17 and 18) are given the -values of the radial
distance between the labium vestibulare and the habenula
perforata. At the foot of the last column are given the ratios
from 1 to 546, 9 to 546, and 20 to 546 days. As we see, the
values are a little bit smaller at the earlier stage. After nine
days they are almost the same in every stage. The small differences at the earlier and later stages are probably due to the
retarded development of the labium vestibulare.


When we consider the values for this distance in each turn,
it is evident that these increase from base to apex. In the condensed table 42 this relation is shown.


CO CO
Hensen ('63) finds that the distance from the top of the furrow
to the habenula perforata is in the fetal calf and in the ox the. same, 255 [x. He considers the holes of the habenula as a ' punctum
fixum. ' Bottcher ('69, 72) agrees with Hensen and gets in the
cat embryo and the adult cat the following values (table 43).


i-H 1 1
TABLE 41


Radial distance between the labium veslibulare and the habenula perforata on age


(charts 17 and 18)






AGE


N


BODY WEIGHT




TURNS OP THE COCHLEA M


i-H


I




II




III




IV




Average




days


119 a
a g


X
grams


5




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108




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257




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105




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366




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1
255


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79


4*
71


105




143




150


9)1


H2
119


o^




<D-*<NO5CO<NCOl>?OO5i-H(NCi'-<
Ratios 1 546 days
(MiO?C>COCCDCOCDcOl>t^l>.OO


9546 "
20546 "


*


l-H


1.0
1.0
1.0


(N


rH


TABLE 42 Condensed


rH
rH




s
Ratios of the radial distance between the labium vestibulare and the habenula
perforata according to turns of the cochlea


Sioco^




Line 5,468: Line 6,257:




H g
RATIOS BETWEEN TURNS




AVEKAGE AGE




i-H
WEIGHT




I-II




I-II I




03 "" ^ ^
I-IV


V


days




grams








K a


M "


S S5
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1.3
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1.6




1.8




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Comparing the results of both Hensen and Bottcher with
my own, the values obtained by Hensen are large, as would
be expected in the larger animal. The cat and rat however,
give similar values. We conclude, therefore, that broadly speaking, the habenula perforata is to be considered as a 'punctum fixurn, 'at least after birth.


T 1
===9. The radial distance between the labium vestibulare and the inner edge of the head of the inner pillar cell===


rH
To measure the




J3


o
140


IS 00
00 t>


-J


c3
120






1OO


BODY




H
AGE DAYS


M


S
25


S


if


50


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on
Chart 17 The radial distance between labium vestibulare and the habenula
perforata, table 41, figure 10.






Chart 18 The radial distance between labium vestibulare and the habenula
perforata according to the turns of the cochlea, table 41.


radial breadth from the labium vestibulare to the inner edge
of the head of the inner pillar cell, I have used, at earlier stages,
as in the preceding chapter, the same small prominence as an
inner fixed point (fig. 4). In table 44 (chart 19) are given the
values for this radial distance according to age. At the bottom
of the last column are given the ratios from 1 to 9, 1 to 546




hi


2
TABLE 43
"o


>,rH
Distance between labium vestibulare and habenula perforata in n (Bottcher)


03
T3


e


PLACE OF




CAT EMBRYO 9 CM.


1


CAT EMBRYO 11 .5




p
CAT THREE DAYS


4


ADULT CAT


L i-l CO D 3> 04 *Q 'O lO'Q O Q b D <D


t-li-H<NiMiOOiOiOO'* 1
MEASUREMENT
-i T-I (N CO U5




03
LONG
tn ^3


Is


?
CM. LONG


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OLD


CO


-f
o


n


i-H
I turn




20-546 "
120




1 A nil
120


Right side
Left side
Average


120




GROWTH OF THE INNER EAR OF ALBINO RAT
100




II turn


43


130




In the zona arcuata (inner zone) the same relation is to be
130
seen in each turn; therefore, in the early period the breadth
is less in turn IV than in the other turns. Very soon, however,
the value in turn IV becomes the largest and diminishes toward
the base. The rate of the growth of this zone, from 1 to 546 days,
is also smallest in turn I, and largest in turns III or IV; the
ratios being in the first 1:1.6, and in the last 1:2.1.


In the zona pectinata (outer zone) we see also similar relations.


TABLE 11
130


Ratios of the radial breadth of the membrana basilaris according to the turns of the


cochlea on age
110




III turn


AGE


150


BOOT WEIGHT


140


Ratios between turns


140


I-II


130


I-III




I-IV
TABLE 44




days


Radial distance between the labium veslibulare and the inner edge of the head of the
inner pillar cell on age (chart 19)


gms.




AGE




BODY WEIGHT




TURNS OF THE COCHLEA M




1
I




5
II




1
ill




1.0
IV




1
Average




1.0
days




1
grams




1.0




3




8








1.0




1




1.0
5




111




1.0
126




6
138




11
130




126




1.1
3




8




1.2
84




118




1.2
150




9
170




10
131




6




1.1
11




88




1.2
119




159




1.1
180




12
136




13
9




10




1.2
94




131




1.3
168




179




1.3
143




15
12




Line 5,832: Line 6,606:




69




1.1
97




138




1.3
156




115




1.3
15




20
13!




29
",' 66
 
 
103
 
 
137
 
 
149
 
 
114
 
 
20




29




1.1
66




103




1.2
137




148




1.3
114




Line 5,874: Line 6,669:




65




1.2
100




136




1.3
148




 
112
 
1.3




Line 5,895: Line 6,690:




61




1.1
98




129




1.3
144




 
108
 
1.3




Line 5,916: Line 6,711:




64




1.1
99




139




1.3
153
 




 
114
1.3




Line 5,937: Line 6,732:




60




1.1
99




129




1.2
143




 
108
 
1.3




Line 5,958: Line 6,753:




67




1.1
100




134




1.2
149




 
113
 
1.3




Line 5,979: Line 6,774:




60




1.1
102




130




1.2
151




 
111
 
1.3




Line 6,000: Line 6,795:




55 :..




1.1
99




128




1.2
143




106




1.3


Ratios 1 9 days


1546 "
12546 "


Only slight differences in the ratios according to age are found.


In table 11 the ratios according to the turns of the cochlea
are given. While from one to three days the ratios are the same
in each turn, 1:1.0, yet after six days those for turns I to II are
smallest, and for I to IV larger, thus showing slight differences
between them.


In the literature we find only one description, that by Retzius
1.1
('84) touching the growth of the radial breadth of the membrana
basilaris according to age. He measured this membrane in the
rabbit and cat and got the following values in n (table 12).  


0.8
0.9




44


TABLE 45 Condensed




ANATOMICAL AND PHYSIOLOGICAL STUDIES ON


Ratios of the radial distance between the habenula perforata and the inner edge of


the head of the inner pillar cell according to the turns of


Comparing these values with mine obtained for the albino
the cochlea on age  
rat, it is to be noted that those of Retzius are generally larger
than those for the albino. For example, while I get at birth
only 126 (x in the basal turn, Retzius ('84) obtains 180 [x in the
rabbit and even 270 [x in the cat. As stated above, the radial
breadth increases in the albino rat continuously with age. It
is very peculiar to find in the Retzius table that the breadth
of the membrane in the cat is decidedly larger at birth than at
three and seven days. The average value for the new-born is
315 [x, which is larger than at thirty days, which is 310 [x.


Retzius ' data show the membrane in the rabbit and cat always
wider in the apical than in the basal turn at birth and at two


TABLE 12
Breadth of membrana basilaris according to turns, p. (From Retzius, '84}






RABBIT




CAT
KATIOS BETWEEN TURNS




Age
AVERAGE AGE




Basal
WEIGHT




Middle




Apical




Basal




Middle




Apical




days
I-II




I-HI




I-IV




days




grams




Line 6,100: Line 6,879:




New-born




180
1




270
5




1 1.1




1 \.9


270


1 1.2


300


6


375


10


2


1.4


220


1.8


272


2.0


280


154




102




1.5




2.1




2.3




3
and 12 to 546 days of age. As the table shows, the values increase in general from birth to nine days; therefore, the surface
of the greater epithelial thickening from the labium vestibulare
to its outer boundary becomes, during the earlier stage, wider
and wider, then decreases sharply, and after that continuously
but slowly. This sudden diminishing of the distance has a very
intimate relation with the change in the form of the papilla
spiralis at this stage of development.


This point I will discuss later.


That the values increase from the base to the apex first rapidly
and later less rapidly, is also to be seen here. Table 45 shows this
relation clearly. It is remarkable, however, that the ratio becomes






'''Chart 19''' The radial distance between the labium vestibulare and the
inner edge of the head of the inner pillar cell, table 44.


at each turn larger with age, although the absolute value is
after nine days generally smaller than at the preceding age.
Therefore, we see that the diminution of the distance after
nine days is largest in the basal turn and smallest in the apical.
Hensen ('63) asserts that there is a movement axialward of
the organ of Corti (resp. the head of the pillar cell), but gives no
measurements. Neither Bottcher nor Retzius measured this
distance. Prentiss ('13, page 445) states that "the distance
between the inner angle of the cochlea and the pillar cells, two
definite points, may be measured with considerable accuracy
and shows no important change in the position of the spiral
organ from the 13 cm. to the 18.5 cm. stage, nor later in the
new born animal" (pig) But he also does not record his measurements.




.  
Hardesty ('15, p. 54) says "that the space occupied by the
width of the greater epithelial ridge increases throughout the
coils of the cochlea up to pigs of 15 to 16 cm., and thereafter
it begins to decrease very perceptibly." He measured the
width ''from the membrana propria of the epithelium of the
greater ridge, at its most axial extension under Huschke's teeth,
to the apical end of the inner hair cell of the spiral organ. " The


TABLE 46


200
Vertical distance from the membrana basilaris to the surface of the pillar cells on


age (chart 20}


280




Line 6,163: Line 6,979:




7


TURNS OF THE COCHLEA M


270


AGE


306


BODY WEIGHT








211




258




300
I




10
II




255
ill




310
IV




390
Average




days




grams




Line 6,205: Line 7,021:




11




Line 6,211: Line 7,026:




1




5




35




255
36




300
39




330
36




14
37




300
3




360
8




410
30




29




29




29




29




6


30


11




29




32




31




29




240
30




300
9




390
10




32


days. My results, given in table 10, show the reverse at the
ages of one and three days. This is an expression of greater
immaturity in the case of the rat.


In comparisons like the foregoing, several conditions must
33
be kept constantly in view.


So far as absolute values are concerned, it is to be expected
that these would be unlike in the different mammals, because
the cochleas differ in size. As to the relations between the values
at birth and at maturity, it is plain that these cannot be expected to agree unless the cochleas of the animals compared
are in the same phase of development at birth. In the foregoing
instances it appears that the cat is relatively precocious, as
compared with the rabbit, while, as might be expected, because


35




GROWTH OF THE INNER EAR OF ALBINO RAT
36




34


45


12




of their closer zoological relationship, the rat and the rabbit are
13
in better agreement, although the rabbit appears to be a trifle
more advanced at birth than the rat.


Finally, in the comparison of different series of data, differences due to the lack of homogeneity in the series of animals
used and to the various techniques employed can hardly fail to
play an important part, and allowance must be made for these
disturbing factors.


When we consider the rate of growth, the ratio of a one to a
41
fourteen-day-old rabbit is 1:1.6, according to Retzius; therefore,


TABLE 13
Breadth of basilar membrane


45




ANIMAL
50
AUTHOR




TURN IN WHICH MEASUREMENT WAS MADE IN M
52




Basal
47




Second
15




Third
13




Fourth
44




Average
48




Man-New-born
53




57




51




20




29




53




Hensen ('63)
57




235
67




413
71




62




495
25




381
36




Man Mature
55




56




66




68




61




50




Retzius ('84)
59




210
53




55




340
67




360
68




303
61




Calf
100




112




53




54




64




67




Kolmer ('07)
60




200
150




280
183




52




400
54




293
63




Pig
66




59




257




137




53




56




Kolmer ('07)
63




168
69




200
60




256
366




304
181




232
51




Goat
56




66




67




60




546




255




Kolmer ('07)
52




124
55




384
62




432
66




59




313
Ratios 1 12 days 1-1.3




Cat
1 20 " 1.7




1546 " 1.6




12546 " 13




20546 " 1.0






method of measurement differs from mine, so the results cannot
be compared directly. While the distance in the rat increases
to nine days of age, that in the pig decreases perceptibly in
fetuses more than 16 cm. long.


According to Hardesty ('15, p. 55). "the decrease in the I
and III half turns may be as much as one-third of the width
of the greater ridge when at its maximum size and activity. "
And "after the tectorial membrane is about completely produced,




Bottcher ('69)


GROWTH OF THE INNER EAR OF ALBINO RAT


90




75




435


and while the spiral organ is enlarging, the inner hair cells, and
therefore the organ, may be moved in the apical coil of the
cochlea axialward a distance of about half the maximum width of the greater epithelial ridge, "


The differences of the values in the rat at 9 and 546 days are
in the basal and apical turn about the same, 39 and 36 n, respectively (table 44). Thus while the inner edge of the inner
pillar cell approaches at 546 days in the basal turn by as much
as 41 per cent of the distance present at nine days, that in the apex moves only 20 per cent inward in old age. This result
is the reverse of that obtained in the pig by Hardesty. The
reason for this contradiction I will discuss later.




263
'''Chart 20''' The vertical distance from the membrana basilaris to the surface
of the pillar cells, table 46, figure 1, 1-1.




Cat


===10. The vertical distance from the membrane basilaris to the summit of the pillar cells===


The method of getting the vertical
distance from the membrana basilaris to the surface of the
pillar cells is shown in figure 1, line 1-1. In table 46 (chart 20)
are given the values thus obtained. At the foot of the last
column are given the ratios of this distance at 1 to 12, 1 to 20,
1 to 546, 12 to 546, and 20 to 546 days. The average value is
relatively large at birth, it diminishes at three days, then increases
more rapidly to twenty days. After this it decreases very slowly.
The maximum height of the arch of Corti is at twenty days of age. Comparing the values for the height in each turn, we find
that from nine days they increase from the basal to the apical
turn. This relation can be easily seen in table 47.


Retzius ( '84) gives in the rabbit and cat the following values
(table 48).






TABLE 47 Condensed






Ratios of the vertical distance from the membrana basilaris to the surface of the
pillar cells according to the turns of the cochlea






Middendorp ('67)








RATIOS BETWEEN TURNS








AVERAGE BODY




246-275




AVERAGE AGE


it has very nearly the value found in the albino. In the cat,
however, the ratio between one and thirty days is 1:0.97; therefore, it apparently decreases a bit.


This difference is most readily explained as due to the
WEIGHT
precocious development in the cat at birth.


On comparing the radial breadth of the membrane obtained
from several mammals by various authors, we find the following
values (table 13).


The values here given must be read in the light of the various
modifying conditions to which reference has just been made.






46 ANATOMICAL AND PHYSIOLOGICAL STUDIES ON


My average value after twenty days is 199 [i; therefore, it
is absolutely the smallest in this series of mammals. The rat
is also the smallest species examined.


As shown in the literature quoted, and also in my own results,
the membrane increases in its breadth in all the mammals examined from the base toward the apex a relation contrary to
that reported by the older authors (Corti, '51, and others).
This increase is continuous, but is at first more rapid and afterwards more gradual. The ratios of this increase in the albino
rat are given in table 11.


The next question relates to the breadth of each zone of the
membrane according to age. So far as I know, there is no such
study in the literature, not even in Retzius. In the albino rat,
as shown in table 9, each zone increases in breadth with age.
The rate of growth, however, is somewhat different, and in the
zona arcuata it is greater than in the zona pectinata (1:1.9 and
1 :1.5, respectively), although the absolute value is always greater
in the latter.


As noted above, the membrane increases in its radial breadth
from the basal to the apical turn. How, and in which portion
of the membrane does this increase arise? Henle ('66) first
regarded the breadth of the inner (zona arcuata) as approximately constant.


"Nicht nur in den verschiedenen Regionen einer Schnecke,
sondern, soviel ich sehe, selbst in den Sshnecken verscheidener
Tiere und des Menschen; sie schwankt nur wenig um 0.01 mm."
(Eingeweidelehre des Menschen, 1866, S. 793).


In the second edition of his book ('73) he states, however,
that in the increase of the breadth according to the turn, both
zones seem to take part. Hensen ('63) gets in the zona arcuata
of the base of the human cochlea the breadth of 19 ^ and in the
apex 85 \L. Middendorp ( '68) gives in the cochlea of the cat a
continuous increase of the breadth of the zona arcuata from 94
to 122.5 {A. ."''"'


More detailed data are given in table 14.
I-II


According to all these authors, the breadth of both the inner
and outer zones increases from base toward apex and results


i-ni




GROWTH OF THE INNER EAR OF ALBINO RAT
I-IV




days


47


grams




in the increase of the total radial breadth of the membrane
according to turn. My results obtained from the albino rat
agree with these data.


3. Radial distance between the habenula perforata and the
inner corner of the inner pillar cells at base. The measurements
of the radial distance from the habenula perforata to the bases of
the inner and outer pillar cells were taken to determine their
postnatal growth. As already stated, the cells from which the
arch of Corti arises stand at birth nearly vertically and have no
space between them (fig. 4). In the adult, however (fig. 10),
we see a space, the tunnel of Corti lying between them and
changes in the form of the arch occur. To follow these changes


TABLE 14
Breadth of the inner zone of the membrana baeilaria in n








1


NUMBER Of TURN


5




1 :1.0


First


1 : 1.1


Second


1 : 1.0


Third


1


Fourth


11


Cat-adult


: 1.1




: 1.1




: 1.1




18




21


Bottcher ('69)


: 1.1


60


: 1.2


105


: 1.3


135


213




138


Guinea-pig


: 1.0




: 1.2




: 1.3






TABLE 48
Vertical distance from the membrana basilaris to the summit of the pillar cells




Winiwarter (70)


BABBIT


45-52


CAT


63-68


Age


71-80


Basal


80-83
turn




Middle
turn


it seems at first necessary to study the growth of the pillar
cells and of the other elements in the organ of Corti. At the
same time we must take into consideration the inward shifting of
the organ of Corti, first studied by Hensen. This shift inward
of the organ is, according to Hensen, chiefly caused by the
wandering of the pillar cells, especially the inner pillar cell.
Therefore, it seemed necessary to determine the radial distance
of the pillar cells from the habenula perforata at different ages
before discussing this interesting problem.


In table 15 are given the values for the radial distances between
Apical
the habenula perforata and the inner corner of the inner pillar
turn  
cell at its base according to age (figs. 4 to 9). As we see, the
average value increases till three days of age, then vanishes
suddenly, though at six days we have a measurable interval
in the upper turns of the cochlea. Comparing these distances
according to the turn, they are smallest in turn I and increase




Average


48


Basal
turn




ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
Middle
turn




Apical
turn


toward the apex. In some cases, at six days, we have no interval
in the basal turn, but in the higher turns an interval gradually
appears and at the apical turn is largest. This table shows,
therefore, that the inner corner of the base of the inner pillar
cell lies at birth outward from the habenula perforata at an


TABLE 15 Condensed
Average


Radial distance between the habenula perforata and the inner corner of the inner


pillar at base on age
days






AGE
New-born




BODY
45
WEIGHT




TURNS OF THE COCHLEA M
70




I
61




II
59




ill
45




IV
60




Aver.
48




days
51




2




45




69




40




51








1




5




19




22




22




23
3




22




3




8




23




28




28




30
39




27
60




6




11




In one case 5




In 2 cases 10
7




14
46




18
60




60




55




45




47


In other 3 cases


50


In other cases


44




10




45




69


9


69


10


61




Line 6,880: Line 7,697:




11




12




13




Line 6,893: Line 7,709:




JK




50




60




42




51




14


average distance of 22 \L. At three days of age the inner corner
moves farther outward with the developing membrana basilaris
and the distance increases from the base to the apex. Between
three to six days this outward movement not only stops, but
reverses its direction, and at six days it often becomes zero in
the basal turn. Bottcher ('72) finds in the cat the following
values for this interval in \i (table 16).


TABLE 16
45




57


CAT EMBRYO 11 CM. LONG


66


ADULT CAT


56


I




II




ill




IV




Average




I




II


30


ill




IV




Average




15




39




30
' }'




30
33




29
51




3
57




3
47




3


Table 48 shows that the height of the arch of Corti in the
rabbit approximates that in the rat, though there are considerable
differences in the earlier stages. In the former the arch of Corti
develops after: birth only a little, and is therefore more precocious than in the rat. In the cat the same relation is to be
seen, but the absolute values in the latter animal are smaller
than in either the rabbit or the rat.


3




3
===11. The greatest height of the tunnel of Corti===


Some authors have reported in several animals the appearance of the tunnel
of Corti just after birth, or even in later intrauterine life. In
the rat, however, it first appears through all the turns after
the ninth day. Sometimes we see it at nine days in the lower
turn, though not yet in the upper. The method of measuring
the height is shown in figure 1, line 1-1'. Table 49 (charts 21
and 22) gives the values for the greatest height of the tunnel of
Corti. At the foot of the last column are given the ratios from
12 to 25, 12 to 546, and 25 to 546 days.


As the table shows, the space appears in all the turns at twelve
days and has considerable height. This increases to twenty-five
days, than decreases very slowly. This increase and decrease
correspond to the changes in the distance of the summit of the
pillar cells from the basilar membrane.


TABLE 17
When we consider the height in each coil of the cochlea, we
find the value increases from the base to the apex, first rapidly
then slowly. In table 50 this relation is clearly shown.


Retzius ('84) gives the values for the adult rabbit, man and
cat (one month) as follows (table 51).


According to this table, the average height is in the adult
man, cat, and rabbit somewhat less than in the rat.


BABBIT
===12. The height of the papilla spiralis at the third series of the outer hair cells===


The measurements were taken along the
line 2-2 shown in figure 1. The growth of this vertical height
depends not only upon the increase of the length of the corresponding outer hair cell, but chiefly upon the development of
the Deiters' cells, especially of the outermost row, and of the
sustentacular cells of Hensen.


CAT
In table 52 (charts 23 and 24) are given the values for this
vertical height of the papilla spiralis at the third series of the
outer hair cells according to age. At the bottom of the last
column are the ratios at 1 to 12, 1 to 20, 1 to 546, and 20 to 546
days. The heights decrease at three days, but increase from
nine to twelve days very rapidly, nearly doubling their minimal
values, and reach a maximum at twenty days. After that time
they decrease very gradually to the end of the record. Therefore, the difference between the ratios at 1 to 20 and 1 to 546
days is very small.


{{Wada1923 table49}}


AGE




Basal
{{Wada1923 table50}}
turn


{{Wada1923 table51}}


Middle




Apical
At twelve days and after, the values for the height increase in
passing from the base to the apex, at first rapidly, then more
slowly. In the earlier stages this relation is obscure or reversed.




Average




Basal
'''Chart 21''' The greatest height of the tunnel of Corti, table 49, figure 1, 1-1




Middle


'''Chart 22''' The greatest height of the tunnel of Corti, according to the turns
of the cochlea, table 49.


Apical
In the condensed table 53 are given the ratios in each turn.
While the ratio of each turn before eight days is about 1:1.1,
and between turns I and II remains constant in the later age,
that for I to III and I to IV is at 18 and 213 days decidedly
larger. Therefore, the increase of the height is most marked
in the III and IV turn, as shown in chart 24.




Average
{{Wada1923 table52}}




days
{{Wada1923 table53}}




TABLE 54
Height of the papilla spiralis at the third scries of outer hair cells in n (Retzius)






BABBIT




CAT




AGE




Basal
turn




Middle
turn




Apical
turn




Average


New-born


Basal
turn


300


Middle
turn


300


Apical
turn


300


Average


300


days


5




40




45




30




2




10




12




30




17


New-born




48




70




60




59




45




60


3


45




50




2




45




70




54




56


3




36




Line 7,121: Line 7,987:




7






3




Line 7,139: Line 8,005:




40




58




Line 7,148: Line 8,016:




11


7




54




69




66




63




42




5<




48




49




10


18


42




86




84


GROWTH OF THE INNER EAR OF ALBINO RAT 49


Retzius ('84) studied this distance in the rabbit and cat and
71
gets the values given in Table 17.


Comparing the values of these two authors with my own,
there are of course some differences. While in the rabbit the
interval is large at one day, it is greatly diminished at two days
of age. At three days the inner corner of the cell reaches the
habenula perforata. In the cat the values are nearer to mine.
The fact that the values increase from base toward apex is to
be seen here also. This peculiar phenomenon appears, therefore
not only in the albino rat, but also in the rabbit and the cat
during the earliest stage of postnatal life.


4- The radial distance between the habenula perforata and the
outer corner of the inner pillar cell (resp. the inner corner of the
outer pillar cell) at base. This measurement is difficult. As we
know, the inner and outer pillar cells in the albino are from birth
till nine days of age in contact with each other along their whole
length, and therefore they do not yet surround the space forming
the tunnel of Corti. At about nine days, however, the tunnel
appears while the cells remain in contact by their bases. It
is almost impossible to determine the line of contact on the
basilar membrane in my preparations. To get the radial distance
between the habenula perforata and the outer corner of the inner
pillar cell I have proceeded therefore as follows:


First, I have measured this distance directly up to nine days
of age; after that this distance consists of the sum of the radial
basal breadth of the inner pillar (not pillar cell) and the breadth
of the inner basal cell on the basilar membrane. Since it is
impossible to get the latter value directly in my sections, I
considered that half of the radial distance between the outer
corner of the inner pillar and the inner corner of the outer pillar
would be equivalent to it.


Of course, I do not know whether the value of the sum of
these two distances is at all ages, identical with the distance
between the habenula perforata and the outer corner of the inner
pillar cell at its base. I believe, however, that a systematic
study of the growth of this distance will be significant.






50






ANATOMICAL AND PHYSIOLOGICAL STUDIES ON






In table 18 are given the values for the radial distance between
the habenula perforata and the outer corner of the inner pillar
at base up to nine days of age. As shown, these values, on the
average, increase with age. The increase of this distance means
that the base of the inner pillar cell spreads outward more and
more.


When we consider this distance according to the coil of the
11
cochlea, it is at birth about the same through all the turns
(table 18; at three days it increases up to turn III, and in turn


TABLE 18


Radial distance between the habenula perforata and the outer corner of the inner


pillar at base on age




Line 7,252: Line 8,082:




TURNS OF COCHLEA M




AGE




BODY WEIGHT
60




I
72




II
42




III
58




VI
14




Average
60




days
87




grams
90




79




Line 7,292: Line 8,121:




1




5




40
30




41




39




39




40




3




8




48
36




49
57




50
70




48
54




48


80


6




11
GROWTH OF THE INNER EAR OF ALBINO RAT




38


81


45




58
Retzius ('84) finds in the rabbit and cat the [values for this
height given in (table 54).


Comparing these average numbers with mine, it appears that
the height in the rabbit is greater, and in the cat smaller than


53




49
u
 
 
9
 


70
5O
30
10  
10  




44


k


46




56
AGE




53


o


50




25 5O 50 |OO 2OO 3OO 40O 5OO


IV the value is the same at the apex as at the base. At six days
the value in turn III is also largest, and next largest in turn IV.
At nine days of age the same relations are to be seen.


In table 19 (chart 8) are given the values for the radial basal
breadth of the inner pillar (not pillar cell) on age. At the bottom
of the last column are the ratios from 6 to 546, and 20 to 546
days. As above noted, the rod can be followed at birth from
the upper part to near the base of the cell (fig. 4). At three days
(fig. 5), its base reaches the basilar membrane as a thin and slender
thread, but we cannot measure its basal breadth accurately.
During the next few days it increases in radial breadth rapidly,
and at six days has the average value of 29 [/. (table 19). After
nine days it decreases distinctly till twenty days, after which
the value remains nearly constant. These relations are evident
in the ratios. While the breadth at six days is about twice
that at 546 days, that at twenty days has the same value.


Chart 23 The height of the papilla spiralis at the third series of the outer
hair cells, table 52, figure 1, 2-2.




GROWTH OF THE INNER EAR OF ALBINO RAT


90




51


70




According to the turn of the cochlea, the values from nine
to fifteen days become gradually larger on passing from the
base toward the apex. After twenty days, however, this relation
vanishes, and the values become nearly the same through all


TABLE 19
50
Radial basal breadth of the inner pillar on age (chart 8)






day*
30


1


3


ti
10


9


12


15


20
AGE DA.YS


25


50
O


100


150


257
25


366


546


Ratios 6
50
20






WEIOHT
5O 1OO 2OO 3OO 4OO 5OO
BODY




TURNS OF THE COCHLEA M


Chart 24 The height of the papilla spiralis at the third series of the outer
hair cells, according to the turns of the cochlea, table 52.


I
in the rat. In both animals the values increase rapidly at ten
to eleven days of age, as in the albino rat, but the height in these
animals is at the earlier stage almost twice as large as in the rat.
Hardesty ('15) measured the thickness of the organ of Corti in




II


82


III




IV
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON




Average


the pig in a somewhat different way, using the vertical line from
the basilar membrane proper through the m'ddle of the outer
hair cell to the surface of the organ, and found the increase in
thickness to take place most rapidly at the stages before full term,
though it seems to continue after birth. I have not made cor
TABLE 55


grams
Greatest height of Hensen's supporting cells on age (chart 25)






AGE




BODY WEIGHT




TURNS OP THE COCHLEA M




1




II


5


III




IV




Average




days




grams




Line 7,503: Line 8,308:




8








I




5




36




36




38




31




35


11


3


29


8


31


18


27


21


27


21


29


24


10


21


28


6


28


11


33


21


35


20


31


 
21
13




Line 7,563: Line 8,372:




19
20




22
9




25
10




21
20




13
23




18
23




18
24




19
23




19
12




19
13




29
40




14
49




15
56




15
58




15
51




Line 7,611: Line 8,420:




36
13




14
44




15
56




14
69




15
72




15
60




59
20




14
29




14
64




14
64




13
86




14
87




112
75




14
25




14
36




14
69




13
71




14
84




183
86




15
78




15
50




15
59




15
71




15
74




137
87




15
89




15
81




15
100




15
112




15
77




181
. 78




16
87




17
89




15
83




15
150




16
183




255
76




15
77




14
<3




16
93


85


15
257




15
137




-546 days
81




83




89




89




86




1 :0.5
366




-546 "
181




82




83




89




91




: l.o
86
 
 
 
40
U
20
 
n
 
 
 




546




255




79




79




92




93




86






Ratios 1 6 days


1 12


1 20


1546


6 12


6 20


6546
12 20
12546
20546






0.6
1.5
2.1
2.5
2.6
3.8
4.3
1.5
1.7
1.1






responding studies on the rat. In the latter animal, however,
the rapid increase usually appears at twelve days of age, when
the animal as a rule first responds to auditory stimuli, and thus
we have a correlation between the development of the organ
and the beginning of the function, which will be discussed later.
In the case of one rat that could hear at nine days this change
had already occurred.


===13. The greatest height of Hensen's supporting cells===


The older authors (Kolliker and others) thought that the arch of Corti
marks the highest point of the papilla which slopes from this
point gradually outward to the cells of the zona pectinata.
Against this erroneous idea Hensen ('63) first published observations showing that the highest point is in the papilla which
ascends laterally from the outer hair cells, and then slopes
abruptly and passes over to the cells of the sulcus spiralis externus.
We term this prominence Hensen's prominence and the cells,
Hensen's supporting cells. The measurements of the height of these cells were made along 3 3 in figure 1. Table 55 (chart
25) shows the values for the greatest vertical height of these
supporting cells according to age. At the foot of the last column
are given the ratios from 1 to 6, 1 to 12, 1 to 20, 1 to 546, 6 to 12,
6 to 20, 6 to 546, 12 to 20, 12 to 546, and 20 to 546 days. The
values diminish at the earlier stage from birth to six or nine days.
At twelve days they increase suddenly, more than doubling.
After that they increase to old age, rapidly up to twenty days
and then slowly. Here also the height increases from the base
to the apex, the most marked increase occurring between turns
II and III. In table 56 this relation is clearly shown. Retzius
('84) gets values of this height in the rabbit and cat as follows
(table 57).






'''Chart 25''' The greatest height of Hensen's supporting cells, table 55.




In both the rabbit and the cat the height increases at ten to
eleven days very considerably, as it does in the rat. Only
there is a large difference in the absolute values for the
three animals, these being largest in the rabbit and smallest
in the cat. The final average values in the cat are nearly the
same as those in the rat at the same age.


Kolmer ('07) finds in the calf the value in the highest point
of the organ of Corti in the region of the innermost Hensen's
cells as follows:


In the basal turn, 84 [A


In the second turn, 90 JJL


In the third turn, 105 [JL


Average, 93 [i.


Hensen ('63) gives in man the average height of the papilla
as 90 (JL in the hamulus and 60 [j. in the radix. Thus the height
of Hensen's cells is different in different animals.


When we consider the growth in the height of Hensen's cells
we can picture the change of the form in the papilla spiralis.
As shown already, the height of the pillar cells is largest at the
earlier stage, when the papilla has its highest point at the summit
of the arch of Corti, and slopes downward to the Hensen's cells.
But at twelve days the form is reversed, and the highest point
is in Hensen's prominence from which the surface slopes inward
more or less steeply to the surface of the pillar cells and the
inner supporting cells. Thus the surface of the papilla does
not run parallel to the basilar membrane, but makes with it a
sharp angle opening outward. This angle has been measured.


===14. The angle subtended by the extension of the surface of the lamina relicularis with the extended plane of the membrana basilaris===




As just stated, the lamina reticularis after the earlier stages
is not parallel to the membrana basilaris, but forms an angle
with it. The measurements of this angle , were taken as
shown in lines 4~4' i n figure 1. In table 58 (chart 26) are given
the values for the angle in degrees. Before nine days there is
no appreciable angle. From twelve to twenty days the angle
increases rather rapidly, and after twenty days continuously
but slowly. The ratio at the bottom of the last column shows
this clearly.


Comparing the values of the angle in each turn according to
age, there is no clear evidence that it increases from base to apex,
though it tends to be largest in turn III and next largest in turn
II. The condensed table 59 shows these relations. Retzius
( ; 84) finds this angle in the rabbit and cat to be as in table 60.


TABLE 56 Condensed


Ratios of the greatest height of Hensen's supporting cells according to the turns of the cochlea






RATIOS BETWEEN SUCCESSIVE TURNS




AVERAGE AGE




AVERAGE BODY




Line 7,836: Line 8,746:




WEIGHT




1




Line 7,846: Line 8,758:




I-II




I-III




I-IV




days




grams




Line 7,862: Line 8,779:




1




5




1 1.0




1 1.1




1 0.9




8




11




1.1




1.2




1.2




18




21




1.1




1.4




1.5




213




138




1.0




1.2




1.2






TABLE 57
Greatest height of Hensen's supporting cells in M (Retzius)






RABBIT




CAT




Age
Days




Basal
turn




Middle




Apical




Average




Basal




Middle




Apical




Average




Xew-born




38?




60?




50?




49?




45




50




39




45




2




55?




60?




Line 7,970: Line 8,934:




3




Line 7,984: Line 8,949:




39




54




Line 7,994: Line 8,961:




7




48




81




67




65




57




50




40




49




10




105




125




105




112




Line 8,034: Line 9,015:




11




Line 8,041: Line 9,023:




"




Line 8,049: Line 9,030:




75




78




45




66




14




Line 8,062: Line 9,048:




150




120




Line 8,081: Line 9,069:




30




Line 8,095: Line 9,084:




50




69




95




71






Retzius also finds in man in the basal turn 25, in the middle
35, and in the apical 23. Thus the angle always increases with
age, but has different absolute values in different mammals and
always tends to be greater in the middle turns.


15. Lengths of the inner and outer pillar cells. The measurements of length were taken as shown by lines 1-1, and 2-2 as in
figure 2. This does not give the total length, but the length
from the base to the point, just below the joint. As is well






TABLE 58


Angle of the lamina reticularis with the plane of Ihe membrana basilaris in


degrees, 6 (chart 26}




Line 8,119: Line 9,122:




TURNS OF THE COCHLEA DEGREES




AGE




BODY WEIGHT




Line 8,133: Line 9,139:




I




Line 8,149: Line 9,156:




II




III




IV




Average




days




grams




Line 8,171: Line 9,184:




1




5




Line 8,178: Line 9,193:




\




Line 8,191: Line 9,205:




3




8




Line 8,210: Line 9,226:




6




11




Line 8,229: Line 9,247:




9




10




Line 8,248: Line 9,268:




12




13




7




12




13




9




10




15




13




11




14




13




13




13




20




29




15




13




11




11




13




25




36




14




14




13




13




14




50




59




15




15




17




11




15




100




112




15




14




16




14




15




150




183




15




15




19




17




17




257




137




13




15




18




17


Ab


16




366


DA'


181


/q


16




15




16




16




16




546




255




16




16




17




17




17




Vertical averages








13.7




14.3




15.3




13.8




Line 8,406: Line 9,498:




Ratios 12 20 days 1 : 1.3


12546 " :1.7


TABLE 59 Condensed


Ratios of the angle of the lamina reticularis with the plane of the membrana basilaris
according to the turns of the cochlea




Line 8,418: Line 9,515:




RATIOS BETWEEN TURNS




AVERAGE AGE




a
AVERVGE BODY
WEIGHT




I-II


25 5O 5Q IOO 20O 3OO 4OO 5OO


ChartS. The radial basal breadth of the inner pillar (not pillar cell),
table 19, figure '2, distance 3.


the turns. In table 20 the ratios of the turns I to II, I to III,
and I to IV are given for three age groups (condensed from table


I-II I




52
I- IV




days
12


ANATOMICAL AND PHYSIOLOGICAL STUDIES ON


grams
13




From the data given by Retzius ('84) we get the values in jx
1 1.7
of the radial basal breadth of the inner pillar in the rabbit and
cat as follows (table 21).  


Comparing these values with my own, it is to be noted that
Retzius' measurements in the rabbit agree perfectly at the
earliest stage with those in the albino rat. Also we find in the


1 1.9




TABLE 20 Condensed
1 : 1.3




18


Ratios of the radial basal breadth of the inner pillar according to the turns of the


cochlea on age
21




1.0




0.9




:0.9


RATIOS


213


BETWEEN TTTBN8


138




1.0


AGE


1.2


BODY WEIGHT


:1.0


I-II




I-III
TABLE 60


Angle of the lamina reticutaris with the plane of the membrana basilaris in degrees


I-IV
(Retzius)




days


Age


grams


Basal
turn




Middle
turn




Apical
turn




Average


8


Basal
turn


11


Middle
turn


1 1.0


Apical
turn


1 1.0


Average


1 1.1


days


14




13




1.1




1.2




1.3




189




124




1.0




1.0


New-born


1.0






TABLE 21


Radial basal breadth of inner pillar in n (Retzius)
5?




8?


BABBIT




CAT




Age




Basal
turn




Middle




Apical
5? 8?




Average




Basal


2


Middle




Apical




Average




days




Line 8,608: Line 9,697:




New-born


3




Line 8,623: Line 9,712:




11








5? 8?




Line 8,635: Line 9,724:




2


7




17




19




11




Line 8,648: Line 9,740:




5




5




10




Line 8,657: Line 9,752:




10




20




30


3


23




24




Line 8,677: Line 9,776:




12






11




Line 8,689: Line 9,788:




7




15




12




15
20




14
1020




10




15








14




25




10
50




17
45




18
40




18




18




Line 8,739: Line 9,833:




30








11




Line 8,754: Line 9,848:




18




23




15
20




15
20






GROWTH OF THE INNER EAR OF ALBINO RAT






87




14


known, the inner and outer pillar cells when mature show a more
or less S-shaped curvature, though they are straighter in the
earlier stages. Thus the length as measured in the adult cochlea
is somewhat smaller than the natural lengths.


15




15
DEGREES
18




12


15


14




12




Line 8,792: Line 9,893:




25






50




30


5O 1OO 20O 300 40O 500






Chart 26 The angle subtended by the extension of the lamina relicularis
with the extended plane of the membrana basilaris, in degrees, table 58, fieure 1
4-4', 9
In table 61 (charts 27 to 32) is given the values for the lengths
of the inner and outer pillar cells according to age. At first we
shall consider the average values for the length of the inner
and outer pillar cells taken together. This length diminishes
at three days. From three to twelve days it increases rapidly,






88






ANATOMICAL AND PHYSIOLOGICAL STUDIES ON






and from twelve to twenty days more slowly. After twenty
days it decreases a little. The ratios at the bottom of the last
column show these relations. The familiar fact, that the length
increases from the base to the apex is clearly shown in chart 28.


9




12
TABLE 61




15


Lengths of the inner and outer pillar cells (without head) measured from the footplate
on the membrana basilaris to the point directly below the junction
(charts 27 to 32)


12




AOE


rabbit at seven days values homologous with those obtained in
the albino rat at fifteen days of age, only in the rat the breadth
is absolutely greater. In the cat the values at seven days of
age are about the same, or a bit smaller, than those in the albino
rat. Here again the rabbit is a trifle more precocious than the
rat, and the cat much more so.


Table 22 (chart 9) shows the values for the radial distance
BODY
between the outer corner of the inner pillar (not pillar cell)
WEIGHT




INNER PILLAR


GROWTH OF THE INNER EAR OF ALBINO RAT


OUTER PILLAR




53
Combined
Average




Turns of the cochlea M


TABLE 22


Radial distance between the outer corner of the inner pillar and the inner corner of  
Turns of the cochlea M
the outer pillar at base on age (chart 9)




I


AGE


II


BODY WEIGHT


 
ill
TURNS OF THE COCHLEA M




IV




Average




Line 8,868: Line 9,982:




II  
II ill
 
 
III




Line 8,883: Line 9,994:




grams
gms




Line 8,896: Line 10,007:




1




5




Line 8,910: Line 10,019:




1




5




28




29


3


29


8


29




29




24




27




27




26




26




28




6
3




11
8




25
26




28
23




29
26




34
23




29
25




9
19




10
20




27
20




30
21




35
20




30
23




31
6




12
11




13
35




37
36




41
36




51
37




53
36




46
21




15
26




13
27




35
26




46
25




56
31




56
9




48
10




20
35




29
39




43
41




53
40




66
39




68
26




58
26




25
29




36
29




42
28




58
34




67
12




68
13




59
33




50
38




59
44




41
44




54
40




68
46




74
59




59
72




100
72




112
62




44
51




59
15




71
13




78
34




63
38




150
48




183
51




Line 9,115: Line 10,235:




59
44




68
59




76
74




62
78




257
64




137
54




46
20




56
29




66
43




75
47




61
56




366
60




181
52




45
56




57
65




68
79




74
83




61
71




546
62




255
25




47
36




60
43




71
47




74
56




63
60




52


Ratios 6546 days
12546 "
20546 "


53




2.2
64
1.4
1.1




80


ou


14,
84


60
40
20


r\
70




61




50




59




42




44




55




61




51




52




64




79




84




70




*61




100




112




42




44




53




58




49




52




62




79




84




69




59




150




183




41




43




54




59




49




51




64




76




85




69




59




257




137




40




44




53




60




49




53




64




75




85




69




59




366




181




39




45




53




59




48




50




64




78




83




69




59




546




255




41




44




53




58




49




49




64




78




83




69




59




Ratios 1- 12 days




Line 9,378: Line 10,572:




1 1.4




Line 9,388: Line 10,583:




1 :2.4




1 : 1.8




1- 20 "




Line 9,398: Line 10,596:




1.8




Line 9,408: Line 10,607:




2.7




:2.2




1-546 "




Line 9,418: Line 10,620:




1.7




Line 9,428: Line 10,631:




2.7




:2.1




20-546 "




Line 9,438: Line 10,644:




0.9




Line 9,446: Line 10,653:




<




1.0




: 1.0




t=


When we calculate the average values of the inner and outer
pillar cells from Retzius table ('84), we get the following (table
62).


TABLE 62


Combined lengths of the inner and outer pillars from the foot plate to a point
directly below the junction in n (Retzius)






RABBIT (adult)




CAT (adult)




MM
MAN (adult)




Basal
turn




Middle
turn


.


Apical
turn


=


Average
turn




Basal
turn




Middle
turn




Apical
turn




Average




Basal
turn




Middle
turn




Apical
turn




Average




66




85


1


78




76




55




75




73




67




55




84




87




75




Line 9,521: Line 10,767:




'''Chart 27''' The length of inner and outer pillar cells combined, without
head, measured from the foot plate on the membrana basilaris to the point
directly below the junction, table 61, figure 2, /-/, 2-2.






'''Chart 28''' The length of inner and outer pillar cells combined, without
head, measured from the foot plate on the membrana basilaris to the point
directly below the junction, according to the turns of the cochlea, table 61.








'''Chart 29''' The length of inner pillar cell without head, table 61, figure 2, 1-1.




As table 62 shows, the values in these mammals are larger
than those in the albino rat a result which fits with our previous
observations.


When we consider the length of the inner pillar cells alone,
we see that the values (chart 29) here also increases from three
days to twenty days, but not so largely as in the combined values
of the inner and outer pillar cells. After twenty days the values
for the inner pillar cells decrease slightly. This relation is shown
by the ratios at the bottom of the corresponding column. That
the increase progresses from the base to the apex, being most
marked in turn III, is illustrated in chart 30. The condensed
table 63 shows those relations also. The one-day-old rat is an
exception.


We turn now to the growth in the length of the outer pillar
cells. As we see in table 61 (chart 31), the length of the outer
pillar cell does not increase so much from one to nine days as the
inner pillar cell did. At twelve days, however, the increase in
length is very marked, that is, 2.2 times as much as at nine days.


/
After the outer pillar cell reaches its maximum at twenty
days, it decreases only slightly with advancing age. The ratios
at the bottom of the corresponding column show this relation
clearly. The length increases from base to apex, though this
relation is not well established until twelve days, as shown in
table 61 and chart 32. The ratios of the outer pillar cells according to the turns of the cochlea are shown in table 64.


The inner and outer pillar cells show marked differences in
their growth. While at the earlier ages the length of the inner
is greater than that of the outer, yet after twelve days this
relation is reversed. Moreover, from nine to twelve days the
growth is gradual in the inner pillar cells, but rapid in the outer.
The condensed table 65 shows the values for the length of the
inner and outer pillar cells separately. In the last column are
given the ratios between them.


In the accompanying table 66 I have compared the values
obtained in the rat with those given by other authors.


As table 66 shows, the absolute values differ in various animals.
However, the ratios between the values for the inner and outer








'''Chart 30''' The length of the inner pillar cell without head, according to
the turns of the cochlea, table 61.




'''Chart 31''' The length of outer pillar cells without head, table 61, figure 2,




Line 9,548: Line 10,839:




'''Chart 32''' The length of outer pillar cells without head, according to the
turns of the cochlea, table 61.




TABLE 63 Condensed
Ratios of the length of the inner pillar cells according to the turns of the cochlea






AVERAGE AGE




AVERAGE BOOT
WEIGHT




RATIOS BETWEEN TURNS




I-II




I-II I




I-IV




days
1




grams
5




1 1.0




1 1.0




1 1.0




8




11




1.1




1.2




1.1




18




21




1.1




1.3




1.4




213




138


i


1.1




1.3




1.4






TABLE 64 Condensed
Ratios of the length of the outer pillar cells according to the turns of the cochlea






AVERAGE AGE




AVERAGE BODY
WEIGHT




RATIOS




BETWEEN TURNS




Line 9,624: Line 10,954:




I-II




I-II I




I- IV




days
1




grams
5




1 : 1.1




1 1.1




1 1.0




8




11




:1.2




1.3




1.3




18




21




: 1.2




1.5




1.6




213




138




: 1.3


/


1.5




1.6






TABLE 65 Condensed


Comparison of the average length of the inner and outer pillar-cellswithout


head.




Line 9,681: Line 11,038:




AVERAGE LENGTH OF PILLAR CELLS








AVERAGE AGE




AVERAGE BODY




WITHOUT HEAD




RATIOS OF INNER








\V V T ( ' H T








TO OUTER




Line 9,705: Line 11,069:




Inner




Outer








days




grams




Line 9,721: Line 11,089:




1




5




29




26




1 :1.0




8




11




35




34




:1.0




18




21




48




68




:1.4




213




13S




50




69.




: 1.4






pillar cells are smallest in man and in the rat and alike in the
other two forms, Retzius ('84). Hensen ('63) states that in the
base of the human cochlea both pillar cells are equally long.
Later, Pritchard ('78) supported this observation. In the
literature, however, no one except these two authors report the
inner and outer pillar cells in the base of the adult cochlea as
equal in length, but the inner is always stated to be shorter than
the outer. We may therefore say that most authors agree that
the inner pillar cells are at earlier stages longer than the outer,
then they become equal, and finally the outer surpass the inner.








TABLE 66


Lengths of inner and outer pillars in several mammals according to different authors.


Measurements in n






INNER PILLAR




OUTER PILLAR




Authors




Animals




Basal
turn




Middle




Apical








Av.




B.




M.




A.






i


Av.




Ratio




Corti




Mammals




30




30




34




31




4549




54
58




69




57




1:1.8




Hensen




Man




48




Line 9,833: Line 11,262:




86
(Hamul
us)




48




Line 9,842: Line 11,275:




98
(Hamulus)








Ret
zius


Wada




Rabbit




56




60




60




59




75




110




1
95
 
 
 
 




93




:l.




Cat




41




54




57




51




68
62




95




89




84




:1.6




Man




48




68




70




62




100




103




88




:l.t




Albino
rat
after 20
days




I
41




II
45




III


54




IV


59




50




I
52




II
64




III


78




IV


84




70




-.1.4






16. Inner and outer hair cells. For a long time the inner
and the outer hair cells have been regarded as the most important
elements in the papilla spiralis. As these sense cells have a
delicate histological structure which is readily altered, the
systematic study of their growth, especially after the appearance
of hearing, is a difficult matter. Though there are some observations
on the length of these cells, detailed studies on their growth
have not been made heretofore. I have therefore endeavored
to follow the changes of their size during the postnatal period.
It is first necessary to determine the form of these cells. They
are generally described as cylindrical, but this description is
inexact. Moreover, the inner and outer hair cells are somewhat
different in shape. The former has on the surface a large oval
terminal disk, which is wide hi the spiral and narrow in the
radial direction. This narrows downwards to a thinner neck
which expands into the broader body and terminates in a more
or less round but somewhat pointed irregular end.






94








'''Chart 33''' The weighted volume of inner and outer hair cells combined,
and of their nuclei in cubic micra, tables 67 and 69.


- Weighted volume of inner and outer hair cells combined.
Weighted volume of nuclei of inner and outer hair cells combined.


The outer hair cells have a much more cylindrical form,
their upper terminal disk is not so wide and not round, but
hexagonal. They become a bit thin in the neck, then wide in
the body. Their lower end is rounded. In order, however, to
determine the cell volume, the cell form has been taken as that
of a cylinder. For computation, the average of the diameters
measured in three places, the end disk, neck, and cell body, was
taken as the diameter and the length of the cell as the length of
the cylinder. From these data the volume of the cylinder was
computed.








In table 67 are given the values for the volume of the cell
bodies in the (1) inner and (3) outer hair cells separately and
the weighted volume of both cells (in the radial section of the
rat cochlea we see one row of inner and three rows of outer
hair cells), according to age.


TABLE 67


Average volumes of the inner and outer hair cells in cubic micro
(charts 33 to 37)






AGE








INNER HAIR CELL




OUTER HAIR CELL








BODY
WGHt




Tu


I




rns of
II




the o
III




achlea
IV




fit
Average




T
I




urns o
II




f the (
III




iwlilr;


IV




l M 3
Average




WEIOHTD
AVERAGE
VOLUME




days
1




gms
5




1255




982




832




631




925




641




626




505




359




533




631




3
6
' 9
12
15
20




8
11
10
13
13
29




1457
1374
1451
1553
1598
1627




1367
1451
1734
1812
1618
1764




1206
1549
1994
1910
1902
1972




913
1221
2013
2157
2128
2189




1236
1399
1798
1858
1812
1888




767
1047
914
818
815
894




928
967
1308
1210
1178
1215




867
1053
1459
1602
1595
1606




571
800
14^8
1499
1559
1960




783
967
1277
1282
1287
1419




896
1075
1407
1426
1418
1536
1293




Av. 11




14




1510




1624




1756




1770




1665




876




1134




1364




1303




1169




25
50
100
150
257
366
546




36
59
112
183
137
181
255




1540
1497
1353
1362
1345
1290
1266




1655
1611
1550
1497
1524
1561
1486




1909
1821
1744
1683
1738
1817
1772




1995
1924
2018
1917
1976
2297
2257




1775
1713
1666
1615
1646
1741
1695




834
805
837
832
873
893
831




1243
1204
1306
1150
1230
1239
1336




1539
1580
1510
1803
1555
1651
1650




1702
1906
1737
1917
1927
1844
1839




1330
1374
1348
1426
1396
1407
1414




1441
1459
1428
1473
1459
1491
1484




Av. 213




138




1379




1555




1783




2055




1693




844




1244




1613




1839




1385




1462




Ratios 1- 12 days
1- 20 "
1-546 "
20-546 "
1- 11 "
11-213 "




1 :2.0
:2.0


0^9








1 :2.4
:2.7
:2.7


:2!2




1 :2.3
:2.4
:2.4
:0.9
:2.0






At first we shall consider the weighted volume for the cell
bodies of the inner and outer hair cells combined (chart 33).
As table 67 shows, the volume increases continuously to the full
size at twenty days. From one to twelve days the increase is
rapid, and after that the volumes are about the same, though
somewhat fluctuating. The ratios show this relation clearly.




Condensing all age groups into three (averages in table -67),
then the relation changes somewhat. From one to eleven days
the volume increases more than 100 per cent, while from eleven
to 213 days it increases only 13 per cent.






'''Chart 34''' The volume of inner hair cells and of their nuclei, tables 67 and 69.


Volume of inner hair cells.
Volume of nuclei of inner hair cells.


The data for the growth of the nuclei of the inner and outer
hair cells are presented in tables 68 and 69. The weighted
values for the diameters of the nuclei (table 68) are large at
the earlier stages, but from twelve days decrease gradually till old age. In the three condensed age groups (averages) we see
the decrease of the values from birth till old age. In table 69
are given the values for the volumes of the nuclei, calculated
as spheres (chart 33).






'''Chart 35''' The volume of inner hair cells, according to the turns of the
cochlea, table 67.




The weighted values for the volumes of the inner and outer
hair cells in each turn are given in [A 3 table 70. At the bottom
of each column is given the ratio from 1 to 12, 1 to 20, 1 to 546,
and 20 to 546 days of age. While the volume at birth is largest
in turn I and smallest in turn IV, that in turn III is largest at






'''Chart 36''' The volume of outer hair cells and of their nuclei, in cubic micra,
tables 67 and 69.


Volume of outer hair cells.


._. Volume of nuclei of outer hair cells.


six days. After nine days the volume increases always from base
to apex.


Comparing the weighted vo'ume in each turn according to
age, we find that the rate of increase in volume is smallest in
turn I (1.3 to 1.2) and largest in turn IV (3.9 to 4.6) (table 70).


In table 72 are given the weighted values for the diameters
of the nuclei of the inner and outer hair cells in each turn. They increase and then decrease during the first twelve days. The rate of
decrease is largest in turn I, and smallest in turn IV, as the ratios
at the bottom of each column show. That the diameters at






'''Chart 37''' The volume of outer hair cells, according to the turns of the
cochlea, table 67.


the later ages have about the same value in each turn, or are a
little larger in the upper than in the lower turn, is to be seen
in table 73.






TABLE 68
Mean diameters of the nuclei of the inner and outer hair cells in M




Line 10,170: Line 11,999:




DIAMETERS NUCLEI OF THE




DIAMETERS NUCLEI OF THE






INNER HAIR CELLS




OUTER HAIR CELLS






WEIGHT


G
AGE




E
BODY


wght


DA>


Turns of the cochlea ju


/C


Turns of the cochlea M




ED
AVERAGE




Line 10,200: Line 12,037:




I




II




ill




IV




Average




I




II




ill




IV




Average








days




gms.






1




5




8.6




8.3




7.8




7.8




8.1




7.7




8.1




7.4




1
7.6




13
7.7




7.8


o


3




25
8




8.6


50


8.5




50 1OO 20O 3OO 40O 5OO
8.2




7.8


Chart 9. The radial distance between the outer corner of the inner pillar
(not pillar cell) and the inner corner of the outer pillar (not pillar cell) at base,
table 22, figure 2, distance 6.


8.3




54
8.3




8.4


ANATOMICAL AND PHYSIOLOGICAL STUDIES ON


8.J




and the inner corner of the pillar (not pillar cell) at the base,
7.5
on age. At the bottom of the last column are given the ratios
from 6 to 546, 12 to 546, and 20 to 546 days. As just stated,
the inner, and especially the outer rods, do not appear in the
respective pillar cells at the earliest stage, the latter becoming
evident a bit later than the former. After six days of age the
distance between them can be determined.  


As table 22 shows, this distance increases at first rapidly,
then more slowly with age. This agrees with the growth of the
membrana basilaris, as already noted. While the value at 546
days is over twice as large as at six days, it is but little larger
than at twenty days, as the ratios show. Moreover, the distance
increases from the base toward the apex rapidly up to turn


TABLE 23 Condensed
8.1


Ratios of the radial distance between the outer corner of the inner pillar and the
inner corner of the outer pillar, at base according to turns
of the cochlea on age


8.2




6




11




BATIO8 BETWEEN TURNS
8.5




8.6




8.3




I-II
8.0




i-m
8.3




I-IV
8.0




days
8.0




grams
8.1




7.9




8.0




8.1




8
c




11
10




1 : 1.1
8.7




1 : 1.2
8.5




1 : 1.2  
8.2  




14
8.7




13
8.5




: 1.2
76




: 1.5
7.9




: 1.5
8.4




189
8.2




124
8.0




:1.3
8.1  




:1.5
12




:1.7
13




7.6


III and less rapidly to turn IV. This relation is more concisely
presented in table 23. Retzius ('84) gives the value of this
distance in the rabbit and the cat as follows (table 24).


The table 24 shows that there is no measurable distance
7.7
between the outer corner of the inner pillar and the inner corner
of the outer pillar at the very early stage in the rabbit, and this
result is like that for the albino rat. Later the distance is larger
in the rabbit than in the rat. The rate of increase of the values
from the base to the apex is, however, similar in both forms.
In the cat, on the other hand, there is already at birth a large
distance between the pillars. The cochlea of the cat is therefore at this period more advanced in this character than that of
the rabbit or rat, but in the cat also the distance tends to increase from the base toward the apex.  




7.5


GROWTH OF THE INNER EAR OF ALBINO RAT


7.9




55
7.7




5.8


In table 25 (chart 10) are given the values for the radial
distance between the habenula perforata and the outer corner
of the inner pillar cell (resp. the inner corner of the outer pillar
cell) at the base according to age. This table is derived from
tables 18, 19, and 22. The values from one to nine days of age
are from table 18. Those after twelve days consist of the sum
of the values in table 19 plus the one-half of those given in table
22 (fig. 2 value for bracket 3 plus one-half the value for bracket
6).


TABLE 24
6.5


Radial distance between the outer corner of the inner pillar and inner corner of the


outer pillar in n (Retzius)
6.8




7.4


RABBIT


6.6


CAT


6.9


Age


15


Basal
turn


13


Middle
turn


7.5


Apical
turn


7.5


Average
turn


7.7


Basal
turn


7.9


Middle
turn


7.6


Apical
turn


6 1


Average
turn


6.6


days


6.8




7.0




6.6




6.9




20




29




7.0




7.3




7.6


New-born


7.8




7.4




6.0




6.4




6.9




7.3




6.6


64


6.8




Av. 11




14




8.0




8.0




2
7.9




8.0




8.0




7.0




7.3




7.5




7.6




7.3




7.5




25




36




7.3




7 2




3
7.2




7.1




7.2




6.0




6.3




6.3




6.5




45
6.3




6.5




50




59




7.0




75


7


7.3


57


7.3


75


7.3


75


6.0


69


6.2


50


6.3


75


6.7




6.3




6.6




100


10


112


52


6.7


72


7.0


74


7.1


66


7 1




7.0




5.8




6.0




6.0




6.0




5.9


11


6.2




150




183




6.6




6.8




7.0




7.3


75


6.9


95


6.0




6.0




6.2




6.1


14


6.0


63


6.2


100


257


99


137


87


6.6




6.9




7.0




7.7




7.0




5.9 16.0




6.2


30


6.4




6.1




6.3




366




181




7.6




7.4


66


7.3


93


7.2


90


7.4


83


5.9




The values increase gradually after birth till nine days, when
6.0
they reach a maximum, and then decrease, but increase again
very gradually till old age. If this method of measurement is
accepted, then the inner corner of the inner pillar cell lengthens
inward at the base in the earlier stages. At the time when the
inner pillar reaches the habenula perforata, the outer corner
of the inner pillar has not yet moved inward, and thus the breadth
of the base is largest. After the inward wandering of the inner
pillar cell, the base diminishes a little in its breadth; then it
increases slightly with advancing age.  


When considered according to the turn of the cochlea, this
measurement generally increases from the base to the apex,
but more rapidly from turn I to turn III, and only slightly from


6.1




56
6.0




6.0


ANATOMICAL AND PHYSIOLOGICAL STUDIES ON


6.4




TABLE 25
546


Radial distance between the habenula perforata and the outer corner of the inner


pillar cell (resp. the inner corner of the outer pillar cell) at base on
255


age. Derived from tables 18, 19 and 22 (chart 10)


6.5




AGE
6.5




BODY WEIGHT
6.5




TURNS OF THE COCHLEA M
7.1




I
6.6




II
5.8




III
6.0




IV
6.1




Average
6.4




days
6.1




grams
62




Av. 213! 138




6.9




7.0




71




7.3




1  
7.1  




5  
5.9




40
6.1




41
6.2




39
6.3




39
6.1




40
6.3




3
Ratios 1- 12 days




8
1:1. 0,|




46
1 :0.9|| 1 :0.9




49
1- 20 "




49
:0.9




49
:0.9 :0.9




48
1-546 "




6
:0.8




11




38
:O.S 0.8




45
20-546 "




58
:0.9 |




53
:0.9 :0.9




49


TABLE 69
Average volumes of the nuclei of the inner and outer hair cells (charts 33, 34 and 36)


9




10
AGE




44
BODY WEIGHT




46
VOLUME OF NUCLEUS HAIR CELLS


Inner Outer


56


WEIGHTED
VOLUMES
INNER AND OUTER
HAIR CELLS


53


days


50


gms.


12


M'


13


M


36


M 3


45


1


50


5


50


278


45


239


15


248


13


3


36


8


41


299


47


278


47


289


43


6


20


11


29


299


36


268


42


278


48


9


49


10


44


322


25 .


268


36


278


35


12


44


13


48


239


49


151


44


172


50


15


59


13


35


230


41


151


48


172


50


20


44


29


100


212


112


151


36


165


44


25


50


36


52


195


46


131


150


144


183


50


36


59


45


204


49


131


53


151


46


100


257


112


137


180


38


108


43


125


48


150


51


183


45


172


366


113


181


125


39


257


45


137


49


180


52


119


46


131


546


366


255


181


39


212


44


113


52


137


52


546


47


255




Ratios 1 546 days
151
9546 "
12546 "
20546 "




119


1.2
0.9
1.0
1.1


125




60


JLL
Ratios 1- 12 days
1- 20 "
1-546 "
20-546 "


40
20


c\


1 :0.9
:0.8
:0.5
:0.7






:0.6
:0.6
:0.5
:0.8






:0.7
:0.7
:0.5
:0.8






100






GROWTH OF THE INNER EAR OF ALBINO RAT






101






The growth of the inner hair cell. The volume of the inner
hair cell table 67 (chart 34) increases with age up to twenty


TABLE 70


Weighted volumes of the inner and outer hair cells according to the turns of the


cochlea






AGE




BODY WEIGHT




TURNS OF THE COCHLEA M*




I




II




ill




IV




days




gms.




Line 11,147: Line 13,067:




1




5




795




715




587




427




3




8




940




1038




952




657




6




11




1129




1088




1177




905




9




10




1048




1415




1593




1574




12




13




1002




1361




1679




1664




15




13




1011




1288




1672




1701




20




29




1052




1352




1698




2017




25




36




1011




1346




1632




1775




50




59




978




1306




1640




1911




100




112




966




1367




'1569




1807




150




183




965




1237




1773




1917




257




137




991




1304




1601




1939




366




181




992




1320




1693




1957




^
546




r*
255




r^
940




1374




1681




1944




_ !


Ratios 1- 12 days


1


1 : 1.3 1




1.9




1 :2.9




1 :3 9




1- 20 "




:1.3




1.9




:2.9




:4.7




1-546 "




: 1.2




1.9




:2.9




:4.6




20-546 "




:0.9


e=


1.0




:1.0




:1.0






TABLE 71 Condensed


Ratios of the weighted volumes of the inner -and outer hair cells according to the turns


of the cochlea




-_




Line 11,373: Line 13,393:




BATI08 BETWEEN TURNS




AGE




BODY WEIGHT




I-II




i-ni




I-IV




days




0ms.




Line 11,395: Line 13,423:




1




5




1 :0.9




1 :0.7




1 :0.5




8




11




:1.2




:1.3




:1.2




18




21




:1.3




: 1.6




: 1.8




213




138




:1.4




:1.7




:1.9






days; to nine days rapidly, then slowly. After twenty days it
decreases slowly, as do the weighted volumes of the inner and
outer hair cells, and with fluctuations, is nearly the same after






102






ANATOMICAL AND PHYSIOLOGICAL STUDIES ON






100 days. The three condensed age groups show that from
1 to 11 days it has increased 80 per cent, while from 11 to 213
days it has gained less than 2 per cent.


TABLE 72


Weighted diameters of the nuclei of the inner and outer hair cells according to the


turns of the cochlea






AGE




BODY WEIGHT




TURNS OF THE COCHLEA M




I




II




ill




IV




days




gms.




Line 11,477: Line 13,545:




1




5




7.9




8.2




7.5




7.7




3




8




8.4




8.4




8.1




7.6




6




11




8.1




8.2




8.2




7.9




9




10




7.9




8.1




8.4




8.3




12




13




6.3




6.8




7.0




7.5




15




13




6.5




6.8




7.0




7.2




20




29




6.3




6.6




7.1




7.4




25




36




6.3




6.5




6.5




6.7




50




59




6.3




6.5




6.6




6.9




100




112




6.0




6.3




6.3




6.3




150




183




6.2




6.2




6.4




6.4




257




137




6.1




6.2




6.4




6.7




366




181




6.3




6.4




6.4




6.3




546




255




6.0




6.1




6.2




6.6






Ratios 1- 12 days




1 :0.8




1 :0.8




1 :0.9 1




1.0




1- 20 "




:0.8




:0.8




:0.9




1.0




1-546 "




:0.8




:0.7




:0.8




0.9




20-546 "




: 1.0




:0.9




:0.9




0.9






TABLE 73. Condensed


Ratios of the weighted diameters of the nuclei of the inner and outer hair cells
according to the turns of the cochlea




Line 11,695: Line 13,870:




RATIOS BETWEEN TURNS




AVERAGE AGE




AVERAGE BODY




Line 11,705: Line 13,883:




WEIGHT




Line 11,717: Line 13,896:




I-II




i-m




I-IV




days




gms.




Line 11,733: Line 13,917:




1




5




1 :1.0




1 0.9




1 1.0




8




11




:1.0




1.0




1.0




18




21




:1.0




1.1




1.1




213




138




:1.0




1.0




1.1






From nine days on the volume of the inner hair cell increases
in passing from the base to the apex. During the earlier stages






GROWTH OF THE INNER EAR OF ALBINO RAT






103






there are some fluctuations (table 67, chart 35). In the condensed table 74 the general relations are shown. The growth
of the nuclei of the inner hair cells in diameter is given in table 68.
As we see, the diameters increase from birth to nine days,
then decrease slowly but steadily. In the three average age
groups, however, the values decrease continuously with age.
In table 69 are given the values for the volumes of the nuclei
of the inner hair cell (chart 34).


TABLE 74 Condensed
Ratios of the volume of the inner hair cells according to the turns of the cochlea


RATIOS BETWEEN TURNS




AVERAGE AGE




AVERAGE BODY




Line 11,795: Line 14,015:




WEIGHT








I-II




i-in




I-IV




days




grams




Line 11,815: Line 14,041:




1




5




1 0.8




1 0.7




1 0.5




11




14




1.1




1.2




1.2




213




138




1.1




1.3




1.5






TABLE 75 Condensed


Ratios of the diameters of the nuclei of the inner hair cells according to the turns of the cochlea




RATIOS BETWEEN TDRN8




AVERAGE AGE


G


AVERAGE BODY


^




c




A


WEIGHT


/s




Line 11,876: Line 14,118:




I-II




I-II I




I-IV




days




grams




Line 11,892: Line 14,139:




1




5




1 1.0




1 :0.9




1 0.9




11




14




1.0




:1.0




1.0




213




138




1.0




:1.0




1.1






25
The ratios of the diameters of the nuclei of the inner hair
cells decrease at the earlier ages in each turn from the base to
the apex. After nine days they are nearly the same in all the
turns (tables 68 and 75), though their absolute values decrease
in all the turns after nine days.


The growth of the outer hair cells. In general, the changes in
the volume of the outer hair cells are like those in the inner
hair cells. Therefore, the volume increases strikingly up to nine
days of age, then gradually to twenty days. The main difference is that the volume in the outer hair cells does not diminish
so much after twenty-five days, but holds nearly the same value
(table 67, chart 36). In condensed age groups, therefore, we see
a large increase in the size of the cells with age.


To determine the growth of the outer hair cells in each turn
of the cochlea, table 67 is used (chart 37). From twenty days on
the values increase from the basal to the apical turn. Before
twenty days the relations are irregular or reversed. In table
76 this relation is clearly brought out.


50
Comparing the changes of the volume of the outer hair cells
in three age groups (table 67), we find that the average volume
increases throughout each turn with age, except in turn I, where






50 1OO 2OO 3OO 4OO 5OO
TABLE 76 Condensed
Ratios of the volumes of the outer hair cells according to the turns of the cochlea




RATIOS BETWEEN TURNS


Chart 10 The radial distance between the habenula perforata and the
outer corner of the inner pillar cell (resp. the inner corner of the outer pillar
cell) at base, table 25, figure 2, distance 8.


AVERAGE AGE




GROWTH OF THE INNER EAR OF ALBINO RAT
AVERAGE BODY






57






turn III to IV. Table 26 shows this relation. While at birth
WEIGHT
the ratio is in all turns the same, 1 :1.0, at other ages it is always
higher. Retzius ( '84) gives the results obtained from the rabbit
and the cat as follows (table 27).






TABLE 26 Condensed
I-II




i-in


Ratios of the radial basal distance between the habenula perfcrata and the outer


corner of the inner pillar cell (resp. the inner corner of the outer pillar
I-IV


cell) at base on age according to the turns of the cochlea


days




grams








RATIOS BETWEEN TURNS




AGE




BODY WEIGHT
1




5




1 1.0




1 0.8




I-I1
1 0.6




I-HI
11




I-IV
14




days
1.3




gram*
1.6




1.5




213




138




1  
1.5




5
1.9




1 1.0
2.2




1 :1.0


that at eleven days is largest. In the inner hair cells, however,
values at eleven days are largest in both turn I and II.


1 :1.0
For the nuclei of the outer hair cells, the diameters are given
in table 68). Here the d ! ameters tend to increase from one to
nine days. At twelve days they decrease strikingly, and after
that very slowly. In table 69 are given the values for the volumes
of the nuclei of the outer hair cells.  


In table 68 are given also the measurements for the nuclei
of the outer hair cells according to the turn of the cochlea.
At nine days and after, the diameters become larger in passing
from base to apex, while in the earlier stages this relation is
irregular or reversed. The decrease of the measurements in,
each turn with age is clearly shown in the three age groups.


8




11
In table 77 are given the average ratios of turn I to the three
other turns.


The comparison of the growth of the inner and outer hair
cells. As already stated, the growth of the inner and outer hair
.cells in volume proceeds in about the same way till they reach
their full size at twenty days. After that we note a difference
between them. While the outer hair cells maintain a nearly
constant volume, the volume of the inner hair cells diminishes


1.2
TABLE 77 Condensed


Ratios of the diameters of the nuclei of the outer hair cells according to the turns of


:1.4
the cochlea




: 1.3




18




21


RATIOS BETWEEN TURNS


1.2


AVERAGE AGE


:1.3


AVERAGE BODY


: 1.3




213




138


WEIGHT


1.2




:1.S




:1.4






TABLE 27






Distance between the habenula perforata and the outer corner of the inner pillar


cell in n (Retzius)
I-II




I-II I


Age


I-IV


Basal
turn


days


Middle


turn
grams




Apical
turn




Average
turn




Basal
turn




Middle
1
turn




Apical
5
turn




Average
1 1.1
turn




days
1 1.0




1 1.0




11




14




1.0




1.1




1.1




213




138




New-born
1.0




30
1.1




45
1.1




39


TABLE 78 Condensed
Comparison of the volumes of ike inner and the outer hair cells


38




60




60




60
AVERAGE VOLUMES HAIR CELLS




60




2
AVERAGE AGE




30
AVERAGE BODY




36




30
RATIOS OF INNER




32




WEIGHT




Line 12,182: Line 14,466:




TO OUTER




Line 12,188: Line 14,473:




3
Inner




Outer








days




grams




M




A




44




60
1




5




925




533




7
1 0.6




37
11




46
14




45
1665




43
1169




45
0.7




69(?)
213




65
138




60
1693




10
1385




39
0.8




52


somewhat with age. When we consider the volume according
to the three age groups, it increases in both groups throughout
life (table 78). There are, however, large differences in the rate
of increase. The inner hair cell increases its volume at 11 days
by 80 per cent and between 11 and 213 days by less than 2 per cent.
For the outer hair cells the increase by 11 days is 120 per cent
and from 11 to 213 days, 19 per cent. At the same time the inner
are always larger than the outer hair cells, as the ratios in table
78 show.


48


The diameters of the nuclei in both the inner and outer hair
cells diminish in value after nine days of age. This decrease
is larger in the outer than in the inner cells. In table 79 are
given the values for the diameters of the nuclei in both inner and
outer hah* cells. In the last column are the ratios between them.


46
Thus, while the volumes of the outer hair cells, as compared
with the inner hair cells, become relatively larger with age (table
78), the diameters of their nuclei become relatively smaller
(table 79).


TABLE 79 Condensed
Comparison of the diameters of the nuclei of the inner and outer hair cells




Line 12,263: Line 14,572:




AVERAGE DIAMETERS OF THE






AVERAGE




NUCLEI OF THE HAIR CELLS


11


RATIOS OF THE AVERAGE
DIAMETERS OF THE NUCLEI OP




AVERAGE AGE




BODY




Line 12,284: Line 14,599:




60


WEIGHT


66


Inner


75


Outer


67


CELLS


14


days


40


grams


54


M


51


M


48




Line 12,314: Line 14,628:




1




5




8.1




7.7




1 1.0


30






11




14




8.0




7.3




0.9








213




60
138




60
7.1




6.1




0.9




At the earlier stage this distance in the rabbit is a little less
than in the rat. Soon after, however, it becomes about the same.
In the cat the values are generally larger than in the rat.


5. Radial basal breadth of the outer pittar cett (including
the outer pillar). The measurement of the radial basal breadth
of the outer pillar cell is difficult. At the earlier stage, in which the
inner and outer pillar cells are in contact with each other along




Comparison of the growth of the inner and outer hair cells
according to sex. A careful and elaborate comparison has been
made to determine whether there are differences in the growth
of the hair cells according to sex.


58
In table 80 are given the average values for the volumes of
the cell bodies and their respective nuclei. No significant differences according to sex were found.


Comparison of the growth of the inner and outer hair cells
according to side. The same treatment of the data was followed
as in the determination for the influence of sex. In table 81 are
given the average values for the volumes of the inner and outer
hair cells and their respective nuclei. Again no significant
differences according to side were found.


On the nucleus-plasma ratios of the inner and outer hair cells.
For the inner and outer hair cells here measured the weighted
volumes of the cell bodies and of their nuclei are entered in the
condensed table 82, and the ratios of the volume of the nucleus to that of the cytoplasm (=cell volume less nucleus volume)
are given in the last column. This ratio increases with age,
as table 82 shows. While the ratio is 1.5 in the youngest and
smallest group, it is 9.9 in the largest. This means that as a
group these cells are continually growing in volume. This result
may be analysed for the two groups of cells involved.


ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
TABLE 80


Average volumes of inner and outer hair cells and of their respective nuclei


in n 3 according to sex


Radial basal breadth of the outer pillar cell (including the outer pillar) from one


to nine days of age




INNER HAIR CELLS




OUTER HAIH CELLS




WEIGHTED AVERAGE


TURNS OF THE COCHLEA M


Att


AGE


BODY


BODY WEIGHT


NO. OF




BEX




Average volume


Average volume




I
VOLUME




II




III




IV
BATS




Average
Cell




days
Nucleus




grams
Cell




Nucleus




CELLS




NUCLEI




da j/5




grams




1




5




10




9




8




8




9




3




8
3




15
7




16
1




15
0*




12
1213




15
310




6
815




11
268




26
915




28
278




28




33
8




28
1




Line 12,492: Line 14,832:




10
1319




26
310




30
888




30
322




35
996




30
319




6


TABLE 29
Radial basal breadth of the outer pillar on age (chart 11)


11




AGE
2




BOOT WEIGHT
tf




TURNS OF THE COCHLEA M
1426




I
289




II
955




III
278




IV
1073




Average
281




days




grams
10




2




9




1372




310




979




1
268




5
1077




278




9




10




2




cT




1701




310




1351


3


258


S


1439




271








9




2




9




1895




345




6
1203




11
278




10
1376




14
295




16
12
 
 
17




Line 12,619: Line 14,974:




9
2




10
c? 1




15
1830




18
258




18
1344




21
157




18
1466




12 .
182




13




14
12




23
2




25
9




22
1886




21
221




15
1221




13
151




17
1387




21
168




23
100




20
146




20
1




20
cT




29
1687




13
180




13
1342




16
113




15
1428




14
129




25




36
103




14
1




13
9




14
1779




14
212




14
1319




50
108




59
1434




14
184




14
150




15
189




14
1




14
rf 1




100
1679




112
165




14
1382




15
119




16
1456




15
131




15




150
154




183
1




15
9




15
1639




15
212




16
1611




15
119




257
1618




137
142




15
365




16
205




17
1




17
tf




16
1739




366
258




181
1389




15
119




16
1477




17
154




18




16
170




546
1




255
9




16
1659




15
221




17
1486




17
113




16
1529




140


Ratios


1
Volume greater in male 3
2


40
A
20


n
2




6546 days 1
3
2546 "
0546 "




1.1
4
0.8
1.1




5




3




Volume greater in female 4




4




4




2




2




4




Equal




1




Line 12,896: Line 15,249:




1




Line 12,901: Line 15,255:




.






The nucleus-plasma ratio of the inner and outer hair cells
considered separately. This is shown for the inner hair cells
in table 83. The ratios are also progressive, but somewhat
larger for the earlier age groups and smaller for the oldest, than
in the previous instance.


The ratios for the outer hair cells are also progressive, and
the range is greater than for the inner hair cells as table 84 shows.
Here the ratio is 1.2 for the youngest group and 10.6 for the oldest. This indicates that at one day and eleven days the
relative volume is less in the outer than in the inner hair cells,
but at the later age the outer hairs cells grow more.






TABLE 81






Volumes of the inner and outer hair cells and of their respective nuclei according


to side in ft 3






AGE




BODY
WEIGHT




NO. OF


BATS




SIDE




INNER HAIR CELLS




OXJTER HAIR CELLS




WEIGHTED AVERAGE
VOLUME




Average volume




Average volume




Cell




Nucleus




Cell




Nucleus




CELLS




NUCLEI




1




5




2




R.




895




299




555




248




640




261




Line 12,972: Line 15,368:




L.




955




268




511




230




622




239




3




7




1




R.




1213




310




815




268




915




278




Line 13,012: Line 15,425:




L.




1395




299




920




299




1039




299




6




11




2




R.




1381




322




1010




278




1103




289




Line 13,052: Line 15,482:




L.




1416




289




923




258




1046




268




9




9




2




R.




1782




310




1177




268




1328




278




Line 13,092: Line 15,539:




L.




1815




333




1378




268




1487




284




12




12




1




R.




1887




212




1310




151




1454




166




Line 13,132: Line 15,596:




L.




1885




221




1132




151




1320




168




15




13




t
1




R.




\,
1895




230




1522




144




1615




165




Line 13,172: Line 15,651:




1




-=a
L.




<
1848




239




-<
1419




151




1526




172




20




29




2




R.




1914




212


,


1365




144




1502




161




Line 13,219: Line 15,710:




L.




1862




221




1472




165




1570




179




25




36




2




R.




1758




204




1307




131




1420




149




Line 13,259: Line 15,767:




L.




1792




195




1351




131




1461




147




50




59




2




R.




1741




204




1443




125




1518




145




Line 13,299: Line 15,824:




L.




1687




204




1305




137




1401




154




100




102




2




R.




1675




187


G


1355




113


D


1440


A'


131


^






123




2




L.




1658




172




1339




113




1419




128




150




189




1




R.




1565




172




1420




113




1456




128




Line 13,383: Line 15,940:




L.




1679




165




1382




119




1456




131


i


257




25
137




2


50


R.




5O 1OO 2OO 300 4OO 500
1685




187


Chart 11 The radial basal breadth of the outer pillar (not pillar cell)
table 29, figure 2, distance 7.


1377




GROWTH OF THE INNER EAR OF ALBINO RAT
125




1454


59


140




their whole length, we can easily measure this distance. After
twelve days, however, the breadth consists of the sum of the
radial breadth of the outer pillar and the half of the radial
distance between the outer corner of the inner pillar and the
inner corner of the outer pillar, as previously explained.


In table 28 are given the values for the radial basal breadth
of the outer pillar cell (including the outer pillar) from birth
to nine days of age. These values show a rapid increase. According to the turn of the cochlea, the breadth at birth diminishes
from the base to the apex. At three days it increases already in
turn II, but at the later ages it increases gradually from the
base to the apex.


TABLE 30 Condensed


Ratios of the radial basal breadth of the outer pillars on age according to the


turns of the cochlea




L.




1607




180


RATIOS BETWEEN TURNS


1416


AGE


119


BODY WEIGHT


1464




134




367




175


I-II


2


I-III


R.


I-IV


1634


days


195


grams


1436




113




1486




134


8


365


11


188


1 -1.2


2


1 1.3


L.


1 1.5


1848


14


230


13


1374


:1.4


113


1.5


1493


1.3


142


189


546


124


255


: 1.0


2


1.1


R.


1.1


1831




In table 29 (chart 11) are given the values for the radial
157
basal breadth of the outer pillar (not pillar cell). As in the case
of the inner pillar, here also the outer pillar first appears distinctly
at six days of age. After the continuous increase of the values till
twelve to fifteen days, they decrease suddenly at twenty days,
and then increase again very slowly. This relation is clearly
shown by the ratios at the bottom of the last column. That
the values tend to increase from the base toward the apex is
also shown, though there are some exceptions. Table 30 gives
the condensed results.


From Retzius' work ('84) we have calculated the values for
the radial basal breadth of the outer pillar in the rabbit and cat
as follows (table 31).


There are large differences between my results and those
1474
of Retzius during the earlier stage, especially in the rabbit.




119


60


1563




ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
128






At birth, the inner pillar has not yet distinctly developed at
the base of the pillar cell in the rabbit and the rat, as above
stated. We know that the development of the elements of
the cochlea proceeds generally from the axis to the periphery, as


TABLE 31


Radial basal breadth of outer pillar measured in n (from Retzius)






RABBIT
L.




CAT
1559




Age
151




Basal
1353
turn




Middle
119
turn




Apical
1405
turn




Average
127




Basal
Volume greater on right side 7
turn




Middle
8
turn




Apical
9
turn




Average
3




days
7




,
6




Volumfe greater on left side 7




5




5




5




6




8




Equal




New-born
1




15?




12?


6


7?


1


11?




25




15


GROWTH OF THE INNER EAR OF ALBINO RAT






109






This seems to be important and to illustrate the fact that in
the papilla spiralis the growth of the elements lying nearer the
axis occurs earlier than that of the elements nearer the periphery.


2
TABLE 82 Condensed
Nucleus-plasma ratios of the inner and outer hair cells M*




50


AVERAGE
AGE


45


AVERAGE
BODY
WEIGHT


44


AVERAGE VOLUME OF
INNER AND OUTER HAIR CELLS


46


VOLUME OK
CYTOPLASM




NUCLEUSFLA8MA RATIOS




Cell




Nucleus




days


1


11


213




3
grams
5
14
138




631
1293
1462




248
226
134




383
1067
1328




1 : 1.5
:4.7:9.9




TABLE 83 Condensed
Nucleus-plasma ratios of the inner hair cells /**




AVERAGE
AGE




20
AVERAGE
BODY
WEIGHT




AVERAGE VOLUME OF 1XXER
HAIR CELLS




VOLUME


or


CYTOPLASM




NUCLEUSPLASMA RATIOS




Cell


7


Nucleus


28


days
1
11
213


28


0ms.


17
5


14
138


24


925
1665
1693


18


278
268
187


20


647


18
1397
1506




19
1 2.3
5.2
8.1




10
TABLE 84 Condensed
Nude us- plasma ratios of the outer hair cells




31
AVERAGE
AGE




30
AVERAGE
BODY
WEIGHT




37
AVERAGE VOLUME OF OUTER
HAIR CELLS




33
VOLUME or


CYTOPLASM




NUCLEUSPLASMA
RATIOS




Cell




Nucleus




days
1
11
213




grams
5
14
138




533
1169
1385


11


239
204
119




294


965
1266




1 1.2


4.7
10.6






17. Deiters' cells. The Deiters' cells are most delicate elements. In the literature, so far as I know, there are no exact
observations touching the growth of these cells in the papilla
spiralis, except a few data for their length. They have an






110 ANATOMICAL AND PHYSIOLOGICAL STUDIES ON


30
irregular form and consist of three parts, the phalangeal process,
cell body, and foot. The phalangeal process is thin, somewhat
crooked in the adult though it runs straight at an earlier stage.
As the boundary between this process and the cell body, we
take a line running through the supporting cup ('Stutzkelch' of
Held) parallel to the plane of the basilar membrane (fig. 10).
The cell body in its upper part is wide, including here a round
nucleus. It then becomes thin and passes over to the foot.
Thus it is almost impossible to get the true volume of the cells.
Therefore, we have determined the volume of the cell body
only, excluding that of the phalangeal process.


We think of the cell body as a cylinder having an average
diameter, which is calculated from four diameters measured at
four levels. The first level is just below the upper boundary
of the cell body, the second in the widest part, the third below at
about the middle of the cell body, and the last is at the narrowest
part near the foot. .


19
The height of the cylinder is the length of the cell body within
the limits just noted. Thus the volume obtained approximates
the value for the natural size of the cell body without the process.


In table 85 (chart 38) are given the values for the volumes of
the Deiters' cells thus computed and the diameters and volumes
of the nuclei according to age. As there are in the radial section
three rows of cells, the values given are, of course, the average
of these. At the bottom of the last column appear the ratios at
1 to 12, 1 to 20, 1 to 546, and 12 to 546 days. As we see, the
volume of the cell body increases throughout life, slowly during
the first nine days, but from twelve to twenty days very rapidly,
and then less rapidly to old age.


While the ratio from one to twelve days is 1:5.4, that from
1 to 546 days is 1:29.1, or more than five times as large.


When we consider the volumes of the cells in each turn of
the cochlea, we see that it is smallest in turn I and largest in
turn IV, though there are some exceptions before nine days
of age. Table 86 shows these relations.


The diameters of the nuclei of the cells grow, after some
fluctuations in the values at earlier stages, very slowly to old






GROWTH OF THE INNER EAR OF ALBINO RAT 111


14
age, as indicated in table 85 and chart 38. The ratios at the
bottom of the corresponding column show these relations. The
values for the volumes of the nuclei of the cells are given in the
last column. Here, also, the diameters in the upper turns tend to
be larger than in the basal turn. In table 87 are given the ratios
of the diameters of turn I to the three other turns. We see in
all the turns about the same ratios, 1:1.0.


In the literature we find but two observations on the diameters
of the nuclei of the Dieters' cells. Kolmer ('07) reports hi the
pig 5 [i, and von Ebner ( '02) gives in man 7 (x for the diameter
of the round nucleus of the cells.


28
In the rat, therefore, the diameter is larger than in these
two forms, but no significance can be attached to this difference
until correction has been made for the several techniques employed. This I am unable at present to do.


On the nucleus-plasma ratio in Deiters 1 cells. In the condensed
table 88 are given the volumes of the cell bodies and of their
nuclei together with the respective nucleus-plasma ratios. This
shows that the ratio is progressive with age. While the ratio
is at birth only 0.05, that in the oldest group is 28.3. The absolute
increase is not great at earlier stages, but by eighteen days it
is marked


25
The rapid change in the ratio is very interesting. Before
eight days of age the cells are still immature. Some time after
eight days they develop rapidly, seeming to play some important
part in the special functions of the cochlea.


On the length of Deiters' cells. To measure the length of
Deiters' cells we divide them into two parts, the upper and the
lower, by the boundary line between the cell body and the phalangeal process. The sum of these two lengths makes the total
length of the cells.


18
In table 89 are given the values for the total length and for
each part separately (chart 39). As in the volume of the cells,
we see an astonishing change in the development of the length.
The length of the cells increases through life, at earlier stages a
little, but at twelve days it becomes nearly twice as long as at nine
days. The ratios at the bottom of the last column show the
course of growth.




24


TABLE 85


The volume of Deiters' cells and the mean diameters and volumes of their respective nuclei (chart 38)






VOLUME OF THE DEITERS* CELLS




1


NUCLEI




VOLUMES








30
BODY




fit




Diameters








AGE




WEIGHT








10


Average


15




15




13






TABLE 32
I




II


Radial basal breadth of the outer pillar cells on age, based on tables 22, 28, and


29 (charts 12 and 18)
III




IV


AGE


 
Average
BODY WEIGHT
 
 
TURNS OP THE COCHLEA M




Line 13,877: Line 16,577:
IV  
IV  


diam


Average  
Average  




days




grams




Line 13,895: Line 16,595:




volume




1




5




10




9




8
eters




8
volumes




9




3




8




15




16




15




12




15




6




11




26




28
M




28
M




33
days




28
grams




9




10




26




30




30




35




30




12




13




33




38




48
1




52
5




43
278




15
232




13
237




35
256




44
251




50
7.6




48
7.5




44
7.5




20
8.1




29
7.7




35
239




40
3




49
8




49
290




43
309




25
349




36
352




35
325




42
7.0




48
7.0




48
6.9




43
7.0




50
7.0




59
180




35
6




41
11




49
425




51
395




44
495




100
364




112
420




36
7.0




45
6.5




52
6.7




54
6.6




47
6.7




150
165




183
9




36
10




45
635




49
461




54
554 423




46
518




257
6.9




137
7.0




38
7.1




44
7.1




50
7.0




53
180




46
12




366
13




181
1122




38
1369 1395




43
1569




51
1364




55
6.5




47
7.0




546
6.9




255
7.1




40
6.9




45
180




53
15




54
13




48
1466




2187 2659


Ratios 1 546 days


9546 "
3127
12546 "
20546 "




2359


1 :5.4
: 1.6
: 1.1
: 1.1


7.0




GROWTH OF THE INNER EAR OF ALBINO RAT
7.2




7.2


61


7.3




Held ('09) and others have pointed out. Yet, according to
7.2
Retzius, the outer pillar develops in the rabbit earlier than does
the inner pillar. This result seems to me very peculiar, but,
at present, I am unable to explain it.  


In table 32 (charts 12 and 13) are given the values for the
radial basal breadth of the outer pillar cells. These data are


195


ou
M.
40


20  
20  




29




3576




427115740




6171




4939




7.6




7.8




7.9




7.9




7.8




248




25
50




36
59




4088 4467 5470
4839 5970 6258




5757
6816




4695
5971




7.3
7.3




7.2
7.5




7.3


7.5




7.4
7.4




7.3
7.4




212
212




100




112




5011




6083




7137 6607




6210




6.9




7.6




7.5




7.4




7.3




212




150




183




5755 6291 7657




6750




6613




7.5




7.6




7.5




7.1




7.4




212




257




137




5776 6540 8841




8544




7425




7.4




7.8




7.9




8.0




7.8




248




366




181




6163




6908




7701




7895




7167




7.4




7.7




7.9




7.9




7.7




248


.-'


546




255


>-i


6092 6919 8028




8152




7298




7.4




7.9


^


8.0




7.7




7.7




248




Ratios 1 12 days




1 5.4




Line 14,409: Line 17,162:




1 0.9


a*






1 20 "




19.7






-^




Line 14,427: Line 17,181:




1.0








1546 "




29.1




Line 14,443: Line 17,200:




1.0








12546 "




5.4


!




Line 14,460: Line 17,221:




1.1




Line 14,465: Line 17,227:




TABLE 86 Condensed
Ratios of volumes of the Deiter's cells according to turns of the cochlea




Line 14,472: Line 17,236:




RATIOS BETWEEN TURNS




AVERAGE AGE




AVERAGE BODY




Line 14,482: Line 17,249:




WEIGHT




I-II




i-m




I-IV




days




grams




Line 14,500: Line 17,273:




1




5




1 :0.8




1 :0.9




1 :0.9




8




11




:1.0




: 1.1




: 1.1




18




21




: 1.3




: 1.7




: 1.8




213




138




: 1.1




: 1.4




: 1.3






TABLE 87 Condensed
Ratios of the diameters of the nuclei of Deilers' cells according to turns of the cochlea




Line 14,548: Line 17,343:




RATIOS BETWEEN TURNS




AVERAGE AGE




AVERAGE BODY




Line 14,558: Line 17,356:




WEIGHT




Line 14,568: Line 17,367:




I-II




I-III




'
I-IV




days




grams




Line 14,585: Line 17,388:




1




5




1 1.0




1 1.0




1 : 1.1




8




11




1.0




1.0




: 1.0




18




21




1.0




1.0




:1.0




213




138




1.0




1.1




:1.0






112






GROWTH OF THE INNER EAR OF ALBINO RAT






113






90OO






8OOO






7OOO






6000






5000






4000






3OOO






2OOO






1OOO




Line 14,666: Line 17,501:




AGE






o






25






50






50 1OO 2OO 300 4OO 5OO






Chart 38 Showing the volume of Deiters' cells and their nuclei, on the
average and according to the turns of the cochlea, table 85.
Average volume of Deiters' cells.


._. Volume of the cells in about the middle of the basal turn.


Volume of the cells in about the beginning of the middle turn.


Volume of the cells in about the middle of the middle turn.


Volume of the cells in about the beginning of the apical turn.


Average volume of nuclei of Deiters' cells, X 10.








Comparing the length of the cells according to the turn of
the cochlea, we find that after twelve days the length increases
from the base to the apex, in turn III very rapidly, in turn IV
gradually (table 90). At earlier stages the relations are irregular.






TABLE 88 Condensed
Nucleus-plasma ratios of the Deiters' cells




Line 14,700: Line 17,554:




AVERAGE VOLUMES






1




Line 14,713: Line 17,567:




VOLUME OF




NUCLEUS


AVERAGE AGE




AVERAGE BODY




Line 14,724: Line 17,582:




CYTOPLASM




PLASMA RATIOS








WEIGHT




Cell




Nucleus




.M




Line 14,744: Line 17,608:




M




M




Line 14,752: Line 17,618:




days




grams




Line 14,764: Line 17,632:




1




5




251




/
239




12




1 : 0.05




8




11




657




172




485




: 2.8




18




21




3649




221




3428




: 15.5




213




138




6483




221




6262




:28.3






TABLE 89


Length of cell body and of processus phalangeus of Deiters' cells p (chart 39)




Line 14,822: Line 17,715:




LENGTH OF THE CELL BODY




LENGTH OF THE PROCESSUS




Line 14,834: Line 17,729:




PHALANGEUS






r~




Line 14,847: Line 17,742:




TOTAL








BODY




Line 14,857: Line 17,754:




LENGTH




AGE




WEIGHT




Turns of cochlea




Turns of cochlea




OF THE




Line 14,877: Line 17,780:




CELLS




Line 14,883: Line 17,787:




I




II




III




IV




Average


G


I


:


II


DA >


ill


/c


IV




Average




Line 14,910: Line 17,820:




days




gms




Line 14,936: Line 17,848:




1




5




8




8




8




9




8




20




19




20




15




19




27




25 50 50 1OO 20O 30Q 4(X) 5QO
3




8


Chart 12 The radial basal breadth of the outer pillar cell, table 32, figure 2,
distance 9.


8




9


5O 50 1OO 2OO 30O 40O 50O


9




Chart 13 The radial basal breadth of the outer pillar cell, according to
10
the turns of the cochlea, table 32, figure 2, distance 9.


derived from tables 22, 28, and 29. At the foot of the last column
are given the ratios from 1 to 546, 9 to 546, 12 to 546, and 20
to 546 days. The values increase rapidly during the earlier
stage, but after twelve days very slowly, as the ratios show.
The breadth is, at birth, largest in the basal and smallest
in the apical turn. Very soon, however (six days), the reverse


9




62
16




17


ANATOMICAL AND PHYSIOLOGICAL STUDIES ON


18




relation appears, and the breadth increases from the base
18
to turn III relatively rapidly, but from turn III to IV slowly.
In table 33 the ratios are given in a condensed form. The radial
breadth of the outer pillar cells as given by Retzius ('84) are
as follows (table 34.)


TABLE 33 Condensed


Ratios of the radial basal breadth of the outer pillar cells on age according to
17


turns of cochlea


26




6




11




RATIOS BETWEEN TtTRNS
9




AGB
9




BODY WEIGHT
11




10




10




19




I-II
22




i-in
23




I-IV
22




days
22




grams
32




9




10




18




1
12




5
13




1 :0.9
11




1 0.8
14




1 :0.8
18




8
21




11
26




1 1.1
24




1.2
22




:1.3
36




18
12




21
13




:1.2
31




1.4
35




: 1.4
40




213
43




138
37




:1.2
18




1.4
22




: 1.4
29




25


TABLE 34
Radial basal breadth of the outer pillar cells in n (Retzius)


24




RABBIT
61




CAT
15




AOE
13




Basal
34
turn




Middle
37
turn




Apical
40
turn




Average
43
turn




Basal
39
turn




Middle
21
turn




Apical
25
turn




Average
32
turn




days
31




27




66




20




29




39




41




49




49




New-born
45




21
19
 
 
22




Line 15,188: Line 18,109:




22
30




36
34




30
27




30
72




32
25




3
36




30
42




40
43




30
51




33
51




47




17




21




30




32




25




3
72




50




59




41




45




53




53




36
48




30
16




22




30




34




7
26




65
74




66
100




60
112




64
43




36
45




Line 15,278: Line 18,214:




36
53




42
49




10
17
 


25


52


29


60


31


69


26


60


75




150




183




45




46




'
53




11
52




49




17




22




32




34




26




50
75




60
257




18
137




Line 15,338: Line 18,286:




14
46




57
56




80
58




80
51




72
18




24




28




31




25




76




366




30
181




43




48




55




55




50




17




23




29


60


32


60


25




75




546


This table shows that the breadth of the outer pillar cell increases in the rabbit and the cat continuously from birth to
old age, as I have found in the rat. Also the value is generally
smallest in the base, largest in the apex, though there are some
exceptions. The main differences between the results of Retzius
and mine is that the values in the rabbit are larger than in the
rat. This is probably due to the differences in the size of the
animals.


255




GROWTH OF THE INNER EAR OF ALBINO RAT 63
46


6. The radial distance between the habenula perforata and
the outer border of the foot of the outer pillar cell. The determination of this distance is deemed necessary not only as a datum
on growth in general, but also for its bearing on the difficult
question of the shifting of the outer pillar cell, to be discussed
later. On the other hand, this distance is identical with the
radial length of the zona arcuata of the membrana basilaris
(table 7. inner zone).


In table 35 (chart 14) are given the values for the radial
49
distance between the habenula perforata and the outer corner
of the outer pillar cell at base. At the foot of each column are
given the ratios at 1 to 12, 1 to 20, 1 to 546, and 20 to 546 days.
As table 35 shows, the distance increases continuously from birth
to old age, rapidly up to twelve days, but later gradually. Up
to three days the distance is slightly larger in the lower turns, but
after this age the relation is reversed, and this persists through life.


The increasing ratio of the distance for each turn according
to age is smallest in turn I and largest in turn IV. The ratios
for the condensed data are given in table 36. While the ratio
at birth is the same in each turn, 1:1.0, that of turn I to II is
smallest for every condensed age. Also it is to be seen that the
increase of the ratio in turn I to II is smallest and that in turns
I to IV is largest. In Retzius' work ('84) we find the following
values for this distance (table 37).


Table 37 shows that in the rabbit the growth changes are
56
similar to those in the rat, though the absolute values are somewhat
larger. As hi preceding determinations, the values for the cat
do not stand in the same relation as those for the rabbit, but
indicate precocity. Some corresponding observations by Hensen,
Bottcher, and others will be presented later.


7. The greatest height of the greater epithelial ridge (der grosse
Epithelwulst (Bottcher) s. Organon Kollikeri) resp. of the inner
supporting cells (fig. 4, G). The so-called greater epithelial ridge
is a prominence formed by high cylindrical pseudostratified cells.
It is situated axialward on the tympanic wall and continued
outward to the lesser epithelial ridge. About the fate of this
ridge there were various divergent opinions among the older


56




64
52




16


ANATOMICAL AND PHYSIOLOGICAL STUDIES ON


23




authors. Now, the view of Bottcher ( '69) is generally accepted.
30
This large prominence vanishes during development, and instead
of it a deep and wide furrow lined with low epithelium appears.
These epithelial cells become peripherally higher and finally lean


TABLE 35


Radial distance between habenula perforata and the outer corner of the outer pillar
33
cells at base on age (chart 14)- For the average values
see the third column in table 9




26


AGE


78


BODY WEIGHT


Ratios 1 12 days


TURNS OF TBE COCHLEA M




I


1 :4.6


II




III




IV




Average




days


1 :1.3


yrams


1 :2.3




1 20 "








:5.6




Line 15,509: Line 18,427:




1




5




50


: 1.4


50


:2.7


48


1546 "


48




49


:6.5


3




8




63




65




64


:1.4


58


:2.9


63


12546 '"


6




11


: 1.4


64




73




86




86




77


:1.1


9


: 1.3


10




70
When we consider the length of the cell body, it is remarkable
that the increase takes place so rapidly. While at 1 day it
measures only 8 (x and at nine days only 14 ji, it increases very
suddenly at twelve days of age, and after that slowly but continuously (table 89).


TABLE 90
Total length of Deiters' cells according to turns of the cochlea (chart 39)


76




86
AGB




86
BOOT WEIGHT




80
TURNS OF THE COCHLEA




12
I




13
II




69
III




83
IV




98
days




100
grams




88




15




13




70




84
1




98
5




95
28




87
27




20
28




29
24




71
3




81
8




96
24




98
26




87
27




25
28




36
6




71
11




86
28




95
31
 


34


97


32


87


9


50


10


59


36


69


33


83


39


96


35


102


12


88


13


100


49


112


57


73


69


88


68


101


15


106


13


92


55


150


62


183


72


73


74


89


20


98


29


107


58


92


64


257


79


137


S3


76


25


87


36


98


59


107


64


92


81


366


83


181


50


76


59


89


57


100


67


107


83


93


87


546


100


255


112


78


60


89


70


104


83


106


84


94


150




Ratios 1 12 days
183 '
1 20 "
1546 "
20546 "




62


1.4
1.4
1.6
1.1


68




: 1.7
85
: 1.6
 
:1.8
: 1.1


86


257


1 -2.0
:2.0
:2.2


137




1 :2.1
61
:2.0
:2.2
: 1.1




70


: 1.8
: 1.8
: 1.9
: 1.1


84




100
89




366


80


181




Line 15,856: Line 18,752:




71


40


84




AG^E DAYSH
87




546


O


255




25 5O 50 too 2OO 3OO 40O 500
62




72


Chart 14 The radial distance between the habenula perforata and the
outer corner of the outer pillar cell at base, table 35, figure 2, distance 5.


86




GROWTH OF THE INNER EAR OF ALBINO RAT
89






65
80
M
60


40


20
n


on the inner supporting cells, which are termed ' Grenzzellen '
by Held ('02). The latter belong, of course, to this ridge, since
the inner hair cell marks the outmost row in the ridge. The
'Grenzzellen' of Held, however, are different from other high
cylindrical cells in the ridge, as they have a very intimate relation
with the ' Phalangenzellen ' of Held, stand with their bases just


TABLE 36 Condensed


Ratios of the radial distance between the habentda perforata and the outer corner
'''Chart 39''' The length of Deiters' cells, tables 89 and 90.
of the outer pillar cells at base on age






500






Total length of the cells.
Length of the cell bodies.
Length of processus phalangeus.


RATIOS BETWEEN TURNS


In the ratios at the bottom of table 89 this is shown very
evidently and in each turn this relation is to be seen.


AVERAGE AGE
For the length of the phalangeal process the story is quite
different. It increases from birth to twelve days a little; at
fifteen days it reaches full size, and then holds its value (table 89) .
After three days the length is smallest in turn I and largest in
turn IV. This relation lasts to old age.


Comparing the growth of the length of the cell body and
phalangeal process, there is a large difference between them.
While the length in the phalangeal process is at birth over twice
that of the cell body, at 546 days it is only half that of the cell


AVERAGE BODY
TABLE 91


Total length of Deiters' cells in fj, (Retzius)






AGE




WEIGHT




I-II
RABBIT




i-in
CAT




I-IV




days
Basal




grams
Middle




Apical




Average




Basal




1
Middle




5
Apical




1 :1.0
Average




1 :1.0




1 :1.0
turn




8




11




: 1.1
New-born




:1.3
48




: 1.2
70




18
60




21
59




:1.2
45




: 1.4
65




: 1.4
48




213
53




138
2




: 1.2
45




: 1.3
66




: 1.4
54




55


TABLE 37


Radial distance between habenula perforata and the outer corner of the outer pillar
cells at base in n (Retzius)






RABBIT




CAT




Age




Basal
1




Middle
3




Apical




Average




Basal




Middle




Apical




Average




45




turn
60




turn




turn




turn




turn
7




turn
80




turn
90




turn
75




days
82




49




69




63




60




10




98




100




114




New-born
104




75




80




75




77




105




105




120
11




110




2




80




90




100




90




75




90




45




70




14




84




3
105




112




100




Line 16,156: Line 19,055:




80




120




30




Line 16,167: Line 19,065:




54


7


75


100


70


115


66


107




107
body. Thus the increase of the total length of Deiters' cells
is due chiefly to the increase in the length of the cell body.


Retzius ('84) gives the length of Deiters' cells in the rabbit
and cat as in table 91.


78
Table 91 shows that in both the rabbit and the cat the length
at all ages is greater, and especially at the earlier stage is twice
as great, as in the rat. In the rabbit there is a rapid increase
in length between seven and ten days. For the cat the values
are smaller, nearer those of the rat, and show less change between
birth and thirty days.


18. Summary and discussion. Using the foregoing data on
the form and measurements of the elements of the cochlear
duct, I desire here to summarize the results and to discuss the
consequent changes in the form of the organ of Corti (table 92).


110


We have already noted that at birth the greater epithelial
ridge constitutes the main part of the tympanic wall, and the
lesser epithelial ridge, from which arises later the most important
organ, is represented by a small and undeveloped prominence.
With age this greater ridge disappears gradually and is transformed into a furrow lined with low epithelial cells, the sulcus
spiralis internus (Waldeyer). These changes appear first at the
base and then pass gradually to the upper turns. In the lesser
ridge also there are important developmental changes. At first
the hair cells and pillar cells grow, and just before the special
function appears, striking changes are seen in Deiters' and
Hensen's cells. These increase, especially in their length, very
rapidly.


120
Thus the papilla spiralis, which hitherto had its highest
 
point at the summit of the arch of Corti, shows a remarkable
 
change of form, as the outer part of the papilla increases its
103
height, so that finally Hensen's cells mark the highest point
 
in the papilla. The surface then ceases to be parallel to the
basilar membrane, and slopes inward, making with the basilar
membrane an acute angle opening outward. At the same time
the papilla spiralis appears to be shifted inward i.e., towards
the axis.


10
Kolliker has described how the cells, from which the pillars or
rods of Corti arise, at first stand nearly parallel, but later separate
at their base. He thought that this "von einem Langenwachstum (?) der Zellen selbst oder ihrer Grundlage, der Membrana basilaris, abhiingen kann. "


Hensen ('63) first studied this interesting problem in the ox
and found it to depend on a peculiar process. He regarded the
inward migration as taking place chiefly in the inner pillar cell.
The outer pillar cell in the upper turn moves somewhat outward ;
in the base, however, inward. Moreover, the outer pillar cell
increases its length during the development of the papilla much
more than the inner does. Thus the summit of the arch of Corti
and therefore the papilla spiralis shifts inward on the basilar
membrane.


100




120




129


CO 1C CO O 1C CO


116


o^cot^coco^^




GO 1C CO




CO




Os Os Os




-f




1


v


Tf 1C rH CO CO t^.


11
1C CO CO CO CO T}<
i-l i-l rH




rH OS rH O
rH rH CO




CO CO OS


rH rH CO




CO




rH CD t- 1 1 1 1 1C




1C ^ 1C




41


120


1


129




108




119




14




106




140




129
O CO OS CO O b


CO CO CO OO


125


? 1 ?!




;O




O




^H CO








> *)< 1C




1C


30


O OS OS




t^




Jj




O rH 1C CO t>- CO




CO OS CO OS




CO CO OS




re


85




120


rH CO


120




108


;>. rH rH




outward from the habenula perforata and serve to support the
1C
inner hair cell as Deiters' cells support the outer hair cells.


Thus the greater ridge includes in its prominence three kinds
of cells, the high cylindrical cells, the 'Grenzzellen' of Held and
the inner hair cell.


The greatest height of this ridge is not situated at a fixed
CO * 1C
point, but first lies somewhat outward from the middle part and




*


66






ANATOMICAL AND PHYSIOLOGICAL STUDIES ON


1 < rH rH CO CO ^




after the furrow appears, passes outward towards the inner
i 1 rH rH
supporting cells. Thus the greater ridge decreases in thickness
from birth to nine days of age, then increases gradually to twenty
days. After twenty-five days the values diminish again very
slowly but continuously.


In table 38 (charts 15 and 16) are given the values of the greatest
height of the greater epithelial ridge from the basilar membrane


TABLE 38
rH rH CO


Greatest height of the greater epithelial ridge (resp. of the inner supporting cells)


on age (charts 15 and 16)




Line 16,343: Line 19,284:




Bodv wcifitlitj




TURNS OF COCHLEA M




Line 16,353: Line 19,292:




I




II


1


III


O OS 1C C O CO


IV


CO 00 O OS C-i CO OS CO


Average
height


o


days
1


1C 00
rH 1C


grams
5




68


CO 1C -^
f rH rH


65


00
1C


66


CO CO CO


63
CO 1C CO




66
,>




3
i




8
CD CO "*!
rH rH rH




49
rH rH rH




49
rH i 1 CO




56




57




53




6




11




40




40




41




40
T3~




40




9




10




36




40




41
-c




42
1C CO 1C 1C 1C *C




40




12




13


Radial distance betw
habenula perforata
Breadth of membran!
(table 9)


38


Breadth of membran
(table 4)


41


Thickness (table 4)


48


jj


53
1


|i


45
/. -_


3


15


From hab. perf. to 01
Distance between thi


13


5
5


44
-M


c/.


46
s




52
O & & g ^J - J3 X! -r=


iiilliiill


58
^ " S S^


O W (JrJ W


50




20
GROWTH OF THE INNER EAR OF ALBINO RAT




29


119


50




53
O C* O5 O b CO


oo t^ co co t o co m coo ^w


63
<NW CO t GO 1-1 i-i CJ 1-1




66


^"00 I-H <M 1-1 O


58
-H t* CO CO C5 <N U3 CO OOO ^i-J
CO C<l COt>-t>- i-i ~*^H C^^H




25


COl>-COCO OOCOO CO ^00 CO(N
COC^ lOCOCO-^'H (Ni-i


36




51
CO t> CO CO
CO W




51


O -H ~4


63
O CO "5




63


00 O
O CO 00


57




50
o oo oo


CO W


59




50
CD 10


CO 00


50




59
t^ 00 C^J 00
(N <N




63


^ M O
(N CO IM


56




100
O O




112


(N 00 CO -H


48
!-H (N i-H




49


o> o


59




63
^H 00




55


O 00 O> t> "* t^ O
C iH CO d CO


150




183
O -H


(N -H


47




49




56
Is
Is




61


a


53




257
JS




137
_M ^S ^W -5 o,, W X


13131 ^1


47
IH ^^ *- ^"'S.'M -S ""


'3 2 '3 j>3 B" *8


51
fl? fl C? C3 *J? o3 ^5 rt


.9050 a^^a


56
<_ 5 P ,_ ~ oC.^


o g o S o g g^
c" rt a^os -jfja -g-g


62




54
5 '53 o *S
.2,213.0.2-3


a p V o fl


366
1 1 i IN


I'Mg 2? W
V v Ja V V


181
i- S || a a
L|SSl3S




46


HI C~" WH < C/2


49




57
120


Bottcher ( '69. 72) disagreed with Hensen, though he has confirmed, as did Middendorp ('67), the striking inward spreading
of the base of the inner pillar cell.


60
Gottstein] ( 72) held that the inner pillar cell does not move
inward, but that the increase in the length of the labium tympanicum may explain the peculiar approach of the habenula
perforata to the arch of Corti.


Retzius ('84) agreed in general with Hensen 's assertion that
in the course of development the surface of the sense organ
comes to lie under the basal surface of the membrana tectoria.
He thought that this change of position is brought about "weniger in dem Verhalten der Pfeilerzellen, sondern vor allem in
dem starken Wachstum der Deitersschen Zellen und der von
aussen andriickenden Hensenschen Stiitzzellen, ' and that,
further, "vielleicht die Membrana tectoria selbst durch eigenes
Wachstum und durch Vergrosserung des Limbus mit seinem
Vorspriingen" contributes to this.


54
Held ('09) agrees with Hensen on the whole.


Prentiss ('13, p. 450) denies the wandering of the spiral organ
as follows: ''There is no necessity for, and my preparations
afford no proof of, an inward shifting of the spiral organ and
a consequent displacement of the membrana tectoria "


546
Hardesty ('15, pp. 60 and 61) discussed the relative position
 
of the spiral organ with reference to the basal surface of the
 
tectorial membrane and says " the developed spiral organ acquires
255
its position well under the basal surface of the tectorial membrane
 
almost entirely by being carried axisward during the completion
 
of the membrane." "In the apical turn, where these changes
44
are greatest, the hair cells of the organ may be carried axisward
a distance nearly half the width of the membrane. The upgrowth
of the outer supporting cells also forces axisward the apical
ends of the elements of the spiral organ and in this way contributes a small part to the shift in the relative position of the
hair cells. A slight increase in width of the vestibular lip of
the spiral limbus may contribute a still smaller part by extending
the membrane outward."




50


GROWTH OF THE INNER EAR OF ALBINO RAT 121


56
I obtained from the measurements given in the tables the
following results concerning the position of the papilla spiralis
under the basal surface of the tectorial membrane.


As already stated, since the habenula perforata may be considered after birth as a punctum fixum (Hensen), it is found
that the inner pillar cell shifts inward at its inner basal corner
during the earlier stage of life. At six days of age it almost
always reaches the habenula perforata in the basal turn, though
not yet in the apical. At nine days there is no distance between
the- habenula perforata and the inner corner of the inner pillar
cell.


60
Gottstein's assumption (no measurements) that the labium
tympanicum grows outward and approaches to the arch of Corti
is not applicable to the rat, as shown by my tables.


The outer pillar cell also moves outward in all the turns
through life, but only slightly after nine days. This result does
not agree with that of Hensen ('63), who found in the ox the
outer pillar cell to move inward a little at the base, not at all
in the middle turn and outward at the apex. Bottcher 's outward
movement of the outer pillar cell at the hamulus in the cat is
90 y. and much larger than in the rat.


53
Contrary to Hensen, Retzius ('84) also finds in the rabbit an
outward movement of the base of the outer pillar cell throughout
all the turns. On the other hand, during the earlier stages of
development, the top of the arch of Corti moves outward from
the labium vestibulare through the outward pressure of the
greater epithelial ridge. At this stage the main part of the
membrana tectoria does not yet reach to the sense cells, though
the part produced from the lesser epithelial ridge spans the
spiral organ and connects with the outer part of the papilla.


After nine days of age the condition of the organ is quite
different. The most remarkable anatomical changes from the
earlier condition are the rapid increase in the length of the outer
pillar cells, in the height of the pillar cells above the basilar
membrane, in the height of the papilla spiralis at the third series
of the outer hair cells, in the height of Deiters' cells, and in the
height of Hensen 's supporting cells. Also the tunnel of Corti
appears.


Ratios 1 9 days 1:0.6


The greater epithelial ridge has already disappeared in large
part and been replaced by a furrow. Pressure displacement
of tissue in the direction of the least resistance is common in
organogenesis. Thus the inner pillar cell is subject to pressure
by the rapid growth of the outward lying and greater part of
the papilla spiralis and moves in the direction of the least resistance, therefore inward; the head most and the base not at all.
As shown in table 44, the rapid decrease in the radial distance
between the labium vestibulare and the head of the inner pillar
cell is very evident. The arch of Corti changes its form, now
inclining inward, instead of outward as heretofore. The lamina
reticularis runs not parallel to the basilar membrane, but ascends
outward. The tunnel of Corti also changes more or less its form.
Nuel 's space now appears possibly as a result of this displacement
of the papilla spiralis. Thus we see a change in the position
of the sense organ with reference to the membrana tectoria.


12 20 " :1.3
With the inward shifting of the papilla, the hair cells come
under the basal surface of the membrana tectoria. It is probable
that the increase of the relative length of the membrane also
takes part in this, since the increase in the breadth of the inner
zone of the membrana tectoria from one to twelve days is as
1:3.4 (table 4), while the increase in the breadth of the basilar
membrane is as 1:0.5 during the same interval (table 7).  


Prentiss' ('13) statement that an inward shifting of the papilla
spiralis and a consequent displacement of the membrana tectoria
does not take place (in the pig) is not applicable to the rat.


12546 " :1.2
In the rat the labium vestibulare and the inner edge of the
head of the inner pillar cell are also two definite points in the
same sense, and using them we see an inward shifting of the
organ of Corti. I imagine that his observation may have misled
him, since the tectorial membrane arises in his preparations
from both greater and lesser epithelial ridges, and from the
earlier stages covers with its outer part the papilla spiralis.
Thus the shifting of the organ inward does not necessitate a
change in the position of the papilla with reference to the membrane. In his study of the tectorial membrane in the same
animal (pig) , Hardesty ( ' 13) describes a large displacement of the
papilla spiralis inward.  


According to him, the shifting of the organ consists of, 1, the
moving axisward of the organ itself, and this constitutes the
main shift; 2, the upgrowth of the outer supporting cells, and
this contributes a small part to the shift, and, 3, a slight increase
of the vestibular lip of the spiral limbus which may contribute
a still smaller part. The relation in the rat, however, is different.
The moving inward of the papilla itself is not seen in the rat.
In the earlier stages the inner basal corner of the inner pillar
cell alone shifts inward and reaches the habenula perforata.
On the other hand, the outer pillar cell moves outward and
the head of the inner pillar cell also, at earlier stages, towards
the cells of Hensen. Therefore, during the earlier stages the
arch of Corti moves rather outward, owing to the pressure of
the growth of the greater epithelial ridge. Since the habenula
perforata is to be regarded as a fixed point, the inward displacement of the head of the arch of Corti and of the papilla spiralis
is not due to the active shifting inward of the organ itself, as
Hardesty ('15) thinks, but to the disappearance of the greater
ridge and the passive pressure exerted by the upgrowth of the
outer pillar cells and Deiters' and Hensen 's cells. The vestibular
lip of the spiral lamina and the tectorial membrane itself both
increase in their length a little, and these increases play some
part in the change of the position of the papilla spiralis with
reference to the basal surface of the tectorial membrane.


20546 " :0.9
The membrana basilaris is not concerned with the moving
 
inward of the organ. It increases its length with age in all the
turns, but we do not find the change in the position of the feet
of the pillar cells on the membrane in such a sense that the
feet move inward on it.


1546 " :0.8
Thus the shifting of the papilla spiralis inward in the rat
during the development takes place rather in the manner described by Retzius.  


Hardesty ('15) states that in the apical turn of the cochlea the
organ may be moved axisward a distance equal to about half
the maximum width of the greater epithelial ridge, the maximum
width of the ridge representing approximately the width of the
outspanning zone of the membrane produced upon it.




through the summit of the supporting cells, according to age.
At the bottom of the last column is given the ratio at 1 to 9,
1 to 546, 12 to 20, 12 to 546, and 20 to 546 days of age.


The values in turn I are at birth the largest, but at three
No other author reports such a high degree of the inward
days the relation is reversed and remains so in the later age
shifting of the organ. I have not studied the pig, but in the
groups. Table 39 shows this relation from the condensed data.  
rat I get the average distance between the labium vestibulare
and the inner edge of the head of the inner pillar cell as follows
(table 93).  


Retzius ('84) gives in the rabbit and cat the following values
TABLE 93
(table 40).


Average distance between the labium vestibulare and the inner edge of the inner
pillar cell in n (albino rat)




GROWTH OF THE INNER EAR OF ALBINO RAT


AGE




67
BODY WEIGHT




TURNS OF COCHLEA


In the rabbit the values decrease from birth till ten days,
then increase; therefore, they agree in general with my results


I




50
II
40
30




III


;


IV




25
Average




days


50 50 10O 20O 30O 40O 500


Chart 15 The greatest height of the greater epithelial ridge (resp. of the
grams
inner supporting cells) table 38, figures 4 to 12.






70
44


60


5O
40
30






s






o


(1) 5
(2) 154
Difference betw
1 and 2




25
9
102
een age groups




94


50
63
31




124
100
24


50 IOO 20O 3OO 4OO 500


1,54
134
20




Chart 16 The greatest height of the greater epithelial ridge (resp. of the
165
inner supporting cells) arranged according to the turns of the cochlea, table 38,
figures 4 to 12.


on the rat, while in the cat they diminish from birth till thirty
148
days though irregularly.
17


The absolute values are greater for the rabbit than for the
rat during the earlier stage, but afterwards they are similar.


23




68


Therefore, in the rat the organ moves inward on the average
of 23 [A; that is, in the ratio of 1:0.16 of the maximum distance
between these two points. It may be noted that the difference
in this table is not the same in the several turns, but diminishes
from base to apex a relation which is the reverse of that reported
by Hardesty ('15) in the pig. I have no explanation for these
differences except their possible dependence on the different
animals used.


==C. On the growth of the largest nerve cells in the ganglion spirale==


In the cat the early data give values similar to those for the rat,
Observations. For the present studies the fourteen age groups
but the later values are lower.  
used in the previous observations on the growth of the tympanic
wall of the cochlear duct were employed. In order to see the
relation between the growth of the papilla spiralis and the cells
of the ganglion spirale, both studies were made on the same
sections. In addition, however, I made cross-sections of the
cochlea (i.e., at right angles to the axis) in several age groups
to follow the growth and the changes in the form of the nerve
cells as they appear in this plane. The data for the animals
thus used are given in table 94.  


Bottcher's observations ('69) on the cat, calf, and sheep also
give larger values than mine. In the cat the greater ridge has
an average height of 75 [x and in both the others of 90 \L. Therefore,
even in the same animal (cat) there are large differences in the
data presented by different authors.


TABLE 39 Condensed
For the measurement of the nerve cells a Zeiss system was used
with a micrometer eyepiece, having each division equal to 2jx.
Since we have in the radial vertical section of the cochlea of the
rat at least four turns, there are four cell groups available in
each section (fig. 3). The ten largest cells in each ganglion
were measured, and thus a total of forty cells in a section were
taken for the measurement of the nucleus and the cell.


Ratois of the greatest height of the greater epithelial ridge (resp. of the inner supporting cells) according to the turns of the cochlea on age
We used, as stated, four cochleas in each age group, so that
160 cells were measured for each age. Also in the cross-sections
the four nearly corresponding turns were used for the measure-
ments, selecting the ten largest cells in each turn.


TABLE 04
Data on rals used for cross-sections of the cochlea ganglion spirale




Average age


AGE


Average body
weight


BOOT WEIGHT


RATIOS BETWEEB TURNS


BODY LENGTH


I-II


BEX


i-in


8IDE


I-IV
 
HEARING




Line 16,821: Line 19,907:




1




5
15




1 :1.0
20




1 1.0
84




1 :0.9
(?




8
L.




11
Prompt response




: 1.0
20




1.1
27




: 1.2
93




18
d"




21
L.




:1.1




1.2
25




:1.3
39




213
114




138
P




:1.0
L.  




1.2




:1.3
100




95


TABLE 40


152




Greatest height of the greater epithelial ridge measured through the inner supporting
<?


cells, in p. (Retzius)


R.




RABBIT




CAT
150




Age
169


days


192


Basal
turn


9


Middle
turn


L.


Apical
turn




Average
turn


371


Basal
turn


220


Middle
turn


206


Apical
turn


c?


Average
turn


L.


New-born




78




99
In the measurement of the cell bodies the two maximum
diameters at right angles to each other were determined, and
also the two corresponding diameters for the nuclei.


Here it is to be noted that the expressions turn I, II, III,
and IV are used in the same sense as in the earlier chapters.


90
In table 95 (chart 40) are given the values for the average
diameters of the cell bodies and their nuclei in the ganglion
spirale in the radial vertical section according to fourteen age
groups. Under 'cell body, diameter,' the first column gives the
long, the second the short, and the third the computed diameter;
i.e., the square root of their products. These last values ap-
proximate the mean diameters of the nerve cells. At the foot
of the third column are given the ratios from 1 to 20, 1 to 546,
and 20 to 546 days. The values for the diameters of the nurlei
are similarly given and also the ratios.


As the tables and charts show, the diameters of the cell bodies
and also of their nuclei are largest at twenty days of age. After
that age they diminish, gradually. While the ratio for one to
twenty days is 1:1.7 in the cell bodies and 1:1.3 in the nuclei,
that for 1 to 546 days is 1:1.6 and 1:1.2, respectively.


89
TABLE 95


Diameters of the cell bodies and their nuclei in the ganglion spirale (radial-vertica I


45
section) (chart 40)




75




6S




63




2


Diameters in M


60




90




90




80


Cell body




Nucleus




AGE




BOOT




BODY




Line 16,989: Line 20,078:




3






WEIGHT




LENGTH




Line 17,004: Line 20,094:




40




84




Line 17,016: Line 20,104:




7


Long


51


Short


68


Computed


63


Long


61


Short


40


Computed


54


days


63


grams


52


mm.


10




36




54




56




49




Line 17,061: Line 20,144:




1




5




48




11.0




10.0


11


10.5




8.2




7.6




7.9




3




8




56


50


12.0


58


11.1


66


11.5


58


8.2


14


7.8


51


8.0


51


6


51


11


51


63




13.6




12.3




12.9




8.8




8.1




8.4


30


9




10




58




14.3




12.8




13.6




8.9


30


.  
8.2




45
8.5




45
12




40
13




70


Gottstein ('72) thinks that the greater epithelial ridge does
not diminish its height for some time after birth, but through
the outward development of the labium tympanicum, and in
addition to this through the growth of the labium vestibulare,
the sulcus spiralis internus arises. He does not give measurements.


14.6




GROWTH OF THE INNER EAR OF ALBINO RAT 69
13.1


His idea was strongly opposed by Bottcher ( 72) and my results
are also opposed to Gottstein's view.


8. The radial distance between the labium vestibulare and the
13.8  
habenula perforata. The purpose of this measurement is to
determine how the habenula perforata stands in relation to its
surroundings during the development of the cochlea. The measurements of this distance is difficult. During the earlier stages,
the labium vestibulare is quite undeveloped, especially in the
upper turns. At birth we see on the inner surface of the greater
epithelial ridge a small prominence under which the epithelial
cells are short and pressed together so that the nuclei seem to be
arranged in several rows (fig. 4). This appearance is due to the
invasion of the subjacent connective tissue into the epithelium.


Thus the vestibular lip arises. We do not see a furrow at this
time and cannot use the top of the furrow as a point for measuring
as did Hensen ('63) in the ox and Bottcher ('69); in the embryo cat). To the measure the distance between the insertion of
Reissner's membrane and the habenula perforata has no meaning
for my purpose, because the length of the limbus laminae spiralis
changes with age.


Thus I have measured the distance between the small epithelial
8.7
prominence on the axial side of the greater ridge, corresponding
to the edge of the labium vestibulare, and the habenula perforata.  


In table 41 (charts 17 and 18) are given the -values of the radial
distance between the labium vestibulare and the habenula
perforata. At the foot of the last column are given the ratios
from 1 to 546, 9 to 546, and 20 to 546 days. As we see, the
values are a little bit smaller at the earlier stage. After nine
days they are almost the same in every stage. The small differences at the earlier and later stages are probably due to the
retarded development of the labium vestibulare.


When we consider the values for this distance in each turn,
8.2
it is evident that these increase from base to apex. In the condensed table 42 this relation is shown.  


Hensen ('63) finds that the distance from the top of the furrow
to the habenula perforata is in the fetal calf and in the ox the


8.5




70
15




13


ANATOMICAL AND PHYSIOLOGICAL STUDIES ON


75




same, 255 [x. He considers the holes of the habenula as a ' punctum
15.7
fixum. ' Bottcher ('69, 72) agrees with Hensen and gets in the
cat embryo and the adult cat the following values (table 43).  


TABLE 41


Radial distance between the labium veslibulare and the habenula perforata on age
14.1


(charts 17 and 18)


14.9




AGE
9.1




BODY WEIGHT
8.4




TURNS OP THE COCHLEA M
8.7




I
20




II
29




III
95




IV
19.0




Average
17.3




days
18.1




grams
10.3




10.0




10.2




25




36




104




1
18.5




5
16.9




100
17.7




108
10.2




120
9.9




130
10.1




115
50




3
59




8
125




80
18.5




110
16.6




130
17.5




137
10.3




114
9.7




6
10.0




11
100




82
112




105
159




135
18.1




137
15.7




115
16.9




9  
9.8




10
9.2




83
9.5




108
150




137
183




145
190




118
18.2




12
15.3




13
16.7




80
9.6




102
8.8




139
9.2




148
257




117
137




15
175




13
18.5




82
15.3




107
16.8




144
9.9




157
9.4




122
9.6




20
366




29
181




84
191




106
18.6




146
15.3




153
16.9




122
9.8




25
9.0




36
9.4




82
546




105
255




147
213




150
18.6




121
15.3




50
16.9




59
9.7




82
9.0




104
9.4




137
Ratios




147




118




100




112




80




103
120 days




151




154
1:1.7




122




150




183
1:1.3




80
1546 "




107




141
:1.6




144




118




257
:1.2




137
20546 "




83




105
:0.9




143




150




120
:0.9




366


In table 96 (chart 41) are a series of computed diameters
of the cell bodies and of their nuclei according to the turns of the
cochlea. At the bottom of each column are given the ratios
from 1 to 20, 1 to 546, and 20 to 546 days. Determining the
ratios for each column, it appears that in general the diameters
of the cell bodies and their nuclei are largest at twenty days
throughout all the turns. This increase is very considerable from
fifteen to twenty days. Then they decrease very slowly till
546 days.


181




79
GROWTH OF THE INNER EAR OF ALBINO RAT




105


127


135




149
Table 97 enables us to compare the ratios in the diameters of
the cell bodies and their nuclei in turns I, II, III, and IV in the
condensed age groups. In both the cell bodies and their nuclei
the ratios become slightly larger in passing from the basal toward
the apical turn, except in the one day group, which it reversed.


On the comparison of the diameters of the nerve cell bodies
and their nuclei in the ganglion spirale according to sex. For
this comparison seven age groups were used. In each age group
we have sometimes one, sometimes two cochleas of the same sex.


117




546


Chart 40 Showing the computed diameter of the largest cell bodies and their
nuclei from the ganglion spirale, table 95.
----- Diameters of the cell bodies.
---------- Diameters of the nuclei.


255
In the latter case the average value is recorded. In table 98
are given the values for these diameters, and it is plain that
there is no significant difference in these values according to sex.
On the comparison of the diameters of the nerve cell bodies
and their nuclei in the ganglion spirale according to side. For
this purpose fourteen age groups were employed. In most
cases two cochleas from the same side were used in each age group.
In these cases the average value is recorded. Table 99 shows the
values for the diameters of the cell bodies and their nuclei accord-
ing to side, but reveals no evident difference in this character.




79
On the morphological changes in the ganglion cells during
growth. As my sections could not be stained with thionine, my
observations on the Nissl bodies are incomplete, yet the slides
stained with Heidenhain's iron haematoxylin and van Gieson's
stain, as well as by haematoxylin and eosin, were helpful here.




105


TABLE 96


143




150
Computed diameters of the cell bodies and their nuclei in the ganglion spirale
according to the turns of the cochlea (chart 41 )




119


AGE


days


Ratios 1 546 days


9546 "
BODY
20546 "
WEIGHT


gms




1.0
TURNS OF THE COCHLEA
1.0
1.0




Computed diameters M


TABLE 42 Condensed


I




Ratios of the radial distance between the labium vestibulare and the habenula
II
perforata according to turns of the cochlea




in




IV




Cell
body


RATIOS BETWEEN TURNS


Nucleus


AVEKAGE AGE


Cell
body


WEIGHT


Nucleus


I-II


Cell
body


I-II I


Nucleus


I-IV


Cell
body


days


Nucleus


grams


1




5




11.0




8.0


1


10.8


5


8.2


1 1.1


10.4


1 1.2


8.0


1 1.3


9.6


5


7.4


10


3


1.3


8


1.6


11.5


1.8


7.9


141


11.5


93


7.9


1.3


11.7


1.7


8.0


1.8


11.3




Comparing the results of both Hensen and Bottcher with
8.1
my own, the values obtained by Hensen are large, as would
be expected in the larger animal. The cat and rat however,
give similar values. We conclude, therefore, that broadly speak




GROWTH OF THE INNER EAR OF ALBINO RAT
6




11


71


12.9




ing, the habenula perforata is to be considered as a 'punctum fixurn, 'at least after birth.  
8.4


9. The radial distance be'.ween the labium vestibulare and the
inner edge of the head of the inner pillar cell To measure the


12.6




140
8.2




13.0


120


8.5




1OO
13.3




8.6


AGE DAYS


9


25


10




50
13.4




8.4


50 1OO 2OO 3OO 40O 500


Chart 17 The radial distance between labium vestibulare and the habenula
13.4
perforata, table 41, figure 10.  




8.5


i cr\


13.6




8.6




13.7




8.6




12




13




13.6




8.1




13.5




8.1




13.8




8.6




14.7




9.0




15




13




14.8




8.6




15.0




8.6




14.6




8.6




15.0




9.2




20




29




17.6




10.0




17.6




9.9




18.1




10.2




19.0




10.4


loO


25




36




16.9




9.9




17.6




10.0




17.6




10.1




18.4




10.3




50




59




17.2




9.7




17.2




9.7




17.6




10.0




17.9




10.1




100




112




16.9




9.6




16.9




9.4




16.3




9.3




16.9




9.6




150




183




16.9




9.3


it


16.3




9.0




16.6




9.1


/


17.0




9.1


'


257




137




16.7




9.6




16.7




9.4




16.9




9.7




17.0




9.7




366




181




16.7




9.3




16.4




9.2




16.7




9.1




17.7




9.7




546 255
Ratios 1 20 day*
1546 "
20546 "




15.8
1:1 .6




9.2
1:1.3




16.3
1:1.6




9.4
1:12




16.9
1:1.7




9.4
1:1.3




17.4
1:2 .0




9.5
1:14




1 5




1 2




a
1 5




: 1 2




: _
1 7




1 2




*
1 8




: 1 3




:1.0




- v
:0.9




:0.r-




: 1.0




:0.?'




/
:0.9




^
:O.S




: 0.9






TABLE 07 Condensed
Ratios of the diameters of the cells and nuclei of the ganglion spirale


.




AVERAGE
AGE




AVERAGE
BODY
WEIGHT




RATIOS BETWEEN TURNS




I-II




l-lll




I-IV




Cell body




Nucleus




Cell body




Nucleus




Cell body




Nucleus




days


1


8
18
13




grams
5
11
21
138




1 :0.98
:0.99
: 1.01
:0.99




1: 1.25
: 1.00
: 1.00
:0 99




1:0-95
: 1.01
: 1.01
: i.OI




/
1 : 1 . 00
: 1.02
: 1.01
: 1 . 00




1 : . 87
: 1.03
1.04
: 1.04




1 :0.93
: 1.05
: 1 . 05
: 1.02






GROWTH OF THE INNER EAR OF ALBINO RAT


>




129






19
M
18


17
16
15
14
13
12






10
9






Si;






DAYSi-


i i




\




Line 18,038: Line 21,320:




25


_




50






, oo 2OO 3OO 4OO






Chart 41 'The computed diameter of the largest cell bodies and of their
nuclei from the ganglion spirale, according to the turns of the cochlea, table 96.
Upper graphs: diameters of the coll bodies. Lower graphs: diameters of the
nuclei of the cells.






130






Figure 13 illustrates semidiagrammatically the nerve cells
in the spiral ganglion of the albino rat at 1 day and at 20 and 366
days.


The body of the ganglion cells at birth is small and has the
characteristic fetal form. The cytoplasm is homogeneous and
scanty and the Nissl bodies are not yet seen. The nucleus forms






TABLE 98






Comparison according to sex of the diameters of the cell bodies and the nuclei in


the ganglion spirale






AGE




BODY WEIGHT


140


NO. OF RAT8




SEX


A


COMPUTED DIAMETERS M


it


Cell


*


Nucleus




days




grams




Line 18,094: Line 21,397:




k


3




7




1


;


&




11.4




8.0








8




1




9




11.4




8.0




6


^


- !
11




2




tf




_
13.1




8.5








10




2




9




12.8




8.4


:


9




10




2




c?




13.6




8.5








9




2




9




13.5




8.6




12




14




2




c? 1




13.7




8.5








12




2 .




9




13.9




8.4




100




146




. 1




<?




17.2




9.6








103




1




9


/


16.9




9.4




150




189




1




d 1




16.5




9.1








154




1




9




17.1




9.1




365




205




1




d 1




16.3




9.0








170




1




9




16.7




9.1




Average male




14.5




8.7




Average f e male




14.6




8.7




Male larger than female




3


/


3




Female larger than male




3




2




Male and female equal




1




2






the greater part of the cell. The chroma tin is not yet well
differentiated, and the so-called 'Kernfaden' are not visible.


The sharply marked nucleolus is in most cases in the central
position, but sometimes located peripherally.


The cytoplasm matures rapidly. At six days the Nissl bodies
appear, though they are of course, less abundant and smaller
than in the later stages. The nucleus develops also and the
chromatin is well differentiated. Thus the development in both
the cell body and the nucleus proceeds rapidly in the earlier
stage.




Line 18,309: Line 21,706:




20 Days






13








366 Days






Fig. 13 Showing semi-diagrammatically the size and the morphological
changes in the ganglion cells in the ganglion spirale of the albino rat at the age of
1, 20 and 366 days. All cell figures have been uniformly magnified 1000 diameters.






GROWTH OF THE INNER EAR OF ALBINO RAT






131






At twenty days the cell body reaches its maximum size. The
Nissl bodies are large and abundant. The nucleus also attains


TABLE 99


Comparison according to side of the cell bodies and their nuclei in the ganglion


spirale






AGE




Line 18,340: Line 21,751:




SIDE




COMPUTED I.I \ M K r Ml- ft




Line 18,348: Line 21,761:




Cell




12O
Nucleus




days




grams




Line 18,365: Line 21,781:




1




5




2




R.




10.6




8.0




Line 18,383: Line 21,805:




L.




10.4




7.8




3




7




1




R.




11.4




8.0




Line 18,407: Line 21,838:




L.




11.5




8.0




6




11




2




R.




13.0




8.5




Line 18,431: Line 21,871:




L.




12.9




8.4




9




9




2




R.




13.4




8.5




Line 18,455: Line 21,904:




L.




13.7




8.6




12




12




1




R.




13.9




8.4




Line 18,479: Line 21,937:




L.




14.0




8.4




15




13




1




R.




,*
14.7




8.6




Line 18,504: Line 21,970:




L.




14.8




8.5




20




29




2




R.




18.0




10 1




Line 18,528: Line 22,003:




L.




18.5




10.2




25




36




2




R.




17.6




10.1




Line 18,552: Line 22,036:




L.




17.7




\t\f\
10 1




50




59




2




y
R.




17.5




9.9




Line 18,578: Line 22,069:




L.




17.5




9.8




100




~
102




~
2




R.




16.8




9.5








123








L.




17.0




9.5




150




189




1




R.




16.4




9.2




Line 18,628: Line 22,136:




1UO
L.




16.5




1  
9.1  




257




137




2




R.




17.1




9.7




Line 18,654: Line 22,169:




L.




16.6




9.5




367




175




2




R.




17.3




9.7




365




188








L.




16.5




9.1




546




255




2




R.




16.9




9.3




Line 18,702: Line 22,237:




L.




16.9




9.9




Average right side
Average left side
Right larger than left
Left larger than right
Right and left equal




15.3
ir>.:j
4
8
2




9.1
'.M)
7
2
5






its maximum size at this age, though the rate of increase is slower
than that for the cell body. With this increase of size the his-
tological structure becomes that of the adult rat. Then, as the






132






ANATOMICAL AND PHYSIOLOGICAL STUDIES ON






age advances, the size of both the cell body and of the nucleus
slowly diminishes, while within the cytoplasm the differentiation
of the Nissl bodies progresses. This relation is seen in the figure
of the cell at 366 days, which shows that the absolute volume
of the cell body and also of the nucleus is smaller than at twenty
days.


From twenty to 366 days, gradual and progressive changes
in all histological structures can be seen, though there are no
sudden changes.






TABLE 100






Diameters of the cell bodies and their nuclei in the ganglion spirale in cross sections


of the cochlea (chart 4%)




Line 18,739: Line 22,309:




DIAMETERS IN M




AGE




BODY




Cell body




Nucleus




Line 18,753: Line 22,328:




Long




Short




Computed




Long




Short




Computed




days




grams




Line 18,781: Line 22,364:




15




20




15.7




14.3




15.0




9.3




8.4




8.8




20




27




18.3




16.6




17.4




10.3




10.0




10.1




25




39




18.0




16.6




17.3




10.1




9.8




9.9




100




95




17.6


Qf\


16.2




16.9 '


1


9.9


o


~j
9.5




^
9.7




150




169




17.4




16.0




16.7




9.8




9.1




(
9.4




371




220




16.5




15.8




16.2




9.5




8.6




9.0


^


Ratios 15 25 days


a






1 1.1




Line 18,895: Line 22,520:




1 1.1




15371 "








1.1




Line 18,907: Line 22,535:




1.0




25371 "


ou






1.0




Line 18,920: Line 22,550:




0.9






The question here arose whether this change in volume was
in any way related to a shift in the long axis of the cell at the
later ages. To answer this difficult question it was deemed
desirable to compare the form of the ganglion cells obtained in
the cross-section with that found in the radial section of the
cochlea. In table 100 (chart 42) are given the values for the
diameters of the cell bodies and their nuclei in the ganglion
spirale in the cross-section. Below are given the respective
ratios from 15 to 25, 15 to 371, and 25 to 371 days. Both cell
body and nucleus increase in size up to twenty days and then
diminish very slowly, as the age advances. These are similar
to the relations found in the radial sections.






GROWTH OF THE INNER EAR OF ALBINO RAT






133






Looking at the diameters of the cell bodies and their nuclei
in each turn (table 101), we do not find in the later age groups a
regular increase in passing from the base toward the apex, as
in the cells on the radial section. The differences are generally


TABLE 101


Diameter of the cell bodies and their nucki in the ganglion spirale according to the
turns of the cochlea (cross section)




Line 18,943: Line 22,595:




TURNS OV THE COCHLEA




AGE




BODT
WEIGHT








I




II




ill




IV




Line 18,965: Line 22,625:




Computed diameters ft




Line 18,971: Line 22,632:




Cell
body




Nucleus




Cell
body




Nucleus




Cell
body




Nucleus




Cell
body




Nucleus




days
15




grams
20




15.0




8.7




14.7




8.8




14.9




8.9




14.9




9




20




27




16.7




9.7




17.2




10.0




17.5




10.1




18.1




10 6




25
100




39
95




16.9
17.2




10.0
10.0




17.2
16.9




9.9
9.6




17.6
16.7




9.8
9.6




17.3
16.8




10.0
9 6




150




169




17.0




9.9




16.6




9.3




16.6




9.4




16.4




9 1




371
Ratio 15-




220
371 days




16.2
1:1.1




9.6
1:1.1




16.2
1:1.1




9.1
1:1.0




16.0
1:1.1




8.7
1:1.0




16.3
1:1.1




9.0
1:1.0






20






15






10








AGE DAYS-






O






25




fj


50


i




Chart 42 The average diameter of the largest cell bodies and of their
nuclei of the nerve cells from the ganglion spirale, after 15 davs (cross-section)
table 100.


Cell bodies. -.-.-.-.-. Nuclei.


g




/A
134 ANATOMICAL AND PHYSIOLOGICAL STUDIES ON


f*f\
far smaller than on the radial section. This result seems to have
some connection with the position of the long axis of the ganglion
cells in relation to the axis of the cochlea.


Comparing the diameters of the cell bodies and their nuclei
in nearly corresponding places in the radial and cross-section,
the long diameters of the cells are in each age group almost
always larger in the radial than on the cross-section. Therefore
the cells are somewhat ovoid. The short diameters, however,
are at the same age sometimes longer, sometimes shorter on the
radial than on the cross-sect on. This is probably due to the
fact that in the upper turns the cells stand with their long diameter
more nearly parallel to the axis of the modiolus, and therefore,
on passing from the upper to the lower turn, the long axes of
the cells become more inclined to the modiolus.


In order to show that the cell form is ovoid, I reconstructed
the cells at 15, 100, and 365 days of age by the usual method,
and obtained models which agreed in form with that determined
by the microscope.


It appears, therefore, that while there is some difference in
the diameters of these cells according to the plane of the section,
neverthless, the change in volume after twenty days is similar
in both cases, and so this change does not depend on the plane in
which the sections were made.


On the nucleus-plasma relations of the cells in the ganglion
spirale. The computed diameters of the cell bodies and their
nuclei, measured on radial sections, are given in table 102 and
the nucleus-plasma ratios have been entered in the last column.
The ratio is at one day only 1:1.3 and increases rapidly and
regularly till twenty days; after that period there are slight fluc-
tuations. Generally speaking, the ratios increase with the ad-
vancing age of the rat, but after twenty days only very slightly.
Thus we see that the nucleus-plasma relation nearly reaches an
equilibrium at twenty days, though the cells mature slowly
even after that time.


When we consider this relation according to the turns of the
cochlea, we find that this ratio increases in all the turns regularly
and definitely till twenty days, after which there are some






GROWTH OF THE INNER EAR OF ALBINO RAT






fluctuations (table 103). Thus we see here also the same relation
as before.






TABLE 102
Nucleus-plasma ratios of cells in the ganglion spirale (radial-vertical section)






AGE




BODY
WEIOHT




BOOT
LENGTH




COMPUTED DIAMETERS M




Cell body




Nucleus




N ucleus-plasma
ratios




days




grams




mm.




Line 19,163: Line 22,970:




1




5




48




10.5




7.9




1 : 1.3




3


|


8


2


56




11.5




8.0




:2.0


Y


6




25
11




63


50


12.9




Chart 18 The radial distance between labium vestibulare and the habenula
8.4
perforata according to the turns of the cochlea, table 41.  


radial breadth from the labium vestibulare to the inner edge
of the head of the inner pillar cell, I have used, at earlier stages,
as in the preceding chapter, the same small prominence as an
inner fixed point (fig. 4). In table 44 (chart 19) are given the
values for this radial distance according to age. At the bottom
of the last column are given the ratios from 1 to 9, 1 to 546


:2.6




72
9




10


ANATOMICAL AND PHYSIOLOGICAL STUDIES ON


58




TABLE 43
13.6


Distance between labium vestibulare and habenula perforata in n (Bottcher)


8.5




PLACE OF
:3.1




CAT EMBRYO 9 CM.
12




CAT EMBRYO 11 .5
13




CAT THREE DAYS
60




ADULT CAT
13.8




MEASUREMENT
8.5




LONG
:3.3




CM. LONG
15




OLD
13




75




I turn
14.9




120
8.7




120
:4.0




120
20




100
29




II turn
95




130
18.1




130
10.2




130
:4.6




110
25




III turn
36




150
104




140
17.7




140
10.1




130
:4.4




50


TABLE 44


59




Radial distance between the labium veslibulare and the inner edge of the head of the
125
inner pillar cell on age (chart 19)




17.5


AGE


10.0


BODY WEIGHT


:4.4


TURNS OF THE COCHLEA M


100


I


112


II


159


ill


16.9


IV


9.5


Average


:4.6


days


150


grams


183




190




16.7




9.2




:5.0




257


1


137


5


175


111


16.8


126


9.6


138


:4.4


130


366


126


181


3


191


8


16.9


84


9.4


118


:4.8


150


546


170


255


131


213


6


16.9


11


9.4


88


:4.8


119




159
TABLE 103


Nucleus-plasma ratios of cells in the ganglion spirale according to the turns of the
cochlea. Based on table 96


180




136
AQB




9
BODY WEIOHT




10
TURNS Or THE COCHLEA




94
I




131
ii




168
in




179
IV




143
days




12
grama




13




69




97




138




156
1




115
5




15
1 :1.6




13!
1 :1.5




",' 66
1 :1.2




103
1 : 1.2




137
3




149
8




114
:2.1




20
:2.1




29
:2.1




66
:1.7




103
6




137
11




148
:2.6




114
:2.6




25
:2.6




36
:2.7




65
9




100
10




136
:3.1




148
:2.9




112
:3.0




50
:3.0




59
12




61
13




98
:3.7




129
:3.6




144
:3.1




108
:3.4




100
15




112
13




64
:4.1




99
:4.3




139
:3.9




153
:3.2




114
20




150
29




183
:4.5




60
:4.6




99
:4.6




129
:5.1




143
25




108
36




257
:4.0




137
:4.5




67
:4.3




100
:4.7




134
50




149
59




113
:4.6




366
:4.6




181
:4.5




60
:4.6




102
100




130
112




151
:4.5




111
:4.8




546
:4.4




255
:4.5




55 :..
150




99
183




128
:5.0




143
:4.9




106
:5.1




:5.5


Ratios 1 9 days


1546 "
257
12546 "




137


1.1


0.8
:4.3
0.9




:4.6


TABLE 45 Condensed


:4.3




Ratios of the radial distance between the habenula perforata and the inner edge of
:4.4


the head of the inner pillar cell according to the turns of


the cochlea on age
366




181




:4.8




:4.7


KATIOS BETWEEN TURNS


:5.2


AVERAGE AGE


:5.1


WEIGHT


546




255




:5.1




:4.2




:4.8




:5.1


I-II




I-HI
136




I-IV


ANATOMICAL AND PHYSIOLOGICAL STUDIES ON


days




grams
In the nucleus-plasma ratio of the cells on the cross-section,
as shown in table 104, the increase with age is very regular.
As the diameters of the cell bodies and their nuclei decrease
slowly after twenty days, this increase of the ratio means that
the nuclei are diminishing relatively more rapidly than the
cytoplasm.


Comparing these ratios from the radial and cross sections,
we find that they agree (table 105) .


TABLE 104


Nucleus-plasma ratios of the cells in the ganglion spirale (cross-sections)




Line 19,715: Line 23,544:




1




5




1 1.1
COMPUTED DIAMETERS M




1 \.9




1 1.2




6
BODY LENGTH




10




1.4
AGE




1.8
BODY WEIGHT




2.0




154




102




1.5




2.1




2.3






GROWTH OF THE INNER EAR OF ALBINO RAT




Cell body


73


Nucleus




and 12 to 546 days of age. As the table shows, the values increase in general from birth to nine days; therefore, the surface
Nucleus-plasma
of the greater epithelial thickening from the labium vestibulare
ratios
to its outer boundary becomes, during the earlier stage, wider
and wider, then decreases sharply, and after that continuously
but slowly. This sudden diminishing of the distance has a very
intimate relation with the change in the form of the papilla
spiralis at this stage of development.


This point I will discuss later.


That the values increase from the base to the apex first rapidly
days
and later less rapidly, is also to be seen here. Table 45 shows this
relation clearly. It is remarkable, however, that the ratio becomes




grams


140


mm.




12O






1OO






AGE DAYS'
15




20


25


84




50 50 1OO 2OO 300 400 50O
15.0


Chart 19 The radial distance between the labium vestibulare and the
inner edge of the head of the inner pillar cell, table 44.


at each turn larger with age, although the absolute value is
8.8
after nine days generally smaller than at the preceding age.
Therefore, we see that the diminution of the distance after
nine days is largest in the basal turn and smallest in the apical.
Hensen ('63) asserts that there is a movement axialward of
the organ of Corti (resp. the head of the pillar cell), but gives no
measurements. Neither Bottcher nor Retzius measured this
distance. Prentiss ('13, page 445) states that "the distance
between the inner angle of the cochlea and the pillar cells, two
definite points, may be measured with considerable accuracy
and shows no important change in the position of the spiral
organ from the 13 cm. to the 18.5 cm. stage, nor later in the
new born animal" (pig) But he also does not record his measurements.  




1 4.0


74


20




ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
27




93


Hardesty ('15, p. 54) says "that the space occupied by the
width of the greater epithelial ridge increases throughout the
coils of the cochlea up to pigs of 15 to 16 cm., and thereafter
it begins to decrease very perceptibly." He measured the
width ''from the membrana propria of the epithelium of the
greater ridge, at its most axial extension under Huschke's teeth,
to the apical end of the inner hair cell of the spiral organ. " The


TABLE 46
17.4


Vertical distance from the membrana basilaris to the surface of the pillar cells on


age (chart 20}
10.1




4.1




25




39


TURNS OF THE COCHLEA M


114


AGE


17.3


BODY WEIGHT


9.9




4.3




100




95


I


152


II


16.9


ill


9.7


IV


4.5


Average


150


days


169


grams


192




16.7




9.4




4.6




371




220


1


206


5


16.2


35


9.0


36


4.8


39




36
TABLE 105


The nucleus-plasma ratios according to the plane of the section at two age periods


37
albino rat




3


AGE


8


NUCLEUS-PLASMA RATIO
ON THE RADIAL SECTION


30


NUCLEUS-PLASMA RATIO
ON THE CROSS SECTION


29


AGE


29


days
15


29


1 :4.0


29


1 :4.0


6


days
15


11


366


29


1 :4.8


32


1 :4.8


31


371


29
==Discussion==


According to the foregoing data, the maximum
size of the cells in the ganglion spirale, at twenty days, is in
cross-sections about 18.7 x 16.9 y. for the cell body and 10.3 x
10.0 [L for the nucleus. Both the long and short diameter of
the cell body thus obtained is therefore a little less than that
obtained in the radial section, while the diameters for the nu-
cleus are the same.


30
In the literature we have not found any data for the Norway
rat, but there are a few observations on the size of these cells
in other mammals by Kolliker ('67) and von Ebner ('02).




9
Schwalbe ('87) and Alagna ('09) find these ganglion cells 25
to 30 JJL in diameter in the guniea-pig and cat.


Alexander ('99) has also reported measurements on a series
of mammals, but as the size of such cells is greatly influenced
by the method of preparation, and as our averages are based
on the largest cells while those of other authors have been ob-
tained in a different manner, it seems best not to report the other
values in the literature, as they are sure to be misleading.


10
TABLE 106


Showing the changes with age in the diameters of the cells and the nticlei of the
sjriral ganglion afnd the lamina pyrmidalis of the cerebral
cortex, respectively


32




33
AGE '




35
CELL BODY IN
THE OANQL.
SPIRALS COMPUT-
ED DIAM. M




36
CELL BODY IN
THE LAMINA
PYRAMID COM-
PUTED DIAM.




34
NUCLEUS IN
GANOL. SI-IK.
COMP. DIAM.




12
NUCLEUS IN
THE LAMINA
PYRAM. COMP.
DIAM.




13
AGE




41
days




45




50




52




47




15
days




13
1




44
10.5




48
11.4




53
7.9




57
9.4




51
1




Line 20,029: Line 23,859:




29
18.1




53
18.7




57
10.2




67
15.7




71
20




62
546




25
16.9




36
17.0




55
9.4




56
13.8




66
730




68
Ratio be-




61




50




59




53




55
ratio




67
tween 1 and




68
1 : 1.7




61
1 :1.6




100
1 :1.3




112
1 :1.3




53
of Ito




54
20 days




64




67




60




150




183
20




52




54




63




66




59




257
days




137
Ratio be-




53




56




63




69




60
ratio




366
tween 1 and




181
1 : 1.6




51
1 : 1.5




56
1 :1.2




66
1 :1.2




67
of Ito




60
546 days




546




255




52




55




62
730




66




59




Ratios 1 12 days 1-1.3




1 20 " 1.7




1546 " 1.6




12546 " 13
days




20546 " 1.0


Considering the course of growth in these cells, we find it to
be similar in both the spiral ganglion and the lamina pyramidalis
of the cerebral cortex (rat) as reported by Sugita ('18). In the
former the cells attain at twenty days of age, the time of wean-
ing, their maximum size, and then diminish slowly with advancing
age. The cells of the lamina pyramidalis also reach their full
size at twenty days, and then diminish in the same way. There-
fore, the course of the growth of both of these groups of nerve
cells coincides. However, I do not know of other instances
of the phenomenon. When tabulated, the relations here noted
appear as in table 106.


The difference between them is only in the absolute values
of the diameters of the cell bodies and especially of the nuclei,


method of measurement differs from mine, so the results cannot
be compared directly. While the distance in the rat increases
to nine days of age, that in the pig decreases perceptibly in
fetuses more than 16 cm. long.


According to Hardesty ('15, p. 55). "the decrease in the I
and III half turns may be as much as one-third of the width
of the greater ridge when at its maximum size and activity. "
And "after the tectorial membrane is about completely produced,


138


the nuclei in the cells of the lamina pyramidalis being decidedly
larger than in those of the spiral ganglion. The ratios of in-
crease are, however, similar.


GROWTH OF THE INNER EAR OF ALBINO RAT
When we consider the increasing ratios of the diameters of
the ganglion cells, we see a close similarity in the maximum values
between the cells in the spiral and gasserian ganglion (Nittono,
'20). Nevertheless while in the former the ratios from 1 to 20
and 1 to 366 days are in the cell bodies 1:1.7 and 1 : 1.6, respec-
tively, in the latter the ratios for the corresponding intervals are
1: 1.43 and 1: 1.69, respectively (Nittono, '20, p. 235). In the
nucleus also similar relations are to be seen in both ganglia.


As these ratios show, there is in the gasserian ganglion a definite
increase in the diameters of cells and nuclei after 20 days of age;
the time when the maximum is reached by the cells of the spiral
ganglion. Thus the former continue to grow after growth in
the latter has ceased. These results suggest that the neurons in
the more specialized ganglia, like the spiral ganglion, may mature
earlier than do those in the less specialized.


On the correlation between the growth of the hair cells of the papilla
spiralis and of the nerve cells of the ganglion spirale. When we
compare the growth changes in the hair cells with those in the
ganglion cells, we find that the course of the development is
similar. Both classes increase in volume from one to twenty
days of age, then tend to diminish slowly the hair cells more
slowly than the ganglion cells. In the ratios of increase, however,
there are marked differences. Thus in table 67 (bottom of last
column) the volume ratios from 1 to 20 and 20 to 546 days are
1 : 2.4 and 1 : 0.9, respectively in the hair cells, and in the ganglion
cells, table 108, the ratios of the volumes in the fourth column
work out for the corresponding ages as 1: 5.1 and 1: 0.8, re-
spectively. In the case of the nuclei the growth changes are
somewhat different. In the hair cells the nucleus grows in
diameter more rapidly, and therefore reaches at nine days its
maximum value and then diminishes at succeeding ages.


75
I have sought to determine whether there was any correlation
in growth between either the entire cylindrical surface or the area
of the cross-section of the hair cells, on the one hand and the volume






and while the spiral organ is enlarging, the inner hair cells, and
139
therefore the organ, may be moved in the apical coil of the
cochlea axialward a distance of about half the maximum width


of the greater epithelial ridge, "


The differences of the values in the rat at 9 and 546 days are
in the basal and apical turn about the same, 39 and 36 n, respectively (table 44). Thus while the inner edge of the inner
pillar cell approaches at 546 days in the basal turn by as much
as 41 per cent of the distance present at nine days, that in the


of the cells of the ganglion spirale on the other. The reason for
making this comparison was the fact that Levi ('08), Busacca
('16), and Donaldson and Nagasaka ('18) have noted in the cells
of the spinal ganglia of several mammals that the postnatal
growth in volume was correlated with the increase in the area of
the body surface, and recently Nittono ('20) has found in the
rat a similar relation between the growth of the cells of thegasserian
ganglion and the area of the skin of the head. On examining
this problem, it is evident that the correlations thus far reported


TABLE 107


80
Comparison of ratios between the volumes of the cells of the ganglion spirale. nn<l ///


ratios of the area of the cylijidrical surface of the hair


cells of the organ of Corti on the maximum values


60




AOE


40


BOOT
WEIGHT




20
VOLUME OP 1 III
ClANllI.ION CELL,
/'




RATIOS ON
THE
MAXIMUM
VALUE


AGE.qAYS


AKEA OF
CYLINDRICAL
SURFACE OF THE
HAIR CF.LLH- M *


25 50 5Q 1QO 2OO 300 4OO 5OO


Chart 20 The vertical distance from the membrana basilaris to the surface
1ATIO8 ON THE
of the pillar cells, table 46, figure 1, 1-1.
MAXIMUM
VALUE


apex moves only 20 per cent inward in old age. This result
is the reverse of that obtained in the pig by Hardesty. The
reason for this contradiction I will discuss later.


10. The vertical distance from the membrane basilaris to the
days  
summit of the pillar cells. The method of getting the vertical
distance from the membrana basilaris to the surface of the
pillar cells is shown in figure 1, line 1-1. In table 46 (chart 20)
are given the values thus obtained. At the foot of the last
column are given the ratios of this distance at 1 to 12, 1 to 20,
1 to 546, 12 to 546, and 20 to 546 days. The average value is
relatively large at birth, it diminishes at three days, then increases
more rapidly to twenty days. After this it decreases very slowly.
The maximum height of the arch of Corti is at twenty days of




gms.


76






ANATOMICAL AND PHYSIOLOGICAL STUDIES ON




I


age. Comparing the values for the height in each turn, we find
that from nine days they increase from the basal to the apical
turn. This relation can be easily seen in table 47.


Retzius ( '84) gives in the rabbit and cat the following values
5
(table 48).




606


TABLE 47 Condensed


3105




Ratios of the vertical distance from the membrana basilaris to the surface of the
1 :5.12
pillar cells according to the turns of the cochlea




395




723




1


RATIOS BETWEEN TURNS


1.83




3


AVERAGE BODY


8




796


AVERAGE AGE




WEIGHT






:3.90




463




Line 20,340: Line 24,188:




I-II


1.56


i-ni


6


I-IV


11


days


1124


grams




Line 20,358: Line 24,205:




:2.76




582


1




5




1 :1.0




1 : 1.1


1.24


1 : 1.0


9


1


10


11


1317


: 1.1




: 1.1




: 1.1


:2.36


18


648


21




: 1.1




: 1.2




: 1.3


1.12


213


12


138


13


: 1.0


1376


: 1.2




: 1.3






TABLE 48
:2.26
Vertical distance from the membrana basilaris to the summit of the pillar cells




681


BABBIT




CAT




Age




Basal


turn
1.03




Middle
15
turn




Apical
13
turn




Average
1732




Basal
turn




Middle
turn




Apical
:1.79
turn




Average
729




days




Line 20,474: Line 24,301:




0.99




20




29




3105




Line 20,486: Line 24,317:




New-born
: 1.00




45
723




70




61




59




45
1.00




60
25




48
36




51
2903




2




45




69
: 1.07




40
691




51




Line 20,532: Line 24,357:




1.05




50




59




2806




3








:1.11




697




Line 20,555: Line 24,385:




39
1.04




60
100




112




2527








7




46
: 1.23




60
678




60




55




45




47
1.07




50
150




44
183




10
2439




45




69




69
:1.28




61
691




Line 20,615: Line 24,441:




1.05




257




137




11
2483
 




Line 20,627: Line 24,457:




: 1.25




689








JK




50




60
1.05




42
366




51
181




14
2527




45




57




66
: 1.23




56
683




Line 20,669: Line 24,497:




1.06




546




255




30
2527




Line 20,682: Line 24,513:




: 1.23




699






' }'




33




51


1.03


57




47
apply to the postnatal growth period, and that we must consider
that the functional relations of the skin are well established,
even at the earliest age. The data with which we have worked in
the case of the cochlea are presented in several tables (107 to
110).


In tables 107 and 108 are given the volumes of the cells of the
ganglion spirale and the areas of the cylindrical surface of the
hair cells. In table 107 the ratios are computed by dividing the
maximum value by the values at each age, and in table 108 by
dividing the values at each age by the initial value.




Table 48 shows that the height of the arch of Corti in the
rabbit approximates that in the rat, though there are considerable
differences in the earlier stages. In the former the arch of Corti
develops after: birth only a little, and is therefore more precocious than in the rat. In the cat the same relation is to be
seen, but the absolute values in the latter animal are smaller
than in either the rabbit or the rat.


TABLE 108


Comparison of the ratios of the volume of the cells of the ganglion spirals with the


GROWTH OF THE INNER EAR OF ALBINO RAT 77
ratios of the area of the cylindrical surface of the hair cells of the organ of


11. The greatest height of the tunnel of Corti. Some authors
Corti on the initial values  
have reported in several animals the appearance of the tunnel
of Corti just after birth, or even in later intrauterine life. In
the rat, however, it first appears through all the turns after
the ninth day. Sometimes we see it at nine days in the lower
turn, though not yet in the upper. The method of measuring
the height is shown in figure 1, line 1-1'. Table 49 (charts 21
and 22) gives the values for the greatest height of the tunnel of
Corti. At the foot of the last column are given the ratios from
12 to 25, 12 to 546, and 25 to 546 days.


As the table shows, the space appears in all the turns at twelve
days and has considerable height. This increases to twenty-five
days, than decreases very slowly. This increase and decrease
correspond to the changes in the distance of the summit of the
pillar cells from the basilar membrane.


When we consider the height in each coil of the cochlea, we
find the value increases from the base to the apex, first rapidly
then slowly. In table 50 this relation is clearly shown.


Retzius ('84) gives the values for the adult rabbit, man and
AGE
cat (one month) as follows (table 51).


According to this table, the average height is in the adult
man, cat, and rabbit somewhat less than in the rat.


12. The height of the papilla spiralis at the third series of
BOOT
the outer hair cells. The measurements were taken along the
WEIGHT
line 2-2 shown in figure 1. The growth of this vertical height
depends not only upon the increase of the length of the corresponding outer hair cell, but chiefly upon the development of
the Deiters' cells, especially of the outermost row, and of the
sustentacular cells of Hensen.


In table 52 (charts 23 and 24) are given the values for this
vertical height of the papilla spiralis at the third series of the
outer hair cells according to age. At the bottom of the last
column are the ratios at 1 to 12, 1 to 20, 1 to 546, and 20 to 546
days. The heights decrease at three days, but increase from
nine to twelve days very rapidly, nearly doubling their minimal
values, and reach a maximum at twenty days. After that time
they decrease very gradually to the end of the record. There


VOLUME OF THE
GANGLION


78
CELLS M *




RATIOS ON THE
INITIAL
VALUE


ANATOMICAL AND PHYSIOLOGICAL STUDIES ON


AREA OF THE
CYLINDRICAL
SURFACE OF THI
HAIR CELLS M




TABLE 49
RATIOS ON
Greatest height of the tunnel of Corti on age (charts 21 and 22}
, THE INITIAL
\ VALUE




days


AGE


grams


BODY WEIGHT




TURNS OP THE COCHLEA M




I


1


II


5


ill


606 : 606


IV




Average


 
1
days




grams
1.00




395




395








1




1.00




1
3




5
8




: 796




Line 20,823: Line 24,636:




1.31








463




Line 20,832: Line 24,647:




3


1.17


8


6




11




: 1124




Line 20,847: Line 24,664:




1.85








582




6




11




1.47




9




10




: 1317




Line 20,871: Line 24,692:




2.17






9 1


 
648
10




Line 20,884: Line 24,704:




1.64




12




13




: 1376




Line 20,895: Line 24,719:




12


2.27


13




29


681


33




39




37


 
1.72
35




Line 20,922: Line 24,741:




31
: 1732




34




42




46
2.86




38




20
729




29




37




42
1.85




52
20




56
29




47
:3105




25




36




39
5.12




41




54
723




56




48




50
1.83




59
25




38
36




41
:2903




53




57




47
4.79




100




112
691




38




43




51
1.75




56
50




47
59




150
:2806




183




37




41
4.63




49




54
697




45


257




137


1.76


38


100


43


112


51


:2527


56




47




366


4.17


181




37


678


41




52




53


1.72


46


150


546


183


255


:2439


36




39




48


4.02


53




44


691




Ratios 12 25 days
12546 "
25546 "






1.4
1.3
0.9


1.75




1 In one case nine days old which could hear the space was found
257
through all the turns of the cochlea.


TABLE 50 Condensed


Ratios of the greatest height of the tunnel of Corti according to the turns of the
137


cochlea on age


:2483




Line 21,132: Line 24,916:




, RATIOS BETWEEN TURNS
4.10








AVERAGE BOOT
689








AVERAGE AGE




WEIGHT
1.74




366




181




:2527




Line 21,158: Line 24,944:




I-II
4.17




i-ni




I-IV
683




days




grams




1.73




546




255




12
:2527




13




1 : 1.1




1 1.3
4.17




1 1.3




18
699




21




:1.1




1.4
1.77




1.5


TABLE 109


213
Area of the cross-section of the inner and outer hair cells




138




:1.1




1.3




1.4






TABLE 51
WEIGHTED
The greatest height of the tunnel of Corti in n (Retzius)






RABBIT




CAT (one month)




MAN


DIAMETER OF


Basal


AVERAGE


Middle


DIAMETER OF


Apical


WEIGHTED


Average


AGE


Basal


BODY


Middle


ONE INNER


Apical


DIAMETER OF


Average


INNER AND


Basal


AREAS OF CROSS


Middle




Apical


WEIGHT


Average


HAIR CELL


30


THREE OUTER


39


OUTER HAIR


36


SECTION OF


35




18




37


M


36


HAIR CELLS


30


CELLS


28


HAIR CELLS


45




49




41






GROWTH OF THE INNER EAR OF ZLBINO RAT
M




M


79


M 2




fore, the difference between the ratios at 1 to 20 and 1 to 546
days  
days is very small.


At twelve days and after, the values for the height increase in
passing from the base to the apex, at first rapidly, then more
slowly. In the earlier stages this relation is obscure or reversed.


grams




60
40


20
n




Line 21,341: Line 25,103:




1




5




6.6




6.0




6.2




30




3




8




8.0




7.4




7.6




45




6




11




8.1




7.6




7.7




48




9




10




8.8




8.5




8.6




5S




12




13




8.5




8.3




8.4




55




15




13




8.4




7.7




7.9




50




20




29




8.8




8.2




8.4




55




25




36




8.8




8.1




8.3




55




50




59




8.8




8.2




8.4




55




100




112




8.6




8.1




8.2




53




150




183




8.5




8.3




8.4




55




257




137




8.5




8.3




8.4




55




366




181




8.8




8.4




8.5




58




546




255




8.6




8.2 | 8.3




55






GROWTH OF THE INNER EAR OF ALBINO RAT






141






I have calculated the cylindrical surface of the hair cells
according to the formula for the lateral surface of a cylinder;
therefore, this area equals 2 v r a (r = radius, a = height of the
cylinder) . As the hair cells are more or less pointed at their lower
end, the surface obtained by this formula has nearly the value of
the total surface of the hair cells less that for the upper end disk.


As has been already shown, both classes of cells grow rapidly
from birth to twenty days, and after that both tend to decrease
slightly in volume. It is evident that during the growing period,


TABLE 110


Comparison of the ratios of the volume of the cells of the ganglion spirale with the


ratios of the areas of the cross-section of the inner and outer hair cells


of the organ of Corti






AOE


days




BODY
WEIGHT


gms




VOLUME OF THE
GANGLION
CELLS M '




RATIOS ON THE
INITIAL
VALUE




AREA Or THE
CROSS-SECTION
OF THE HAIR
CELLS




RATIOS ON THE
INITIAL
VALUE




1




5




606




606




1




1.00




30 :30




1




1.00




3




8








796








1.31




:45








1.50




6




11








1124








1.85




:48








1.60




9




10








1317








2.17




:58








1 . 9




1
12




^
13








1376








2.27




:55








1.83




15




13




JS.




1732








2.86




:50








1.67




20




29








3105








5.12




:55








1.83




25




36








2903








4.79




:55


/






l s:;




50




59








2806








4.63




:53








1.77




100




112








2527








4.17




:53








1.77




150




183








2439


x






4.02




:55








1.83




257




137








2483








4.10




:55








1.83




366




181








2527








4.17




:58








1.93




546




255








2527








4.17




:55








1.83






from one day to the end of the record, the volumes of the ganglion
cells increase more rapidly than do the cylindrical areas of the
hair cells (table 108). If we seek a numerical expression of these
relations, it seems best to start not with the values at birth, but
with those at nine days of age when the cochlea is just beginning
to function, and to extend the comparison only up to twenty days
when both groups of cells have reached their maximum size.
Thus at nine days (table 108) the volume of the ganglion cells
is 1317 [A 3 , while at twenty days it is 3105 [A 3 , or as 1: 2.3, while
the area of the cylindrical surfaces of the hair cells at the respective






142 ANATOMICAL AND PHYSIOLOGICAL STUDIES ON


ages is 648 [x 3 and 723 [i 3 , or as 1 : 1.1, thus showing a rapid growth
of the ganglion cell bodies accompanied by but slight enlargement
of the hair cells.


It is evident from these ratios that the ganglion cells are
increasing in volume more rapidly than the hair cells in area.
It is possible that the nervus cochlearis innervates the other
cells of the cochlea as well, but even if this is taken into con-
sideration the general relations remain the same.


It follows from this that during the period between the earliest
appearance of the functional response (nine days) and the
attainment of the maximum size of the cells, the innervation
of the hair cells is steadily improving, if we may infer such an
improvement from the increase in the volume of the ganglion
cells. After the close of this early growing period the relations
are approximately fixed through the remainder of life. We do
not find, therefore, in the cochlea any relation which corres-
ponds to those found between the spinal ganglion cells or those
of the gasserian ganglion and the associated areas of the skin
during postnatal growth. This seems to indicate that in the
cochlea growth is fixed or limited, while in the body as a whole
it is more or less continuous, and the ganglion cells behave
differently in the two cases.


In table 109 are shown the diameters of the inner and outer
hair cells and their weighted diameters. In the last column
is given the area of the cross-section of the hair cells.


The ratios of these areas on the initial area are shown in table
110 in comparison with the volumes of the ganglion cells on the
initial volume, and indicate that from three days of age the
values for the ganglion cells are increasing more rapidly than
those for the area of the cross-section of the hair cells, and at
twenty days the increase in the case of both elements has reached
a maximum. Here, as in the case of the cylindrical surface,
both elements show like phases of growth, but the increase in
the volumes of the ganglion cells is much greater than the increase
in the cylindrical area or cross-section of the hair cells.


As it may be desirable to use for comparison the measure-
ments on the cells of the ganglion spirale as here reported, the






GROWTH OF THE INNER EAR OF ALBINO RAT






143






constants for the determinations based on 160 cells in each age
group are given in . table 111 for the radial vertical sections
and in table 112 for the cross-sections.


TABLE 111


A nalytical constants* giving the mean, standard deviation and coefficient of variability
unth their respective probable errors for the diameters of the cells and their
nuclei of the ganglion spirale in radial vertical section






AOK


days




FOR TOTAL NUMBER "K CELLS




Cell
Nucleus




Mean




Standard
deviation




Coefficient of
variability




1




Cell




10.2 0.05




0.90 0.03




8.9 0.33








Nucleus




7.8 0.02




0.46 0.01




5.9 0.22




3




Cell




11.3 0.03




0.50 0.02




4.4 0.17








Nucleus




7.9 0.02




0.32 0.01




4.1 0.15




6




Cell




12.6 0.04




0.68 0.03




5.4 0.20








Nucleus




8.4 0.03




0.48 0.02




5.7 0.22




9




Cell




13.1 0.03




0.61 0.02




4.7 0.18








Nucleus




8.5 0.03




0.52 0.02




6.1 0.23




12




Cell




13.4 0.05




0.86 0.03




6.4 0.24








Nucleus




8.4 0.03




0.61 0.02




7.3 0.28




15




Cell




14.6 0.04




0.73 0.03




5.0 0.13








Nucleus




8.7 0.03




0.58 0.02




6.7 0.25




20




Cell




17.8 0.06




1.17 0.04




6.6 0.25








Nucleus




10.0 0.02




0.40 0.02




4.1 0.15




25




Cell




17.3 0.05




0.88 0.03




5.1 0.19








Nucleus




9.9 0.02




0.36 0.01




3.6 0.14




50




Cell




17.2 0.04




0.78 0.03




4.5 0.17








Nucleus




9.7 0.02




0.34 0.01




3.6 0.14




100




Cell




16.5 0.03




0.65 0.02




3.9 0.15








Nucleus




9.4 0.02




0.38 0.01




4.0 0.15




150




Cell




16.4 0.03




0.79 0.02




4.8 0.18








Nucleus




9.1 0.02




0.42 0.02




4.6 0.17




257




Cell




16.6 0.06




1.09 0.04




6.6 0.25








Nucleus




9.5 . 02




0.39 0.01




4.1 0.15




366




Cell




16.7 0.05




1.02 0.01




6.1 0.22








Nucleus




9.3 0.03




0.52 0.02




5.6 0.21




546




Cell




16.7 0.06




1 . 06 . 04




6.4 24








Nucleus




9.3 0.02




0.45 0.02




4.9 is






==Conclusion==


For the study of the growth of the nerve cells
in the ganglion spirale fourteen age groups were taken and the
data obtained from the 160 largest cells in each age group.
Besides these, six age groups, representing six cochleas, were
examined in cross-sections to determine the form of the ganglion
cells and the relation of their long axes to the axis of the cochlea.
Here also the ten largest cells in each of four, nearly corre-
sponding turns, were measured. We obtained the following
results :


1 . As thus prepared, the ganglion cells at birth have a maximum
size of 11 x 10 [i in cell body and 8.2 x 7.6 [x in nucleus. At
twenty days the diameters are the largest, 18.7 x 16.9 [x in cell
body and 10.3 x 10.0 [x in nucleus.


TABLE 112


Analytical constants giving the mean, standard deviation and coefficient of vari-
ability with their respective probable errors for the diameters of the cells
and their nuclei of the ganglion spirale, in cross-section






AGE




CeU
Nucleus




FOB TOTAL NUMBER OP CELLS




Mean




Standard
deviation




Coefficient of
variability




days
15




Cell




14.7 0.04




0.40 0.03




2.7 0.21








Nucleus




8.9 0.04




0.34 0.03




3.8 0.29




20




Cell




17.1 0.09




0.83 0.06




4.9 0.37








Nucleus




10.0 0.06




0.58 0.04




5.8 0.44




25




Cell




G
17.1 0.07




E
0.63 0.05




c
3.7 0.28




A




Y5
Nucleus




9.8 0.03




0.30 0.02




3.1 0.23




100




Cell




16.7 0.05




0.44 0.03




2.6 0.20








Nucleus




9.6 0.04




0.36 0.03




3.7 0.25




150




Cell




16.4 0.07




0.69 0.05




4.2 0.32








Nucleus




9 . 4 . 05




. 46 . 03




4.9 0.37




371




Cell




16.0 0.06




0.55 0.04




3.5 0.24








Nucleus




25
9.1 0.05  
 
 
 
50
 
 
 
5O 10O 20O 300 400 5OO
 
 
 
Chart 21 The greatest height of the tunnel of Corti, table 49, figure 1, 1-1
 
 
 
60
 
 
 
40
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
/(
 
 
^'
 
 
 
 
 
 
 
 
 
 
'
 
 
 
 
 
 
 
 
__ (
 
 
 
 
 
 
 
 
 
 
 
 
 
 
_
 
 
 
 
,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
*
 
 
 
 
 
 
 
 
>
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
'
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
L
 
 
 
 
 
 
 
 
^~"
 
 
 
 
 
 
 
 
 
1
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
a
 
 
/
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
n
 
 
 
 
 
 
A
 
 
>/c
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
u
 
 
 
 
 
 
 
 
Y
 
 
 
 
 
 
 
 
 
 
 
2
 
 
5
 
 
 
 
 
 
 
 
5
 
 
 
 
 
5<
 
 
D
 
 
II
 
 
~\c
J\.
 
 
)
 
 
 
 
2(
 
 
)C
 
 
)
 
 
 
 
3(
 
 
DC
 
 
)
 
 
4
 
 
4C
 
 
)0
 
 
 
 
 
 
5C
 
 
)0
 
 
 
 
 
 
 
 
 
Chart 22 The greatest height of the tunnel of Corti, according to the turns
of the cochlea, table 49. .
 
In the condensed table 53 are given the ratios in each turn.
While the ratio of each turn before eight days is about 1:1.1,
and between turns I and II remains constant in the later age,
that for I to III and I to IV is at 18 and 213 days decidedly
larger. Therefore, the increase of the height is most marked
in the III and IV turn, as shown in chart 24.
 
 
 
TABLE 52
 
Height of the papilla spiralis at the third series of outer hair cells on age
(charts 23 and 24)
 
 
 
AGE
 
 
BODY WEIGHT
 
 
TURNS OF THE COCHLEA M
 
 
I
 
 
II
 
 
III
 
 
IV
 
 
Average
 
 
days
 
 
grams
 
 
 
 
 
 
 
 
 
 
 
 
1
 
 
5
 
 
35
 
 
35
 
 
39
 
 
28
 
 
34
 
 
3
 
 
8
 
 
22
 
 
23
 
 
25
 
 
26
 
 
24
 
 
6
 
 
11
 
 
25
 
 
24
 
 
25
 
 
23
 
 
24
 
 
9
 
 
10
 
 
28
 
 
28
 
 
27
 
 
28
 
 
28
 
 
12
 
 
13
 
 
40
 
 
49
 
 
54
 
 
56
 
 
50
 
 
15
 
 
13
 
 
46
 
 
53
 
 
65
 
 
66
 
 
58
 
 
20
 
 
29
 
 
56
 
 
61
 
 
76
 
 
81
 
 
69
 
 
25
 
 
36
 
 
56
 
 
61
 
 
76
 
 
78
 
 
68
 
 
50
 
 
59
 
 
53
 
 
59
 
 
78
 
 
80
 
 
68
 
 
100
 
 
112
 
 
54
 
 
59
 
 
74
 
 
79
 
 
67
 
 
150
 
 
183
 
 
55
 
 
57
 
 
75
 
 
77
 
 
66
 
 
257
 
 
137
 
 
54
 
 
59
 
 
74
 
 
81
 
 
67
 
 
366
 
 
181
 
 
5?
 
 
58
 
 
75
 
 
78
 
 
66
 
 
546
 
 
255
 
 
52
 
 
58
 
 
72
 
 
75
 
 
64
 
 
 
Ratios 1 12 days 1 1.5
1 20 " 2.0
 
 
1546 " 1.9
 
 
20546 " 0.9
TABLE 53 Condensed
 
 
Ratios of the height of the papilla spiralis at the third series of outer hair cells
according to the turns of the cochlea on age
 
 
AVERAGE AGE
 
 
AVERAGE BODY
WEIGHT
 
 
BATIOS BETWEEN TURNS
 
 
I-II
 
 
i-ni
 
 
I-IV
 
 
days
 
 
grams
 
 
 
 
 
 
 
 
1
 
 
5
 
 
1 :1.0
 
 
1 :1.1
 
 
1 0.8
 
 
8
 
 
11
 
 
:1.1
 
 
: 1.1
 
 
1.1
 
 
18
 
 
21
 
 
: 1.1
 
 
: 1.4
 
 
1.5
 
 
213
 
 
138
 
 
: 1.1
 
 
:1.4
 
 
1.5
 
 
 
TABLE 54
Height of the papilla spiralis at the third scries of outer hair cells in n (Retzius)
 
 
 
BABBIT
 
 
CAT
 
 
AGE
 
 
Basal
turn
 
 
Middle
turn
 
 
Apical
turn
 
 
Average
 
 
Basal
turn
 
 
Middle
turn
 
 
Apical
turn
 
 
Average
 
 
days
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
New-born
 
 
48
 
 
70
 
 
60
 
 
59
 
 
45
 
 
60
 
 
45
 
 
50
 
 
2
 
 
45
 
 
70
 
 
54
 
 
56
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3
 
 
 
 
 
 
 
 
 
 
 
 
 
 
40
 
 
58
 
 
 
 
 
 
 
 
7
 
 
54
 
 
69
 
 
66
 
 
63
 
 
42
 
 
5<
 
 
48
 
 
49
 
 
10
 
 
42
 
 
86
 
 
84
 
 
71
 
 
 
 
 
 
 
 
 
 
 
 
 
 
11
 
 
 
 
 
 
 
 
 
 
 
 
 
 
60
 
 
72
 
 
42
 
 
58
 
 
14
 
 
60
 
 
87
 
 
90
 
 
79
 
 
 
 
 
 
 
 
 
 
 
 
 
 
30
 
 
 
 
 
 
 
 
 
 
 
 
 
 
36
 
 
57
 
 
70
 
 
54
 
 
 
80
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
81
 
 
 
Retzius ('84) finds in the rabbit and cat the [values for this
height given in (table 54).
 
Comparing these average numbers with mine, it appears that
the height in the rabbit is greater, and in the cat smaller than
 
 
 
u
 
70
5O
30
10
 
 
 
k
 
 
 
AGE
 
 
 
o
 
 
 
25 5O 50 |OO 2OO 3OO 40O 5OO
 
 
 
Chart 23 The height of the papilla spiralis at the third series of the outer
hair cells, table 52, figure 1, 2-2.
 
 
 
90
 
 
 
70
 
 
 
50
 
 
 
30
 
 
 
10
 
 
 
 
AGE DA.YS
 
 
O
 
 
 
25
 
 
 
50
 
 
 
5O 1OO 2OO 3OO 4OO 5OO
 
 
 
Chart 24 The height of the papilla spiralis at the third series of the outer
hair cells, according to the turns of the cochlea, table 52.
 
in the rat. In both animals the values increase rapidly at ten
to eleven days of age, as in the albino rat, but the height in these
animals is at the earlier stage almost twice as large as in the rat.
Hardesty ('15) measured the thickness of the organ of Corti in
 
 
 
82
 
 
 
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
 
 
the pig in a somewhat different way, using the vertical line from
the basilar membrane proper through the m'ddle of the outer
hair cell to the surface of the organ, and found the increase in
thickness to take place most rapidly at the stages before full term,
though it seems to continue after birth. I have not made cor
TABLE 55
 
Greatest height of Hensen's supporting cells on age (chart 25)
 
 
 
AGE
 
 
BODY WEIGHT
 
 
TURNS OP THE COCHLEA M
 
 
1
 
 
II
 
 
III
 
 
IV
 
 
Average
 
 
days
 
 
grams
 
 
 
 
 
 
 
 
 
 
 
 
I
 
 
5
 
 
36
 
 
36
 
 
38
 
 
31
 
 
35
 
 
3
 
 
8
 
 
18
 
 
21
 
 
21
 
 
24
 
 
21
 
 
6
 
 
11
 
 
21
 
 
20
 
 
21
 
 
18
 
 
20
 
 
9
 
 
10
 
 
20
 
 
23
 
 
23
 
 
24
 
 
23
 
 
12
 
 
13
 
 
40
 
 
49
 
 
56
 
 
58
 
 
51
 
 
15
 
 
13
 
 
44
 
 
56
 
 
69
 
 
72
 
 
60
 
 
20
 
 
29
 
 
64
 
 
64
 
 
86
 
 
87
 
 
75
 
 
25
 
 
36
 
 
69
 
 
71
 
 
84
 
 
86
 
 
78
 
 
50
 
 
59
 
 
71
 
 
74
 
 
87
 
 
89
 
 
81
 
 
100
 
 
112
 
 
77
 
 
. 78
 
 
87
 
 
89
 
 
83
 
 
150
 
 
183
 
 
76
 
 
77
 
 
<3
 
 
93
 
85
 
257
 
 
137
 
 
81
 
 
83
 
 
89
 
 
89
 
 
86
 
 
366
 
 
181
 
 
82
 
 
83
 
 
89
 
 
91
 
 
86
 
 
546
 
 
255
 
 
79
 
 
79
 
 
92
 
 
93
 
 
86
 
 
 
Ratios 1 6 days
 
1 12
 
1 20
 
1546
 
6 12
 
6 20
 
6546
12 20
12546
20546
 
 
 
0.6
1.5
2.1
2.5
2.6
3.8
4.3
1.5
1.7
1.1
 
 
 
responding studies on the rat. In the latter animal, however,
the rapid increase usually appears at twelve days of age, when
the animal as a rule first responds to auditory stimuli, and thus
we have a correlation between the development of the organ
and the beginning of the function, which will be discussed later.
In the case of one rat that could hear at nine days this change
had already occurred.
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
83
 
 
 
13. The greatest height of Hensen's supporting cells. The older
authors (Kolliker and others) thought that the arch of Corti
marks the highest point of the papilla which slopes from this
point gradually outward to the cells of the zona pectinata.
Against this erroneous idea Hensen ('63) first published observations showing that the highest point is in the papilla which
ascends laterally from the outer hair cells, and then slopes
abruptly and passes over to the cells of the sulcus spiralis externus.
We term this prominence Hensen's prominence and the cells,
Hensen's supporting cells. The measurements of the height of
 
 
 
90
 
M
 
70
 
50
30
\c\
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
.-<
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
s
 
 
l
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
/
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
/
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
I'
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
i
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
|
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
\
 
 
j
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
\
 
 
1
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
\
 
 
jj
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
GE
 
i
 
 
 
 
 
 
T
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
25 50 50 100 200 300 400 50O
 
Chart 25 The greatest height of Hensen's supporting cells, table 55.
 
these cells were made along 3 3 in figure 1. Table 55 (chart
25) shows the values for the greatest vertical height of these
supporting cells according to age. At the foot of the last column
are given the ratios from 1 to 6, 1 to 12, 1 to 20, 1 to 546, 6 to 12,
6 to 20, 6 to 546, 12 to 20, 12 to 546, and 20 to 546 days. The
values diminish at the earlier stage from birth to six or nine days.
At twelve days they increase suddenly, more than doubling.
After that they increase to old age, rapidly up to twenty days
and then slowly. Here also the height increases from the base
to the apex, the most marked increase occurring between turns
II and III. In table 56 this relation is clearly shown. Retzius
('84) gets values of this height in the rabbit and cat as follows
(table 57).
 
 
 
84 ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
In both the rabbit and the cat the height increases at ten to
eleven days very considerably, as it does in the rat. Only
there is a large difference in the absolute values for the
three animals, these being largest in the rabbit and smallest
in the cat. The final average values in the cat are nearly the
same as those in the rat at the same age.
 
Kolmer ('07) finds in the calf the value in the highest point
of the organ of Corti in the region of the innermost Hensen's
cells as follows:
 
In the basal turn, 84 [A
 
In the second turn, 90 JJL
 
In the third turn, 105 [JL
 
Average, 93 [i.
 
Hensen ('63) gives in man the average height of the papilla
as 90 (JL in the hamulus and 60 [j. in the radix. Thus the height
of Hensen's cells is different in different animals.
 
When we consider the growth in the height of Hensen's cells
we can picture the change of the form in the papilla spiralis.
As shown already, the height of the pillar cells is largest at the
earlier stage, when the papilla has its highest point at the summit
of the arch of Corti, and slopes downward to the Hensen's cells.
But at twelve days the form is reversed, and the highest point
is in Hensen's prominence from which the surface slopes inward
more or less steeply to the surface of the pillar cells and the
inner supporting cells. Thus the surface of the papilla does
not run parallel to the basilar membrane, but makes with it a
sharp angle opening outward. This angle has been measured.
 
14- The angle subtended by the extension of the surface of the
lamina relicularis with the extended plane of the membrana basilaris.
As just stated, the lamina reticularis after the earlier stages
is not parallel to the membrana basilaris, but forms an angle
with it. The measurements of this angle , were taken as
shown in lines 4~4' i n figure 1. In table 58 (chart 26) are given
the values for the angle in degrees. Before nine days there is
no appreciable angle. From twelve to twenty days the angle
increases rather rapidly, and after twenty days continuously
but slowly. The ratio at the bottom of the last column shows
this clearly.
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
85
 
 
 
Comparing the values of the angle in each turn according to
age, there is no clear evidence that it increases from base to apex,
though it tends to be largest in turn III and next largest in turn
II. The condensed table 59 shows these relations. Retzius
( ; 84) finds this angle in the rabbit and cat to be as in table 60.
 
TABLE 56 Condensed
 
Ratios of the greatest height of Hensen's supporting cells according to the turns of
 
the cochlea
 
 
 
 
 
 
 
RATIOS BETWEEN SUCCESSIVE TURNS
 
 
AVERAGE AGE
 
 
AVERAGE BODY
 
 
 
 
 
 
WEIGHT
 
 
1
 
 
 
 
 
 
 
 
I-II
 
 
I-III
 
 
I-IV
 
 
days
 
 
grams
 
 
 
 
 
 
 
 
1
 
 
5
 
 
1 1.0
 
 
1 1.1
 
 
1 0.9
 
 
8
 
 
11
 
 
1.1
 
 
1.2
 
 
1.2
 
 
18
 
 
21
 
 
1.1
 
 
1.4
 
 
1.5
 
 
213
 
 
138
 
 
1.0
 
 
1.2
 
 
1.2
 
 
 
TABLE 57
Greatest height of Hensen's supporting cells in M (Retzius)
 
 
 
RABBIT
 
 
CAT
 
 
Age
Days
 
 
Basal
turn
 
 
Middle
 
 
Apical
 
 
Average
 
 
Basal
 
 
Middle
 
 
Apical
 
 
Average
 
 
Xew-born
 
 
38?
 
 
60?
 
 
50?
 
 
49?
 
 
45
 
 
50
 
 
39
 
 
45
 
 
2
 
 
55?
 
 
60?
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3
 
 
 
 
 
 
 
 
 
 
 
 
 
 
39
 
 
54
 
 
 
 
 
 
 
 
7
 
 
48
 
 
81
 
 
67
 
 
65
 
 
57
 
 
50
 
 
40
 
 
49
 
 
10
 
 
105
 
 
125
 
 
105
 
 
112
 
 
 
 
 
 
 
 
 
 
 
 
 
 
11
 
 
 
 
 
 
 
 
 
 
 
 
 
 
75
 
 
78
 
 
45
 
 
66
 
 
14
 
 
 
 
 
150
 
 
120
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
30
 
 
 
 
 
 
 
 
 
 
 
 
 
 
50
 
 
69
 
 
95
 
 
71
 
 
 
Retzius also finds in man in the basal turn 25, in the middle
35, and in the apical 23. Thus the angle always increases with
age, but has different absolute values in different mammals and
always tends to be greater in the middle turns.
 
15. Lengths of the inner and outer pillar cells. The measurements of length were taken as shown by lines 1-1, and 2-2 as in
figure 2. This does not give the total length, but the length
from the base to the point, just below the joint. As is well
 
 
 
86
 
 
 
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
 
 
TABLE 58
 
Angle of the lamina reticularis with the plane of Ihe membrana basilaris in
 
degrees, 6 (chart 26}
 
 
 
 
 
 
 
 
 
TURNS OF THE COCHLEA DEGREES
 
 
AGE
 
 
BODY WEIGHT
 
 
 
 
 
 
 
 
 
 
I
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
II
 
 
III
 
 
IV
 
 
Average
 
 
days
 
 
grams
 
 
 
 
 
 
 
 
 
 
 
 
1
 
 
5
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3
 
 
8
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
6
 
 
11
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
9
 
 
10
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
12
 
 
13
 
 
7
 
 
12
 
 
13
 
 
9
 
 
10
 
 
15
 
 
13
 
 
11
 
 
14
 
 
13
 
 
13
 
 
13
 
 
20
 
 
29
 
 
15
 
 
13
 
 
11
 
 
11
 
 
13
 
 
25
 
 
36
 
 
14
 
 
14
 
 
13
 
 
13
 
 
14
 
 
50
 
 
59
 
 
15
 
 
15
 
 
17
 
 
11
 
 
15
 
 
100
 
 
112
 
 
15
 
 
14
 
 
16
 
 
14
 
 
15
 
 
150
 
 
183
 
 
15
 
 
15
 
 
19
 
 
17
 
 
17
 
 
257
 
 
137
 
 
13
 
 
15
 
 
18
 
 
17
 
 
16
 
 
366
 
 
181
 
 
16
 
 
15
 
 
16
 
 
16
 
 
16
 
 
546
 
 
255
 
 
16
 
 
16
 
 
17
 
 
17
 
 
17
 
 
Vertical averages
 
 
 
 
13.7
 
 
14.3
 
 
15.3
 
 
13.8
 
 
 
 
 
Ratios 12 20 days 1 : 1.3
 
12546 " :1.7
 
TABLE 59 Condensed
 
Ratios of the angle of the lamina reticularis with the plane of the membrana basilaris
according to the turns of the cochlea
 
 
 
 
 
 
 
 
 
RATIOS BETWEEN TURNS
 
 
AVERAGE AGE
 
 
AVERVGE BODY
WEIGHT
 
 
I-II
 
 
 
 
I-II I
 
 
I- IV
 
 
days
12
 
 
grams
13
 
 
1 1.7
 
 
1 1.9
 
 
1 : 1.3
 
 
18
 
 
21
 
 
1.0
 
 
0.9
 
 
:0.9
 
 
213
 
 
138
 
 
1.0
 
 
1.2
 
 
:1.0
 
 
 
TABLE 60
 
Angle of the lamina reticutaris with the plane of the membrana basilaris in degrees
 
(Retzius)
 
 
 
Age
 
 
Basal
turn
 
 
Middle
turn
 
 
Apical
turn
 
 
Average
 
 
Basal
turn
 
 
Middle
turn
 
 
Apical
turn
 
 
Average
 
 
days
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
New-born
 
 
 
 
 
5?
 
 
8?
 
 
 
 
 
 
 
 
 
 
 
5? 8?
 
 
 
 
 
2
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
5? 8?
 
 
 
 
 
 
 
 
7
 
 
17
 
 
19
 
 
11
 
 
 
 
 
5
 
 
5
 
 
10
 
 
 
 
 
10
 
 
20
 
 
30
 
 
23
 
 
24
 
 
 
 
 
 
 
 
 
 
 
 
 
 
11
 
 
 
 
 
 
 
 
 
 
 
 
 
 
20
 
 
1020
 
 
 
 
 
 
 
 
14
 
 
25
 
 
50
 
 
45
 
 
40
 
 
 
 
 
 
 
 
 
 
 
 
 
 
30
 
 
 
 
 
 
 
 
 
 
 
 
 
 
18
 
 
23
 
 
20
 
 
20
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
87
 
 
 
known, the inner and outer pillar cells when mature show a more
or less S-shaped curvature, though they are straighter in the
earlier stages. Thus the length as measured in the adult cochlea
is somewhat smaller than the natural lengths.
 
 
 
DEGREES
18
 
 
 
15
 
 
 
12
 
 
 
 
 
 
 
25
 
 
 
50
 
 
 
5O 1OO 20O 300 40O 500
 
 
 
Chart 26 The angle subtended by the extension of the lamina relicularis
with the extended plane of the membrana basilaris, in degrees, table 58, fieure 1
4-4', 9
In table 61 (charts 27 to 32) is given the values for the lengths
of the inner and outer pillar cells according to age. At first we
shall consider the average values for the length of the inner
and outer pillar cells taken together. This length diminishes
at three days. From three to twelve days it increases rapidly,
 
 
 
88
 
 
 
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
 
 
and from twelve to twenty days more slowly. After twenty
days it decreases a little. The ratios at the bottom of the last
column show these relations. The familiar fact, that the length
increases from the base to the apex is clearly shown in chart 28.
 
 
 
TABLE 61
 
 
 
Lengths of the inner and outer pillar cells (without head) measured from the footplate
on the membrana basilaris to the point directly below the junction
(charts 27 to 32)
 
 
 
AOE
 
 
BODY
WEIGHT
 
 
INNER PILLAR
 
 
OUTER PILLAR
 
 
Combined
Average
 
 
Turns of the cochlea M
 
 
Turns of the cochlea M
 
 
I
 
 
II
 
 
ill
 
 
IV
 
 
Average
 
 
I
 
 
II ill
 
 
IV
 
 
Average
 
 
days
 
 
gms
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
 
 
5
 
 
28
 
 
29
 
 
29
 
 
29
 
 
29
 
 
24
 
 
27
 
 
27
 
 
26
 
 
26
 
 
28
 
 
3
 
 
8
 
 
26
 
 
23
 
 
26
 
 
23
 
 
25
 
 
19
 
 
20
 
 
20
 
 
21
 
 
20
 
 
23
 
 
6
 
 
11
 
 
35
 
 
36
 
 
36
 
 
37
 
 
36
 
 
21
 
 
26
 
 
27
 
 
26
 
 
25
 
 
31
 
 
9
 
 
10
 
 
35
 
 
39
 
 
41
 
 
40
 
 
39
 
 
26
 
 
26
 
 
29
 
 
29
 
 
28
 
 
34
 
 
12
 
 
13
 
 
33
 
 
38
 
 
44
 
 
44
 
 
40
 
 
46
 
 
59
 
 
72
 
 
72
 
 
62
 
 
51
 
 
15
 
 
13
 
 
34
 
 
38
 
 
48
 
 
51
 
 
43
 
 
44
 
 
59
 
 
74
 
 
78
 
 
64
 
 
54
 
 
20
 
 
29
 
 
43
 
 
47
 
 
56
 
 
60
 
 
52
 
 
56
 
 
65
 
 
79
 
 
83
 
 
71
 
 
62
 
 
25
 
 
36
 
 
43
 
 
47
 
 
56
 
 
60
 
 
52
 
 
53
 
 
64
 
 
80
 
 
84
 
 
70
 
 
61
 
 
50
 
 
59
 
 
42
 
 
44
 
 
55
 
 
61
 
 
51
 
 
52
 
 
64
 
 
79
 
 
84
 
 
70
 
 
*61
 
 
100
 
 
112
 
 
42
 
 
44
 
 
53
 
 
58
 
 
49
 
 
52
 
 
62
 
 
79
 
 
84
 
 
69
 
 
59
 
 
150
 
 
183
 
 
41
 
 
43
 
 
54
 
 
59
 
 
49
 
 
51
 
 
64
 
 
76
 
 
85
 
 
69
 
 
59
 
 
257
 
 
137
 
 
40
 
 
44
 
 
53
 
 
60
 
 
49
 
 
53
 
 
64
 
 
75
 
 
85
 
 
69
 
 
59
 
 
366
 
 
181
 
 
39
 
 
45
 
 
53
 
 
59
 
 
48
 
 
50
 
 
64
 
 
78
 
 
83
 
 
69
 
 
59
 
 
546
 
 
255
 
 
41
 
 
44
 
 
53
 
 
58
 
 
49
 
 
49
 
 
64
 
 
78
 
 
83
 
 
69
 
 
59
 
 
Ratios 1- 12 days
 
 
 
 
 
 
1 1.4
 
 
 
 
 
 
 
 
 
 
1 :2.4
 
 
1 : 1.8
 
 
1- 20 "
 
 
 
 
 
 
1.8
 
 
 
 
 
 
 
 
 
 
2.7
 
 
:2.2
 
 
1-546 "
 
 
 
 
 
 
1.7
 
 
 
 
 
 
 
 
 
 
2.7
 
 
:2.1
 
 
20-546 "
 
 
 
 
 
 
0.9
 
 
 
 
 
 
 
 
 
 
1.0
 
 
: 1.0
 
 
 
When we calculate the average values of the inner and outer
pillar cells from Retzius table ('84), we get the following (table
62). .
 
TABLE 62
 
Combined lengths of the inner and outer pillars from the foot plate to a point
directly below the junction in n (Retzius)
 
 
 
RABBIT (adult)
 
 
CAT (adult)
 
 
MAN (adult)
 
 
Basal
turn
 
 
Middle
turn
 
 
Apical
turn
 
 
Average
turn
 
 
Basal
turn
 
 
Middle
turn
 
 
Apical
turn
 
 
Average
 
 
Basal
turn
 
 
Middle
turn
 
 
Apical
turn
 
 
Average
 
 
66
 
 
85
 
 
78
 
 
76
 
 
55
 
 
75
 
 
73
 
 
67
 
 
55
 
 
84
 
 
87
 
 
75
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
89
 
 
 
70
 
 
 
50
 
 
 
30
 
 
 
10
 
 
 
 
 
 
 
 
25
 
 
 
50
 
 
 
5O 1OO 2OO 300 4OO 5OO
 
 
 
Chart 27 The length of inner and outer pillar cells combined, without
head, measured from the foot plate on the membrana basilaris to the point
directly below the junction, table 61, figure 2, /-/, 2-2.
 
 
 
80
 
 
 
 
 
 
 
w.q A re
 
 
 
 
 
 
 
25 50 50 JOO 200 300 4OO 5OO
 
 
 
Chart 28 The length of inner and outer pillar cells combined, without
head, measured from the foot plate on the membrana basilaris to the point
directly below the junction, according to the turns of the cochlea, table 61.
 
 
 
,u
50
 
30
 
in
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
s
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
r -'
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
J
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
GE
 
 
D
 
 
A
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
TO
 
 
 
 
 
 
25
 
 
 
5O
 
 
 
2OO
 
 
 
5(X)
 
 
 
Chart 29 The length of inner pillar cell without head, table 61, figure 2, 1-1.
 
 
 
90 ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
As table 62 shows, the values in these mammals are larger
than those in the albino rat a result which fits with our previous
observations.
 
When we consider the length of the inner pillar cells alone,
we see that the values (chart 29) here also increases from three
days to twenty days, but not so largely as in the combined values
of the inner and outer pillar cells. After twenty days the values
for the inner pillar cells decrease slightly. This relation is shown
by the ratios at the bottom of the corresponding column. That
the increase progresses from the base to the apex, being most
marked in turn III, is illustrated in chart 30. The condensed
table 63 shows those relations also. The one-day-old rat is an
exception.
 
We turn now to the growth in the length of the outer pillar
cells. As we see in table 61 (chart 31), the length of the outer
pillar cell does not increase so much from one to nine days as the
inner pillar cell did. At twelve days, however, the increase in
length is very marked, that is, 2.2 times as much as at nine days.
 
After the outer pillar cell reaches its maximum at twenty
days, it decreases only slightly with advancing age. The ratios
at the bottom of the corresponding column show this relation
clearly. The length increases from base to apex, though this
relation is not well established until twelve days, as shown in
table 61 and chart 32. The ratios of the outer pillar cells according to the turns of the cochlea are shown in table 64.
 
The inner and outer pillar cells show marked differences in
their growth. While at the earlier ages the length of the inner
is greater than that of the outer, yet after twelve days this
relation is reversed. Moreover, from nine to twelve days the
growth is gradual in the inner pillar cells, but rapid in the outer.
The condensed table 65 shows the values for the length of the
inner and outer pillar cells separately. In the last column are
given the ratios between them.
 
In the accompanying table 66 I have compared the values
obtained in the rat with those given by other authors.
 
As table 66 shows, the absolute values differ in various animals.
However, the ratios between the values for the inner and outer
 
 
 
eu
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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fir\
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
ou
 
 
 
 
 
 
 
 
 
 
/
 
 
,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
k-
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2
 
 
 
 
 
 
 
 
 
 
 
 
{/
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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:,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
A f\
 
 
 
 
 
 
i
 
 
 
 
 
j'f
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
=-fl
 
 
*HJ
 
 
 
 
 
 
A
 
 
-X
 
v
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
J
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
*-i
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
O/"
 
 
 
 
i
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
20
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
ft
 
 
p
 
 
IT
 
L
 
 
P
L
 
 
ft
 
 
vcj
 
f\
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
u
 
 
 
 
 
 
 
 
2
 
 
 
o
 
 
 
25
 
 
 
50 50 10O 200 3OO 4OO 50O
 
Chart 30 The length of the inner pillar cell without head, according to
the turns of the cochlea, table 61.
 
 
 
80
 
M
60
 
40
20
 
f\
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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f-'
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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AGE
 
i i
 
 
DAY
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
25
 
 
 
50
 
 
 
5O 1OO 200 300 4OO 50O
 
Chart 31 The length of outer pillar cells without head, table 61, figure 2,
 
 
 
IVAJ
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
M
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
RH
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
t
 
 
ou
 
 
 
 
 
 
 
 
 
 
y
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
~
 
 
"~
 
 
 
 
 
^
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
^
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
ar\
 
 
 
 
 
 
 
 
 
 
/
 
 
*
 
 
^
 
 
 
 
 
 
 
 
 
 
 
 
 
 
~
 
~
 
 
^
 
 
^
 
 
 
 
 
 
 
 
 
 
 
 
~
 
 
 
 
* *
 
 
"'
 
 
"~
 
 
 
 
 
 
 
 
 
 
 
 
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oU
 
 
 
 
 
 
 
 
<k "
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
k <
 
 
 
 
 
 
 
 
~^
 
 
_,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
>
 
 
_
 
 
*
 
 
-~
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Af\
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
n
 
 
t *
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
oo
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
^U
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
r
 
 
<~~
 
 
 
 
 
 
A
 
 
k/C
 
 
n
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
(j
 
 
 
 
 
 
 
 
1OT
 
 
 
 
 
 
 
25 50 50 1OO -OO 3OO 4OO 5OO
 
 
 
Chart 32 The length of outer pillar cells without head, according to the
turns of the cochlea, table 61.
 
91
 
 
 
92
 
 
 
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
 
 
TABLE 63 Condensed
Ratios of the length of the inner pillar cells according to the turns of the cochlea
 
 
 
AVERAGE AGE
 
 
AVERAGE BOOT
WEIGHT
 
 
RATIOS BETWEEN TURNS
 
 
I-II
 
 
I-II I
 
 
I-IV
 
 
days
1
 
 
grams
5
 
 
1 1.0
 
 
1 1.0
 
 
1 1.0
 
 
8
 
 
11
 
 
1.1
 
 
1.2
 
 
1.1
 
 
18
 
 
21
 
 
1.1
 
 
1.3
 
 
1.4
 
 
213
 
 
138
 
 
1.1
 
 
1.3
 
 
1.4
 
 
 
TABLE 64 Condensed
Ratios of the length of the outer pillar cells according to the turns of the cochlea
 
 
 
AVERAGE AGE
 
 
AVERAGE BODY
WEIGHT
 
 
RATIOS
 
 
BETWEEN TURNS
 
 
 
 
 
 
 
 
I-II
 
 
I-II I
 
 
I- IV
 
 
days
1
 
 
grams
5
 
 
1 : 1.1
 
 
1 1.1
 
 
1 1.0
 
 
8
 
 
11
 
 
:1.2
 
 
1.3
 
 
1.3
 
 
18
 
 
21
 
 
: 1.2
 
 
1.5
 
 
1.6
 
 
213
 
 
138
 
 
: 1.3
 
 
1.5
 
 
1.6
 
 
 
TABLE 65 Condensed
 
Comparison of the average length of the inner and outer pillar-cellswithout
 
head.
 
 
 
 
 
 
 
AVERAGE LENGTH OF PILLAR CELLS
 
 
 
 
AVERAGE AGE
 
 
AVERAGE BODY
 
 
WITHOUT HEAD
 
 
RATIOS OF INNER
 
 
 
 
\V V T ( ' H T
 
 
 
 
TO OUTER
 
 
 
 
 
 
Inner
 
 
Outer
 
 
 
 
days
 
 
grams
 
 
 
 
 
 
 
 
1
 
 
5
 
 
29
 
 
26
 
 
1 :1.0
 
 
8
 
 
11
 
 
35
 
 
34
 
 
:1.0
 
 
18
 
 
21
 
 
48
 
 
68
 
 
:1.4
 
 
213
 
 
13S
 
 
50
 
 
69.
 
 
: 1.4
 
 
 
pillar cells are smallest in man and in the rat and alike in the
other two forms, Retzius ('84). Hensen ('63) states that in the
base of the human cochlea both pillar cells are equally long.
Later, Pritchard ('78) supported this observation. In the
literature, however, no one except these two authors report the
inner and outer pillar cells in the base of the adult cochlea as
equal in length, but the inner is always stated to be shorter than
the outer. We may therefore say that most authors agree that
the inner pillar cells are at earlier stages longer than the outer,
then they become equal, and finally the outer surpass the inner.
 
 
 
GROWTH OF THE INNER EAR OF ALfcINO RAT
 
 
 
93
 
 
 
TABLE 66
 
Lengths of inner and outer pillars in several mammals according to different authors.
 
Measurements in n
 
 
 
INNER PILLAR
 
 
OUTER PILLAR
 
 
Authors
 
 
Animals
 
 
Basal
turn
 
 
Middle
 
 
Apical
 
 
 
 
Av.
 
 
B.
 
 
M.
 
 
A.
 
 
 
 
Av.
 
 
Ratio
 
 
Corti
 
 
Mammals
 
 
30
 
 
30
 
 
34
 
 
31
 
 
4549
 
 
54
58
 
 
69
 
 
57
 
 
1:1.8
 
 
Hensen
 
 
Man
 
 
48
 
 
 
 
 
86
(Hamul
us)
 
 
48
 
 
 
 
 
 
 
98
(Hamulus)
 
 
 
 
Ret
zius
 
Wada
 
 
Rabbit
 
 
56
 
 
60
 
 
60
 
 
59
 
 
75
 
 
110
 
 
95
 
 
93
 
 
:l.
 
 
Cat
 
 
41
 
 
54
 
 
57
 
 
51
 
 
68
62
 
 
95
 
 
89
 
 
84
 
 
:1.6
 
 
Man
 
 
48
 
 
68
 
 
70
 
 
62
 
 
100
 
 
103
 
 
88
 
 
:l.t
 
 
Albino
rat
after 20
days
 
 
I
41
 
 
II
45
 
 
III
 
54
 
 
IV
 
59
 
 
50
 
 
I
52
 
 
II
64
 
 
III
 
78
 
 
IV
 
84
 
 
70
 
 
-.1.4
 
 
 
16. Inner and outer hair cells. For a long time the inner
and the outer hair cells have been regarded as the most important
elements in the papilla spiralis. As these sense cells have a
delicate histological structure which is readily altered, the
systematic study of their growth, especially after the appearance
of hearing, is a difficult matter. Though there are some observations
on the length of these cells, detailed studies on their growth
have not been made heretofore. I have therefore endeavored
to follow the changes of their size during the postnatal period.
It is first necessary to determine the form of these cells. They
are generally described as cylindrical, but this description is
inexact. Moreover, the inner and outer hair cells are somewhat
different in shape. The former has on the surface a large oval
terminal disk, which is wide hi the spiral and narrow in the
radial direction. This narrows downwards to a thinner neck
which expands into the broader body and terminates in a more
or less round but somewhat pointed irregular end.
 
 
 
94
 
 
 
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
 
 
1600
 
y
 
1400
1200
1000
800
600
400
2OO
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
^
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
/
 
 
V
 
 
-^
 
 
^
 
 
 
 
^e
 
 
=.
 
 
'
 
 
 
 
 
 
 
 
 
 
^
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
.
 
 
 
 
 
 
 
 
k
 
 
**
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
\
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
i
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
i
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
|
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
i
 
 
i
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
-I
 
 
 
 
-1
 
 
 
 
 
 
 
 
 
 
 
_ ._ .<
 
 
 
 
 
 
 
 
 
 
 
 
 
4
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
GE
 
 
E
 
 
A
 
 
^S
 
 
 
 
ft
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
25
 
 
 
50
 
 
 
5O 100 2OO 300 4OO 5OO
 
 
 
Chart 33 The weighted volume of inner and outer hair cells combined,
and of their nuclei in cubic micra, tables 67 and 69.
 
- Weighted volume of inner and outer hair cells combined.
Weighted volume of nuclei of inner and outer hair cells combined.
 
The outer hair cells have a much more cylindrical form,
their upper terminal disk is not so wide and not round, but
hexagonal. They become a bit thin in the neck, then wide in
the body. Their lower end is rounded. In order, however, to
determine the cell volume, the cell form has been taken as that
of a cylinder. For computation, the average of the diameters
measured in three places, the end disk, neck, and cell body, was
taken as the diameter and the length of the cell as the length of
the cylinder. From these data the volume of the cylinder was
computed.
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
95
 
 
 
In table 67 are given the values for the volume of the cell
bodies in the (1) inner and (3) outer hair cells separately and
the weighted volume of both cells (in the radial section of the
rat cochlea we see one row of inner and three rows of outer
hair cells), according to age.
 
TABLE 67
 
Average volumes of the inner and outer hair cells in cubic micro
(charts 33 to 37)
 
 
 
AGE
 
 
 
 
INNER HAIR CELL
 
 
OUTER HAIR CELL
 
 
 
 
BODY
WGHt
 
 
Tu
 
I
 
 
rns of
II
 
 
the o
III
 
 
achlea
IV
 
 
fit
Average
 
 
T
I
 
 
urns o
II
 
 
f the (
III
 
 
iwlilr;
 
IV
 
 
l M 3
Average
 
 
WEIOHTD
AVERAGE
VOLUME
 
 
days
1
 
 
gms
5
 
 
1255
 
 
982
 
 
832
 
 
631
 
 
925
 
 
641
 
 
626
 
 
505
 
 
359
 
 
533
 
 
631
 
 
3
6
' 9  
12
15
20
 
 
8
11
10
13
13
29
 
 
1457
1374
1451
1553
1598
1627
 
 
1367
1451
1734
1812
1618
1764
 
 
1206
1549
1994
1910
1902
1972
 
 
913
1221
2013
2157
2128
2189
 
 
1236
1399
1798
1858
1812
1888
 
 
767
1047
914
818
815
894
 
 
928
967
1308
1210
1178
1215
 
 
867
1053
1459
1602
1595
1606
 
 
571
800
14^8
1499
1559
1960
 
 
783
967
1277
1282
1287
1419
 
 
896
1075
1407
1426
1418
1536
1293
 
 
Av. 11
 
 
14
 
 
1510
 
 
1624
 
 
1756
 
 
1770
 
 
1665
 
 
876
 
 
1134
 
 
1364
 
 
1303
 
 
1169
 
 
25
50
100
150
257
366
546
 
 
36
59
112
183
137
181
255
 
 
1540
1497
1353
1362
1345
1290
1266
 
 
1655
1611
1550
1497
1524
1561
1486
 
 
1909
1821
1744
1683
1738
1817
1772
 
 
1995
1924
2018
1917
1976
2297
2257
 
 
1775
1713
1666
1615
1646
1741
1695
 
 
834
805
837
832
873
893
831
 
 
1243
1204
1306
1150
1230
1239
1336
 
 
1539
1580
1510
1803
1555
1651
1650
 
 
1702
1906
1737
1917
1927
1844
1839
 
 
1330
1374
1348
1426
1396
1407
1414
 
 
1441
1459
1428
1473
1459
1491
1484
 
 
Av. 213
 
 
138
 
 
1379
 
 
1555
 
 
1783
 
 
2055
 
 
1693
 
 
844
 
 
1244
 
 
1613
 
 
1839
 
 
1385
 
 
1462
 
 
Ratios 1- 12 days
1- 20 "
1-546 "
20-546 "
1- 11 "
11-213 "
 
 
1 :2.0
:2.0
 
0^9
 
 
 
 
1 :2.4
:2.7
:2.7
 
:2!2
 
 
1 :2.3
:2.4
:2.4
:0.9
:2.0
 
 
 
At first we shall consider the weighted volume for the cell
bodies of the inner and outer hair cells combined (chart 33).
As table 67 shows, the volume increases continuously to the full
size at twenty days. From one to twelve days the increase is
rapid, and after that the volumes are about the same, though
somewhat fluctuating. The ratios show this relation clearly.
 
 
 
96
 
 
 
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
 
 
Condensing all age groups into three (averages in table -67),
then the relation changes somewhat. From one to eleven days
the volume increases more than 100 per cent, while from eleven
to 213 days it increases only 13 per cent.
 
 
 
JUUO
 
1800
1600
 
1400
1200
10OO
800
6OO
4OO
200
O
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
f
 
 
[
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
i
 
 
\
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
^_
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
,
 
 
*^
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
^
 
 
"*
 
 
.
 
 
-M.
 
 
-"
 
 
 
 
^-
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4*
 
 
X"
 
 
**
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
*
 
 
 
 
^
 
 
- <
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
r
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
j
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
fl
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
I
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
^
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
**'
 
 
~~
 
 
 
 
 
 
 
 
 
 
 
 
,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
~
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
"'
 
 
 
 
 
 
...
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
c
 
 
A
 
 
YS
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
25 5O 50 1OQ 2OO 300 400 500
 
Chart 34 The volume of inner hair cells and of their nuclei, tables 67 and 69.
 
Volume of inner hair cells.
Volume of nuclei of inner hair cells.
 
The data for the growth of the nuclei of the inner and outer
hair cells are presented in tables 68 and 69. The weighted
values for the diameters of the nuclei (table 68) are large at
the earlier stages, but from twelve days decrease gradually till
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
97
 
 
 
old age. In the three condensed age groups (averages) we see
the decrease of the values from birth till old age. In table 69
are given the values for the volumes of the nuclei, calculated
as spheres (chart 33).
 
 
 
M*
 
 
 
1600
 
 
 
10OO
 
 
 
600
 
 
 
400
 
 
 
V
 
 
 
AGEjDAYS
 
 
25
 
 
 
50 50
 
 
 
2OO 3OO 400 500
 
 
 
Chart 35 The volume of inner hair cells, according to the turns of the
cochlea, table 67.
 
 
 
98
 
 
 
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
 
 
The weighted values for the volumes of the inner and outer
hair cells in each turn are given in [A 3 table 70. At the bottom
of each column is given the ratio from 1 to 12, 1 to 20, 1 to 546,
and 20 to 546 days of age. While the volume at birth is largest
in turn I and smallest in turn IV, that in turn III is largest at
 
 
 
10UU
 
y
 
1400
1200
1OOO
800
60O
4OO
 
200
n
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
P*.
 
 
*^
 
 
=
 
 
MI
 
 
 
 
 
r
 
 
 
 
 
_
 
 
=
 
 
Li.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
. 1
 
 
 
 
 
 
 
 
 
 
i
 
 
\
 
 
 
 
 
 
 
 
ir -<-<
 
 
 
 
 
 
 
 
- ,
 
 
 
 
X
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
/
 
 
 
 
-
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
/
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
K
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
f
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
/
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
/
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
f
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
\
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
**'
 
 
 
 
 
 
1
 
 
j
 
 
 
 
 
 
 
 
 
 
 
.,
 
 
L_
 
 
_.
 
 
_
 
 
 
 
 
 
_
 
 
 
 
 
 
 
 
 
._
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
_
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
&
 
 
E
 
 
C
 
 
)A
 
 
YS
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
/
 
 
 
25 50 50 1OO 2OO 3OO 400 500
 
Chart 36 The volume of outer hair cells and of their nuclei, in cubic micra,
tables 67 and 69.
 
Volume of outer hair cells.
 
._. Volume of nuclei of outer hair cells.
 
six days. After nine days the volume increases always from base
to apex.
 
Comparing the weighted vo'ume in each turn according to
age, we find that the rate of increase in volume is smallest in
turn I (1.3 to 1.2) and largest in turn IV (3.9 to 4.6) (table 70).
 
In table 72 are given the weighted values for the diameters
of the nuclei of the inner and outer hair cells in each turn. They
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
99
 
 
 
increase and then decrease during the first twelve days. The rate of
decrease is largest in turn I, and smallest in turn IV, as the ratios
at the bottom of each column show. That the diameters at
 
 
 
2000
1800
1600
1400
1200
1000
800
600
400
200
A
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
.
 
 
.
 
 
 
 
 
 
i.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
',
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
'
 
 
 
 
 
 
.
 
 
.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
!
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
*
 
 
' 1
 
 
 
 
 
 
 
 
 
 
J
 
 
'
 
 
 
 
.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
,
 
 
 
 
I
 
 
\
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
.
 
 
 
 
.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
i
 
 
 
 
s
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
 
 
 
 
 
 
>,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
 
 
 
 
 
 
 
 
*s
 
 
 
 
 
 
 
 
 
 
-^
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
\
 
 
 
 
 
 
 
 
 
 
1
 
 
 
 
 
 
N
 
 
 
 
I
 
 
 
 
 
 
 
 
 
 
's.
 
 
^
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
X
 
 
1
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
s
 
 
\
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
j
 
 
 
 
'
 
 
""^
 
 
 
 
 
 
 
 
 
 
 
 
 
 
X 1
 
 
 
 
 
 
1
 
 
 
 
 
 
 
 
^
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
~*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
\
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
i>
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
,.'
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
01
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
f
 
 
 
 
 
 
/
 
 
\
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
--
 
^
 
 
-
 
f^
 
 
B
 
 
 
 
 
 
 
 
 
 
 
H.
 
 
 
 
m
 
 
 
 
.
 
 
=:
 
 
~t ~
 
 
 
 
 
 
 
 
OH
 
 
*
 
 
 
 
 
 
~<
 
 
 
 
 
 
 
 
 
 
 
 
 
^
 
 
*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
j
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
t
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
A
 
 
^GE DAVs
i i i i i
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
25
 
 
 
50
 
 
 
5O 1OO 2OO 30O 40O 5OO
 
 
 
Chart 37 The volume of outer hair cells, according to the turns of the
cochlea, table 67.
 
the later ages have about the same value in each turn, or are a
little larger in the upper than in the lower turn, is to be seen
in table 73.
 
 
 
TABLE 68
Mean diameters of the nuclei of the inner and outer hair cells in M
 
 
 
 
 
 
 
DIAMETERS NUCLEI OF THE
 
 
DIAMETERS NUCLEI OF THE
 
 
 
 
 
 
 
 
INNER HAIR CELLS
 
 
OUTER HAIR CELLS
 
 
 
 
 
 
 
 
 
 
 
 
WEIGHT
 
AGE
 
 
BODY
 
wght
 
 
Turns of the cochlea ju
 
 
Turns of the cochlea M
 
 
ED
AVERAGE
 
 
 
 
 
 
I
 
 
II
 
 
ill
 
 
IV
 
 
Average
 
 
I
 
 
II
 
 
ill
 
 
IV
 
 
Average
 
 
 
 
days
 
 
gms.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
 
 
5
 
 
8.6
 
 
8.3
 
 
7.8
 
 
7.8
 
 
8.1
 
 
7.7
 
 
8.1
 
 
7.4
 
 
7.6
 
 
7.7
 
 
7.8
 
 
3
 
 
8
 
 
8.6
 
 
8.5
 
 
8.2
 
 
7.8
 
 
8.3
 
 
8.3
 
 
8.4
 
 
8.J
 
 
7.5
 
 
8.1
 
 
8.2
 
 
6
 
 
11
 
 
8.5
 
 
8.6
 
 
8.3
 
 
8.0
 
 
8.3
 
 
8.0
 
 
8.0
 
 
8.1
 
 
7.9
 
 
8.0
 
 
8.1
 
 
c
 
 
10
 
 
8.7
 
 
8.5
 
 
8.2
 
 
8.7
 
 
8.5
 
 
76
 
 
7.9
 
 
8.4
 
 
8.2
 
 
8.0
 
 
8.1
 
 
12
 
 
13
 
 
7.6
 
 
7.7
 
 
7.5
 
 
7.9
 
 
7.7
 
 
5.8
 
 
6.5
 
 
6.8
 
 
7.4
 
 
6.6
 
 
6.9
 
 
15
 
 
13
 
 
7.5
 
 
7.5
 
 
7.7
 
 
7.9
 
 
7.6
 
 
6 1
 
 
6.6
 
 
6.8
 
 
7.0
 
 
6.6
 
 
6.9
 
 
20
 
 
29
 
 
7.0
 
 
7.3
 
 
7.6
 
 
7.8
 
 
7.4
 
 
6.0
 
 
6.4
 
 
6.9
 
 
7.3
 
 
6.6
 
 
6.8
 
 
Av. 11
 
 
14
 
 
8.0
 
 
8.0
 
 
7.9
 
 
8.0
 
 
8.0
 
 
7.0
 
 
7.3
 
 
7.5
 
 
7.6
 
 
7.3
 
 
7.5
 
 
25
 
 
36
 
 
7.3
 
 
7 2
 
 
7.2
 
 
7.1
 
 
7.2
 
 
6.0
 
 
6.3
 
 
6.3
 
 
6.5
 
 
6.3
 
 
6.5
 
 
50
 
 
59
 
 
7.0
 
 
75
 
 
7.3
 
 
7.3
 
 
7.3
 
 
6.0
 
 
6.2
 
 
6.3
 
 
6.7
 
 
6.3
 
 
6.6
 
 
100
 
 
112
 
 
6.7
 
 
7.0
 
 
7.1
 
 
7 1
 
 
7.0
 
 
5.8
 
 
6.0
 
 
6.0
 
 
6.0
 
 
5.9
 
 
6.2
 
 
150
 
 
183
 
 
6.6
 
 
6.8
 
 
7.0
 
 
7.3
 
 
6.9
 
 
6.0
 
 
6.0
 
 
6.2
 
 
6.1
 
 
6.0
 
 
6.2
 
 
257
 
 
137
 
 
6.6
 
 
6.9
 
 
7.0
 
 
7.7
 
 
7.0
 
 
5.9 16.0
 
 
6.2
 
 
6.4
 
 
6.1
 
 
6.3
 
 
366
 
 
181
 
 
7.6
 
 
7.4
 
 
7.3
 
 
7.2
 
 
7.4
 
 
5.9
 
 
6.0
 
 
6.1
 
 
6.0
 
 
6.0
 
 
6.4
 
 
546
 
 
255
 
 
6.5
 
 
6.5
 
 
6.5
 
 
7.1
 
 
6.6
 
 
5.8
 
 
6.0
 
 
6.1
 
 
6.4
 
 
6.1
 
 
62
 
 
Av. 213! 138
 
 
6.9
 
 
7.0
 
 
71
 
 
7.3
 
 
7.1
 
 
5.9
 
 
6.1
 
 
6.2
 
 
6.3
 
 
6.1
 
 
6.3
 
 
Ratios 1- 12 days
 
 
1:1. 0,|
 
 
1 :0.9|| 1 :0.9
 
 
1- 20 "
 
 
:0.9
 
 
:0.9 :0.9
 
 
1-546 "
 
 
:0.8
 
 
 
 
:O.S 0.8
 
 
20-546 "
 
 
:0.9 |
 
 
:0.9 :0.9
 
 
 
TABLE 69
Average volumes of the nuclei of the inner and outer hair cells (charts 33, 34 and 36)
 
 
 
AGE
 
 
BODY WEIGHT
 
 
VOLUME OF NUCLEUS HAIR CELLS
 
Inner Outer
 
 
WEIGHTED
VOLUMES
INNER AND OUTER
HAIR CELLS
 
 
days
 
 
gms.
 
 
M'
 
 
M
 
 
M 3
 
 
1
 
 
5
 
 
278
 
 
239
 
 
248
 
 
3
 
 
8
 
 
299
 
 
278
 
 
289
 
 
6
 
 
11
 
 
299
 
 
268
 
 
278
 
 
9
 
 
10
 
 
322
 
 
268
 
 
278
 
 
12
 
 
13
 
 
239
 
 
151
 
 
172
 
 
15
 
 
13
 
 
230
 
 
151
 
 
172
 
 
20
 
 
29
 
 
212
 
 
151
 
 
165
 
 
25
 
 
36
 
 
195
 
 
131
 
 
144
 
 
50
 
 
59
 
 
204
 
 
131
 
 
151
 
 
100
 
 
112
 
 
180
 
 
108
 
 
125
 
 
150
 
 
183
 
 
172
 
 
113
 
 
125
 
 
257
 
 
137
 
 
180
 
 
119
 
 
131
 
 
366
 
 
181
 
 
212
 
 
113
 
 
137
 
 
546
 
 
255
 
 
151
 
 
119
 
 
125
 
 
 
Ratios 1- 12 days
1- 20 "
1-546 "
20-546 "
 
 
 
1 :0.9
:0.8
:0.5
:0.7
 
 
 
:0.6
:0.6
:0.5
:0.8
 
 
 
:0.7
:0.7
:0.5
:0.8
 
 
 
100
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
101
 
 
 
The growth of the inner hair cell. The volume of the inner
hair cell table 67 (chart 34) increases with age up to twenty
 
TABLE 70
 
Weighted volumes of the inner and outer hair cells according to the turns of the
 
cochlea
 
 
 
AGE
 
 
BODY WEIGHT
 
 
TURNS OF THE COCHLEA M*
 
 
I
 
 
II
 
 
ill
 
 
IV
 
 
days
 
 
gms.
 
 
 
 
 
 
 
 
 
 
1
 
 
5
 
 
795
 
 
715
 
 
587
 
 
427
 
 
3
 
 
8
 
 
940
 
 
1038
 
 
952
 
 
657
 
 
6
 
 
11
 
 
1129
 
 
1088
 
 
1177
 
 
905
 
 
9
 
 
10
 
 
1048
 
 
1415
 
 
1593
 
 
1574
 
 
12
 
 
13
 
 
1002
 
 
1361
 
 
1679
 
 
1664
 
 
15
 
 
13
 
 
1011
 
 
1288
 
 
1672
 
 
1701
 
 
20
 
 
29
 
 
1052
 
 
1352
 
 
1698
 
 
2017
 
 
25
 
 
36
 
 
1011
 
 
1346
 
 
1632
 
 
1775
 
 
50
 
 
59
 
 
978
 
 
1306
 
 
1640
 
 
1911
 
 
100
 
 
112
 
 
966
 
 
1367
 
 
'1569
 
 
1807
 
 
150
 
 
183
 
 
965
 
 
1237
 
 
1773
 
 
1917
 
 
257
 
 
137
 
 
991
 
 
1304
 
 
1601
 
 
1939
 
 
366
 
 
181
 
 
992
 
 
1320
 
 
1693
 
 
1957
 
 
546
 
 
255
 
 
940
 
 
1374
 
 
1681
 
 
1944
 
 
 
Ratios 1- 12 days
 
 
1 : 1.3 1
 
 
1.9
 
 
1 :2.9
 
 
1 :3 9
 
 
1- 20 "
 
 
:1.3
 
 
1.9
 
 
:2.9
 
 
:4.7
 
 
1-546 "
 
 
: 1.2
 
 
1.9
 
 
:2.9
 
 
:4.6
 
 
20-546 "
 
 
:0.9
 
 
1.0
 
 
:1.0
 
 
:1.0
 
 
 
TABLE 71 Condensed
 
Ratios of the weighted volumes of the inner -and outer hair cells according to the turns
 
of the cochlea
 
 
 
 
 
 
 
BATI08 BETWEEN TURNS
 
 
AGE
 
 
BODY WEIGHT
 
 
I-II
 
 
i-ni
 
 
I-IV
 
 
days
 
 
0ms.
 
 
 
 
 
 
 
 
1
 
 
5
 
 
1 :0.9
 
 
1 :0.7
 
 
1 :0.5
 
 
8
 
 
11
 
 
:1.2
 
 
:1.3
 
 
:1.2
 
 
18
 
 
21
 
 
:1.3
 
 
: 1.6
 
 
: 1.8
 
 
213
 
 
138
 
 
:1.4
 
 
:1.7
 
 
:1.9
 
 
 
days; to nine days rapidly, then slowly. After twenty days it
decreases slowly, as do the weighted volumes of the inner and
outer hair cells, and with fluctuations, is nearly the same after
 
 
 
102
 
 
 
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
 
 
100 days. The three condensed age groups show that from
1 to 11 days it has increased 80 per cent, while from 11 to 213
days it has gained less than 2 per cent.
 
TABLE 72
 
Weighted diameters of the nuclei of the inner and outer hair cells according to the
 
turns of the cochlea
 
 
 
AGE
 
 
BODY WEIGHT
 
 
TURNS OF THE COCHLEA M
 
 
I
 
 
II
 
 
ill
 
 
IV
 
 
days
 
 
gms.
 
 
 
 
 
 
 
 
 
 
1
 
 
5
 
 
7.9
 
 
8.2
 
 
7.5
 
 
7.7
 
 
3
 
 
8
 
 
8.4
 
 
8.4
 
 
8.1
 
 
7.6
 
 
6
 
 
11
 
 
8.1
 
 
8.2
 
 
8.2
 
 
7.9
 
 
9
 
 
10
 
 
7.9
 
 
8.1
 
 
8.4
 
 
8.3
 
 
12
 
 
13
 
 
6.3
 
 
6.8
 
 
7.0
 
 
7.5
 
 
15
 
 
13
 
 
6.5
 
 
6.8
 
 
7.0
 
 
7.2
 
 
20
 
 
29
 
 
6.3
 
 
6.6
 
 
7.1
 
 
7.4
 
 
25
 
 
36
 
 
6.3
 
 
6.5
 
 
6.5
 
 
6.7
 
 
50
 
 
59
 
 
6.3
 
 
6.5
 
 
6.6
 
 
6.9
 
 
100
 
 
112
 
 
6.0
 
 
6.3
 
 
6.3
 
 
6.3
 
 
150
 
 
183
 
 
6.2
 
 
6.2
 
 
6.4
 
 
6.4
 
 
257
 
 
137
 
 
6.1
 
 
6.2
 
 
6.4
 
 
6.7
 
 
366
 
 
181
 
 
6.3
 
 
6.4
 
 
6.4
 
 
6.3
 
 
546
 
 
255
 
 
6.0
 
 
6.1
 
 
6.2
 
 
6.6
 
 
 
Ratios 1- 12 days
 
 
1 :0.8
 
 
1 :0.8
 
 
1 :0.9 1
 
 
1.0
 
 
1- 20 "
 
 
:0.8
 
 
:0.8
 
 
:0.9
 
 
1.0
 
 
1-546 "
 
 
:0.8
 
 
:0.7
 
 
:0.8
 
 
0.9
 
 
20-546 "
 
 
: 1.0
 
 
:0.9
 
 
:0.9
 
 
0.9
 
 
 
TABLE 73. Condensed
 
Ratios of the weighted diameters of the nuclei of the inner and outer hair cells
according to the turns of the cochlea
 
 
 
 
 
 
 
RATIOS BETWEEN TURNS
 
 
AVERAGE AGE
 
 
AVERAGE BODY
 
 
 
 
 
 
WEIGHT
 
 
 
 
 
 
 
 
 
 
 
 
I-II
 
 
i-m
 
 
I-IV
 
 
days
 
 
gms.
 
 
 
 
 
 
 
 
1
 
 
5
 
 
1 :1.0
 
 
1 0.9
 
 
1 1.0
 
 
8
 
 
11
 
 
:1.0
 
 
1.0
 
 
1.0
 
 
18
 
 
21
 
 
:1.0
 
 
1.1
 
 
1.1
 
 
213
 
 
138
 
 
:1.0
 
 
1.0
 
 
1.1
 
 
 
From nine days on the volume of the inner hair cell increases
in passing from the base to the apex. During the earlier stages
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
103
 
 
 
there are some fluctuations (table 67, chart 35). In the condensed table 74 the general relations are shown. The growth
of the nuclei of the inner hair cells in diameter is given in table 68.
As we see, the diameters increase from birth to nine days,
then decrease slowly but steadily. In the three average age
groups, however, the values decrease continuously with age.
In table 69 are given the values for the volumes of the nuclei
of the inner hair cell (chart 34).
 
TABLE 74 Condensed
Ratios of the volume of the inner hair cells according to the turns of the cochlea
 
 
 
 
 
 
 
RATIOS BETWEEN TURNS
 
 
AVERAGE AGE
 
 
AVERAGE BODY
 
 
 
 
 
 
WEIGHT
 
 
 
 
 
 
 
 
 
 
 
 
I-II
 
 
i-in
 
 
I-IV
 
 
days
 
 
grams
 
 
 
 
 
 
 
 
1
 
 
5
 
 
1 0.8
 
 
1 0.7
 
 
1 0.5
 
 
11
 
 
14
 
 
1.1
 
 
1.2
 
 
1.2
 
 
213
 
 
138
 
 
1.1
 
 
1.3
 
 
1.5
 
 
 
TABLE 75 Condensed
 
Ratios of the diameters of the nuclei of the inner hair cells according to the turns of
 
the cochlea
 
 
 
 
 
 
 
RATIOS BETWEEN TDRN8
 
 
AVERAGE AGE
 
 
AVERAGE BODY
 
 
 
 
 
 
WEIGHT
 
 
 
 
 
 
 
 
 
 
 
 
I-II
 
 
I-II I
 
 
I-IV
 
 
days
 
 
grams
 
 
 
 
 
 
 
 
1
 
 
5
 
 
1 1.0
 
 
1 :0.9
 
 
1 0.9
 
 
11
 
 
14
 
 
1.0
 
 
:1.0
 
 
1.0
 
 
213
 
 
138
 
 
1.0
 
 
:1.0
 
 
1.1
 
 
 
The ratios of the diameters of the nuclei of the inner hair
cells decrease at the earlier ages in each turn from the base to
the apex. After nine days they are nearly the same in all the
turns (tables 68 and 75), though their absolute values decrease
in all the turns after nine days.
 
The growth of the outer hair cells. In general, the changes in
the volume of the outer hair cells are like those in the inner
hair cells. Therefore, the volume increases strikingly up to nine
days of age, then gradually to twenty days. The main dif
 
 
104
 
 
 
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
 
 
ference is that the volume in the outer hair cells does not diminish
so much after twenty-five days, but holds nearly the same value
(table 67, chart 36). In condensed age groups, therefore, we see
a large increase in the size of the cells with age.
 
To determine the growth of the outer hair cells in each turn
of the cochlea, table 67 is used (chart 37). From twenty days on
the values increase from the basal to the apical turn. Before
twenty days the relations are irregular or reversed. In table
76 this relation is clearly brought out.
 
Comparing the changes of the volume of the outer hair cells
in three age groups (table 67), we find that the average volume
increases throughout each turn with age, except in turn I, where
 
 
 
TABLE 76 Condensed
Ratios of the volumes of the outer hair cells according to the turns of the cochlea
 
 
 
 
 
 
 
RATIOS BETWEEN TURNS
 
 
AVERAGE AGE
 
 
AVERAGE BODY
 
 
 
 
 
 
WEIGHT
 
 
 
 
 
 
 
 
 
 
 
 
I-II
 
 
i-in
 
 
I-IV
 
 
days
 
 
grams
 
 
 
 
 
 
 
 
1
 
 
5
 
 
1 1.0
 
 
1 0.8
 
 
1 0.6
 
 
11
 
 
14
 
 
1.3
 
 
1.6
 
 
1.5
 
 
213
 
 
138
 
 
1.5
 
 
1.9
 
 
2.2
 
 
 
that at eleven days is largest. In the inner hair cells, however,
values at eleven days are largest in both turn I and II.
 
For the nuclei of the outer hair cells, the diameters are given
in table 68). Here the d ! ameters tend to increase from one to
nine days. At twelve days they decrease strikingly, and after
that very slowly. In table 69 are given the values for the volumes
of the nuclei of the outer hair cells.
 
In table 68 are given also the measurements for the nuclei
of the outer hair cells according to the turn of the cochlea.
At nine days and after, the diameters become larger in passing
from base to apex, while in the earlier stages this relation is
irregular or reversed. The decrease of the measurements in,
each turn with age is clearly shown in the three age groups.
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
105
 
 
 
In table 77 are given the average ratios of turn I to the three
other turns.
 
The comparison of the growth of the inner and outer hair
cells. As already stated, the growth of the inner and outer hair
.cells in volume proceeds in about the same way till they reach
their full size at twenty days. After that we note a difference
between them. While the outer hair cells maintain a nearly
constant volume, the volume of the inner hair cells diminishes
 
TABLE 77 Condensed
 
Ratios of the diameters of the nuclei of the outer hair cells according to the turns of
 
the cochlea
 
 
 
 
 
 
 
RATIOS BETWEEN TURNS
 
 
AVERAGE AGE
 
 
AVERAGE BODY
 
 
 
 
 
 
WEIGHT
 
 
 
 
 
 
 
 
 
 
 
 
I-II
 
 
I-II I
 
 
I-IV
 
 
days
 
 
grams
 
 
 
 
 
 
 
 
1
 
 
5
 
 
1 1.1
 
 
1 1.0
 
 
1 1.0
 
 
11
 
 
14
 
 
1.0
 
 
1.1
 
 
1.1
 
 
213
 
 
138
 
 
1.0
 
 
1.1
 
 
1.1
 
 
 
TABLE 78 Condensed
Comparison of the volumes of ike inner and the outer hair cells
 
 
 
 
 
 
 
AVERAGE VOLUMES HAIR CELLS
 
 
 
 
AVERAGE AGE
 
 
AVERAGE BODY
 
 
 
 
RATIOS OF INNER
 
 
 
 
WEIGHT
 
 
 
 
 
 
TO OUTER
 
 
 
 
 
 
Inner
 
 
Outer
 
 
 
 
days
 
 
grams
 
 
M
 
 
A
 
 
 
 
1
 
 
5
 
 
925
 
 
533
 
 
1 0.6
 
 
11
 
 
14
 
 
1665
 
 
1169
 
 
0.7
 
 
213
 
 
138
 
 
1693
 
 
1385
 
 
0.8
 
 
 
somewhat with age. When we consider the volume according
to the three age groups, it increases in both groups throughout
life (table 78). There are, however, large differences in the rate
of increase. The inner hair cell increases its volume at 11 days
by 80 per cent and between 11 and 213 days by less than 2 per cent.
For the outer hair cells the increase by 11 days is 120 per cent
and from 11 to 213 days, 19 per cent. At the same time the inner
are always larger than the outer hair cells, as the ratios in table
78 show.
 
 
 
106
 
 
 
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
 
 
The diameters of the nuclei in both the inner and outer hair
cells diminish in value after nine days of age. This decrease
is larger in the outer than in the inner cells. In table 79 are
given the values for the diameters of the nuclei in both inner and
outer hah* cells. In the last column are the ratios between them.
 
Thus, while the volumes of the outer hair cells, as compared
with the inner hair cells, become relatively larger with age (table
78), the diameters of their nuclei become relatively smaller
(table 79).
 
TABLE 79 Condensed
Comparison of the diameters of the nuclei of the inner and outer hair cells
 
 
 
 
 
 
 
AVERAGE DIAMETERS OF THE
 
 
 
 
 
 
 
 
AVERAGE
 
 
NUCLEI OF THE HAIR CELLS
 
 
RATIOS OF THE AVERAGE
DIAMETERS OF THE NUCLEI OP
 
 
AVERAGE AGE
 
 
BODY
 
 
 
 
 
 
 
 
 
 
WEIGHT
 
 
Inner
 
 
Outer
 
 
CELLS
 
 
days
 
 
grams
 
 
M
 
 
M
 
 
 
 
 
 
1
 
 
5
 
 
8.1
 
 
7.7
 
 
1 1.0
 
 
 
 
11
 
 
14
 
 
8.0
 
 
7.3
 
 
0.9
 
 
 
 
213
 
 
138
 
 
7.1
 
 
6.1
 
 
0.9
 
 
 
 
 
Comparison of the growth of the inner and outer hair cells
according to sex. A careful and elaborate comparison has been
made to determine whether there are differences in the growth
of the hair cells according to sex.
 
In table 80 are given the average values for the volumes of
the cell bodies and their respective nuclei. No significant differences according to sex were found.
 
Comparison of the growth of the inner and outer hair cells
according to side. The same treatment of the data was followed
as in the determination for the influence of sex. In table 81 are
given the average values for the volumes of the inner and outer
hair cells and their respective nuclei. Again no significant
differences according to side were found.
 
On the nucleus-plasma ratios of the inner and outer hair cells.
For the inner and outer hair cells here measured the weighted
volumes of the cell bodies and of their nuclei are entered in the
condensed table 82, and the ratios of the volume of the nucleus
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
107
 
 
 
to that of the cytoplasm (=cell volume less nucleus volume)
are given in the last column. This ratio increases with age,
as table 82 shows. While the ratio is 1.5 in the youngest and
smallest group, it is 9.9 in the largest. This means that as a
group these cells are continually growing in volume. This result
may be analysed for the two groups of cells involved.
 
TABLE 80
 
Average volumes of inner and outer hair cells and of their respective nuclei
 
in n 3 according to sex
 
 
 
 
 
 
 
 
 
 
 
INNER HAIR CELLS
 
 
OUTER HAIH CELLS
 
 
WEIGHTED AVERAGE
 
 
Att
 
 
BODY
 
 
NO. OF
 
 
BEX
 
 
Average volume
 
 
Average volume
 
 
VOLUME
 
 
 
 
 
 
BATS
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Cell
 
 
Nucleus
 
 
Cell
 
 
Nucleus
 
 
CELLS
 
 
NUCLEI
 
 
da j/5
 
 
grams
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3
 
 
7
 
 
1
 
 
0*
 
 
1213
 
 
310
 
 
815
 
 
268
 
 
915
 
 
278
 
 
 
 
8
 
 
1
 
 
9
 
 
1319
 
 
310
 
 
888
 
 
322
 
 
996
 
 
319
 
 
6
 
 
11
 
 
2
 
 
tf
 
 
1426
 
 
289
 
 
955
 
 
278
 
 
1073
 
 
281
 
 
 
 
10
 
 
2
 
 
9
 
 
1372
 
 
310
 
 
979
 
 
268
 
 
1077
 
 
278
 
 
9
 
 
10
 
 
2
 
 
cT
 
 
1701
 
 
310
 
 
1351
 
 
258
 
 
1439
 
 
271
 
 
 
 
9
 
 
2
 
 
9
 
 
1895
 
 
345
 
 
1203
 
 
278
 
 
1376
 
 
295
 
 
12
 
 
14
 
 
2
 
 
c? 1
 
 
1830
 
 
258
 
 
1344
 
 
157
 
 
1466
 
 
182
 
 
 
 
12
 
 
2
 
 
9
 
 
1886
 
 
221
 
 
1221
 
 
151
 
 
1387
 
 
168
 
 
100
 
 
146
 
 
1
 
 
cT
 
 
1687
 
 
180
 
 
1342
 
 
113
 
 
1428
 
 
129
 
 
 
 
103
 
 
1
 
 
9
 
 
1779
 
 
212
 
 
1319
 
 
108
 
 
1434
 
 
184
 
 
150
 
 
189
 
 
1
 
 
rf 1
 
 
1679
 
 
165
 
 
1382
 
 
119
 
 
1456
 
 
131
 
 
 
 
154
 
 
1
 
 
9
 
 
1639
 
 
212
 
 
1611
 
 
119
 
 
1618
 
 
142
 
 
365
 
 
205
 
 
1
 
 
tf
 
 
1739
 
 
258
 
 
1389
 
 
119
 
 
1477
 
 
154
 
 
 
 
170
 
 
1
 
 
9
 
 
1659
 
 
221
 
 
1486
 
 
113
 
 
1529
 
 
140
 
 
Volume greater in male 3
 
 
2
 
 
3
 
 
4
 
 
5
 
 
3
 
 
Volume greater in female 4
 
 
4
 
 
4
 
 
2
 
 
2
 
 
4
 
 
Equal
 
 
1
 
 
 
 
 
1
 
 
 
 
 
.
 
 
 
The nucleus-plasma ratio of the inner and outer hair cells
considered separately. This is shown for the inner hair cells
in table 83. The ratios are also progressive, but somewhat
larger for the earlier age groups and smaller for the oldest, than
in the previous instance.
 
The ratios for the outer hair cells are also progressive, and
the range is greater than for the inner hair cells as table 84 shows.
Here the ratio is 1.2 for the youngest group and 10.6 for the
 
 
 
108
 
 
 
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
 
 
oldest. This indicates that at one day and eleven days the
relative volume is less in the outer than in the inner hair cells,
but at the later age the outer hairs cells grow more.
 
 
 
TABLE 81
 
 
 
Volumes of the inner and outer hair cells and of their respective nuclei according
 
to side in ft 3
 
 
 
AGE
 
 
BODY
WEIGHT
 
 
NO. OF
 
BATS
 
 
SIDE
 
 
INNER HAIR CELLS
 
 
OXJTER HAIR CELLS
 
 
WEIGHTED AVERAGE
VOLUME
 
 
Average volume
 
 
Average volume
 
 
Cell
 
 
Nucleus
 
 
Cell
 
 
Nucleus
 
 
CELLS
 
 
NUCLEI
 
 
1
 
 
5
 
 
2
 
 
R.
 
 
895
 
 
299
 
 
555
 
 
248
 
 
640
 
 
261
 
 
 
 
 
 
 
 
L.
 
 
955
 
 
268
 
 
511
 
 
230
 
 
622
 
 
239
 
 
3
 
 
7
 
 
1
 
 
R.
 
 
1213
 
 
310
 
 
815
 
 
268
 
 
915
 
 
278
 
 
 
 
 
 
 
 
L.
 
 
1395
 
 
299
 
 
920
 
 
299
 
 
1039
 
 
299
 
 
6
 
 
11
 
 
2
 
 
R.
 
 
1381
 
 
322
 
 
1010
 
 
278
 
 
1103
 
 
289
 
 
 
 
 
 
 
 
L.
 
 
1416
 
 
289
 
 
923
 
 
258
 
 
1046
 
 
268
 
 
9
 
 
9
 
 
2
 
 
R.
 
 
1782
 
 
310
 
 
1177
 
 
268
 
 
1328
 
 
278
 
 
 
 
 
 
 
 
L.
 
 
1815
 
 
333
 
 
1378
 
 
268
 
 
1487
 
 
284
 
 
12
 
 
12
 
 
1
 
 
R.
 
 
1887
 
 
212
 
 
1310
 
 
151
 
 
1454
 
 
166
 
 
 
 
 
 
 
 
L.
 
 
1885
 
 
221
 
 
1132
 
 
151
 
 
1320
 
 
168
 
 
15
 
 
13
 
 
1
 
 
R.
 
 
1895
 
 
230
 
 
1522
 
 
144
 
 
1615
 
 
165
 
 
 
 
 
 
 
 
L.
 
 
1848
 
 
239
 
 
1419
 
 
151
 
 
1526
 
 
172
 
 
20
 
 
29
 
 
2
 
 
R.
 
 
1914
 
 
212
 
 
1365
 
 
144
 
 
1502
 
 
161
 
 
 
 
 
 
 
 
L.
 
 
1862
 
 
221
 
 
1472
 
 
165
 
 
1570
 
 
179
 
 
25
 
 
36
 
 
2
 
 
R.
 
 
1758
 
 
204
 
 
1307
 
 
131
 
 
1420
 
 
149
 
 
 
 
 
 
 
 
L.
 
 
1792
 
 
195
 
 
1351
 
 
131
 
 
1461
 
 
147
 
 
50
 
 
59
 
 
2
 
 
R.
 
 
1741
 
 
204
 
 
1443
 
 
125
 
 
1518
 
 
145
 
 
 
 
 
 
 
 
L.
 
 
1687
 
 
204
 
 
1305
 
 
137
 
 
1401
 
 
154
 
 
100
 
 
102
 
 
2
 
 
R.
 
 
1675
 
 
187
 
 
1355
 
 
113
 
 
1440
 
 
131
 
 
 
 
123
 
 
2
 
 
L.
 
 
1658
 
 
172
 
 
1339
 
 
113
 
 
1419
 
 
128
 
 
150
 
 
189
 
 
1
 
 
R.
 
 
1565
 
 
172
 
 
1420
 
 
113
 
 
1456
 
 
128
 
 
 
 
 
 
 
 
L.
 
 
1679
 
 
165
 
 
1382
 
 
119
 
 
1456
 
 
131
 
 
257
 
 
137
 
 
2
 
 
R.
 
 
1685
 
 
187
 
 
1377
 
 
125
 
 
1454
 
 
140
 
 
 
 
 
 
 
 
L.
 
 
1607
 
 
180
 
 
1416
 
 
119
 
 
1464
 
 
134
 
 
367
 
 
175
 
 
2
 
 
R.
 
 
1634
 
 
195
 
 
1436
 
 
113
 
 
1486
 
 
134
 
 
365
 
 
188
 
 
2
 
 
L.
 
 
1848
 
 
230
 
 
1374
 
 
113
 
 
1493
 
 
142
 
 
546
 
 
255
 
 
2
 
 
R.
 
 
1831
 
 
157
 
 
1474
 
 
119
 
 
1563
 
 
128
 
 
 
 
 
 
 
 
L.
 
 
1559
 
 
151
 
 
1353
 
 
119
 
 
1405
 
 
127
 
 
Volume greater on right side 7
 
 
8
 
 
9
 
 
3
 
 
7
 
 
6
 
 
Volumfe greater on left side 7
 
 
5
 
 
5
 
 
5
 
 
6
 
 
8
 
 
Equal
 
 
1
 
 
 
 
 
6
 
 
1
 
 
 
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
109
 
 
 
This seems to be important and to illustrate the fact that in
the papilla spiralis the growth of the elements lying nearer the
axis occurs earlier than that of the elements nearer the periphery.
 
TABLE 82 Condensed
Nucleus-plasma ratios of the inner and outer hair cells M*
 
 
 
AVERAGE
AGE
 
 
AVERAGE
BODY
WEIGHT
 
 
AVERAGE VOLUME OF
INNER AND OUTER HAIR CELLS
 
 
VOLUME OK
CYTOPLASM
 
 
NUCLEUSFLA8MA RATIOS
 
 
Cell
 
 
Nucleus
 
 
days
 
1
 
11
 
213
 
 
grams
5
14
138
 
 
631
1293
1462
 
 
248
226
134
 
 
383
1067
1328
 
 
1 : 1.5
:4.7:9.9
 
 
TABLE 83 Condensed
Nucleus-plasma ratios of the inner hair cells /**
 
 
AVERAGE
AGE
 
 
AVERAGE
BODY
WEIGHT
 
 
AVERAGE VOLUME OF 1XXER
HAIR CELLS
 
 
VOLUME
 
or
 
CYTOPLASM
 
 
NUCLEUSPLASMA RATIOS
 
 
Cell
 
 
Nucleus
 
 
days
1
11
213
 
 
0ms.
 
5
 
14
138
 
 
925
1665
1693
 
 
278
268
187
 
 
647
 
1397
1506
 
 
1 2.3
5.2
8.1
 
 
TABLE 84 Condensed
Nude us- plasma ratios of the outer hair cells
 
 
AVERAGE
AGE
 
 
AVERAGE
BODY
WEIGHT
 
 
AVERAGE VOLUME OF OUTER
HAIR CELLS
 
 
VOLUME or
 
CYTOPLASM
 
 
NUCLEUSPLASMA
RATIOS
 
 
Cell
 
 
Nucleus
 
 
days
1
11
213
 
 
grams
5
14
138
 
 
533
1169
1385
 
 
239
204
119
 
 
294
 
965
1266
 
 
1 1.2
 
4.7
10.6
 
 
 
17. Deiters' cells. The Deiters' cells are most delicate elements. In the literature, so far as I know, there are no exact
observations touching the growth of these cells in the papilla
spiralis, except a few data for their length. They have an
 
 
 
110 ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
irregular form and consist of three parts, the phalangeal process,
cell body, and foot. The phalangeal process is thin, somewhat
crooked in the adult though it runs straight at an earlier stage.
As the boundary between this process and the cell body, we
take a line running through the supporting cup ('Stutzkelch' of
Held) parallel to the plane of the basilar membrane (fig. 10).
The cell body in its upper part is wide, including here a round
nucleus. It then becomes thin and passes over to the foot.
Thus it is almost impossible to get the true volume of the cells.
Therefore, we have determined the volume of the cell body
only, excluding that of the phalangeal process.
 
We think of the cell body as a cylinder having an average
diameter, which is calculated from four diameters measured at
four levels. The first level is just below the upper boundary
of the cell body, the second in the widest part, the third below at
about the middle of the cell body, and the last is at the narrowest
part near the foot. .
 
The height of the cylinder is the length of the cell body within
the limits just noted. Thus the volume obtained approximates
the value for the natural size of the cell body without the process.
 
In table 85 (chart 38) are given the values for the volumes of
the Deiters' cells thus computed and the diameters and volumes
of the nuclei according to age. As there are in the radial section
three rows of cells, the values given are, of course, the average
of these. At the bottom of the last column appear the ratios at
1 to 12, 1 to 20, 1 to 546, and 12 to 546 days. As we see, the
volume of the cell body increases throughout life, slowly during
the first nine days, but from twelve to twenty days very rapidly,
and then less rapidly to old age.
 
While the ratio from one to twelve days is 1:5.4, that from
1 to 546 days is 1:29.1, or more than five times as large.
 
When we consider the volumes of the cells in each turn of
the cochlea, we see that it is smallest in turn I and largest in
turn IV, though there are some exceptions before nine days
of age. Table 86 shows these relations.
 
The diameters of the nuclei of the cells grow, after some
fluctuations in the values at earlier stages, very slowly to old
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT 111
 
age, as indicated in table 85 and chart 38. The ratios at the
bottom of the corresponding column show these relations. The
values for the volumes of the nuclei of the cells are given in the
last column. Here, also, the diameters in the upper turns tend to
be larger than in the basal turn. In table 87 are given the ratios
of the diameters of turn I to the three other turns. We see in
all the turns about the same ratios, 1:1.0.
 
In the literature we find but two observations on the diameters
of the nuclei of the Dieters' cells. Kolmer ('07) reports hi the
pig 5 [i, and von Ebner ( '02) gives in man 7 (x for the diameter
of the round nucleus of the cells.
 
In the rat, therefore, the diameter is larger than in these
two forms, but no significance can be attached to this difference
until correction has been made for the several techniques employed. This I am unable at present to do.
 
On the nucleus-plasma ratio in Deiters 1 cells. In the condensed
table 88 are given the volumes of the cell bodies and of their
nuclei together with the respective nucleus-plasma ratios. This
shows that the ratio is progressive with age. While the ratio
is at birth only 0.05, that in the oldest group is 28.3. The absolute
increase is not great at earlier stages, but by eighteen days it
is marked
 
The rapid change in the ratio is very interesting. Before
eight days of age the cells are still immature. Some time after
eight days they develop rapidly, seeming to play some important
part in the special functions of the cochlea.
 
On the length of Deiters' cells. To measure the length of
Deiters' cells we divide them into two parts, the upper and the
lower, by the boundary line between the cell body and the phalangeal process. The sum of these two lengths makes the total
length of the cells.
 
In table 89 are given the values for the total length and for
each part separately (chart 39). As in the volume of the cells,
we see an astonishing change in the development of the length.
The length of the cells increases through life, at earlier stages a
little, but at twelve days it becomes nearly twice as long as at nine
days. The ratios at the bottom of the last column show the
course of growth.
 
 
 
TABLE 85
 
The volume of Deiters' cells and the mean diameters and volumes of their respective
 
nuclei (chart 38)
 
 
 
 
 
 
 
VOLUME OF THE DEITERS* CELLS
 
 
1
 
NUCLEI
 
 
VOLUMES
 
 
 
 
BODY
 
 
fit
 
 
Diameters
 
 
 
 
AGE
 
 
WEIGHT
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Average
 
 
 
 
 
 
 
 
I
 
 
II
 
 
III
 
 
IV
 
 
Average
 
 
I
 
 
II
 
 
III
 
 
IV
 
 
diam
 
Average
 
 
 
 
 
 
 
 
 
 
 
 
 
 
volume
 
 
 
 
 
 
 
 
 
 
eters
 
 
volumes
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
M
 
 
M
 
 
days
 
 
grams
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
 
 
5
 
 
278
 
 
232
 
 
237
 
 
256
 
 
251
 
 
7.6
 
 
7.5
 
 
7.5
 
 
8.1
 
 
7.7
 
 
239
 
 
3
 
 
8
 
 
290
 
 
309
 
 
349
 
 
352
 
 
325
 
 
7.0
 
 
7.0
 
 
6.9
 
 
7.0
 
 
7.0
 
 
180
 
 
6
 
 
11
 
 
425
 
 
395
 
 
495
 
 
364
 
 
420
 
 
7.0
 
 
6.5
 
 
6.7
 
 
6.6
 
 
6.7
 
 
165
 
 
9
 
 
10
 
 
635
 
 
461
 
 
554 423
 
 
518
 
 
6.9
 
 
7.0
 
 
7.1
 
 
7.1
 
 
7.0
 
 
180
 
 
12
 
 
13
 
 
1122
 
 
1369 1395
 
 
1569
 
 
1364
 
 
6.5
 
 
7.0
 
 
6.9
 
 
7.1
 
 
6.9
 
 
180
 
 
15
 
 
13
 
 
1466
 
 
2187 2659
 
 
3127
 
 
2359
 
 
7.0
 
 
7.2
 
 
7.2
 
 
7.3
 
 
7.2
 
 
195
 
 
20
 
 
29
 
 
3576
 
 
427115740
 
 
6171
 
 
4939
 
 
7.6
 
 
7.8
 
 
7.9
 
 
7.9
 
 
7.8
 
 
248
 
 
25
50
 
 
36
59
 
 
4088 4467 5470
4839 5970 6258
 
 
5757
6816
 
 
4695
5971
 
 
7.3
7.3
 
 
7.2
7.5
 
 
7.3
 
7.5
 
 
7.4
7.4
 
 
7.3
7.4
 
 
212
212
 
 
100
 
 
112
 
 
5011
 
 
6083
 
 
7137 6607
 
 
6210
 
 
6.9
 
 
7.6
 
 
7.5
 
 
7.4
 
 
7.3
 
 
212
 
 
150
 
 
183
 
 
5755 6291 7657
 
 
6750
 
 
6613
 
 
7.5
 
 
7.6
 
 
7.5
 
 
7.1
 
 
7.4
 
 
212
 
 
257
 
 
137
 
 
5776 6540 8841
 
 
8544
 
 
7425
 
 
7.4
 
 
7.8
 
 
7.9
 
 
8.0
 
 
7.8
 
 
248
 
 
366
 
 
181
 
 
6163
 
 
6908
 
 
7701
 
 
7895
 
 
7167
 
 
7.4
 
 
7.7
 
 
7.9
 
 
7.9
 
 
7.7
 
 
248
 
 
546
 
 
255
 
 
6092 6919 8028
 
 
8152
 
 
7298
 
 
7.4
 
 
7.9
 
 
8.0
 
 
7.7
 
 
7.7
 
 
248
 
 
Ratios 1 12 days
 
 
1 5.4
 
 
 
 
 
 
 
 
 
 
1 0.9
 
 
 
 
1 20 "
 
 
19.7
 
 
 
 
 
 
 
 
 
 
1.0
 
 
 
 
1546 "
 
 
29.1
 
 
 
 
 
 
 
 
 
 
1.0
 
 
 
 
12546 "
 
 
5.4
 
!
 
 
 
 
 
 
 
 
 
 
1.1
 
 
 
 
 
TABLE 86 Condensed
Ratios of volumes of the Deiter's cells according to turns of the cochlea
 
 
 
 
 
 
 
RATIOS BETWEEN TURNS
 
 
AVERAGE AGE
 
 
AVERAGE BODY
 
 
 
 
 
 
WEIGHT
 
 
 
 
 
 
 
 
 
 
 
 
I-II
 
 
i-m
 
 
I-IV
 
 
days
 
 
grams
 
 
 
 
 
 
 
 
1
 
 
5
 
 
1 :0.8
 
 
1 :0.9
 
 
1 :0.9
 
 
8
 
 
11
 
 
:1.0
 
 
: 1.1
 
 
: 1.1
 
 
18
 
 
21
 
 
: 1.3
 
 
: 1.7
 
 
: 1.8
 
 
213
 
 
138
 
 
: 1.1
 
 
: 1.4
 
 
: 1.3
 
 
 
TABLE 87 Condensed
Ratios of the diameters of the nuclei of Deilers' cells according to turns of the cochlea
 
 
 
 
 
 
 
RATIOS BETWEEN TURNS
 
 
AVERAGE AGE
 
 
AVERAGE BODY
 
 
 
 
 
 
WEIGHT
 
 
 
 
 
 
 
 
 
 
I-II
 
 
I-III
 
 
I-IV
 
 
days
 
 
grams
 
 
 
 
 
 
 
 
1
 
 
5
 
 
1 1.0
 
 
1 1.0
 
 
1 : 1.1
 
 
8
 
 
11
 
 
1.0
 
 
1.0
 
 
: 1.0
 
 
18
 
 
21
 
 
1.0
 
 
1.0
 
 
:1.0
 
 
213
 
 
138
 
 
1.0
 
 
1.1
 
 
:1.0
 
 
 
112
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
113
 
 
 
90OO
 
 
 
8OOO
 
 
 
7OOO
 
 
 
6000
 
 
 
5000
 
 
 
4000
 
 
 
3OOO
 
 
 
2OOO
 
 
 
1OOO
 
 
 
 
 
 
 
AGE
 
 
 
o
 
 
 
25
 
 
 
50
 
 
 
50 1OO 2OO 300 4OO 5OO
 
 
 
Chart 38 Showing the volume of Deiters' cells and their nuclei, on the
average and according to the turns of the cochlea, table 85.
Average volume of Deiters' cells.
 
._. Volume of the cells in about the middle of the basal turn.
 
Volume of the cells in about the beginning of the middle turn.
 
Volume of the cells in about the middle of the middle turn.
 
-..-..-.. Volume of the cells in about the beginning of the apical turn.
-...-.. Average volume of nuclei of Deiters' cells, X 10.
 
 
 
114
 
 
 
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
 
 
Comparing the length of the cells according to the turn of
the cochlea, we find that after twelve days the length increases
from the base to the apex, in turn III very rapidly, in turn IV
gradually (table 90). At earlier stages the relations are irregular.
 
 
 
TABLE 88 Condensed
Nucleus-plasma ratios of the Deiters' cells
 
 
 
 
 
 
 
AVERAGE VOLUMES
 
 
 
 
 
 
 
 
 
 
 
 
VOLUME OF
 
 
NUCLEUS
 
AVERAGE AGE
 
 
AVERAGE BODY
 
 
 
 
 
 
CYTOPLASM
 
 
PLASMA RATIOS
 
 
 
 
WEIGHT
 
 
Cell
 
 
Nucleus
 
 
.M
 
 
 
 
 
 
 
 
M
 
 
M
 
 
 
 
 
 
days
 
 
grams
 
 
 
 
 
 
 
 
 
 
1
 
 
5
 
 
251
 
 
239
 
 
12
 
 
1 : 0.05
 
 
8
 
 
11
 
 
657
 
 
172
 
 
485
 
 
: 2.8
 
 
18
 
 
21
 
 
3649
 
 
221
 
 
3428
 
 
: 15.5
 
 
213
 
 
138
 
 
6483
 
 
221
 
 
6262
 
 
:28.3
 
 
 
TABLE 89
 
Length of cell body and of processus phalangeus of Deiters' cells p (chart 39)
 
 
 
 
 
 
 
LENGTH OF THE CELL BODY
 
 
LENGTH OF THE PROCESSUS
 
 
 
 
 
 
 
 
 
 
PHALANGEUS
 
 
 
 
 
 
 
 
 
 
 
 
TOTAL
 
 
 
 
BODY
 
 
 
 
 
 
LENGTH
 
 
AGE
 
 
WEIGHT
 
 
Turns of cochlea
 
 
Turns of cochlea
 
 
OF THE
 
 
 
 
 
 
 
 
 
 
CELLS
 
 
 
 
 
 
I
 
 
II
 
 
III
 
 
IV
 
 
Average
 
 
I
 
 
II
 
 
ill
 
 
IV
 
 
Average
 
 
 
 
 
days
 
 
gms
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
 
 
5
 
 
8
 
 
8
 
 
8
 
 
9
 
 
8
 
 
20
 
 
19
 
 
20
 
 
15
 
 
19
 
 
27
 
 
3
 
 
8
 
 
8
 
 
9
 
 
9
 
 
10
 
 
9
 
 
16
 
 
17
 
 
18
 
 
18
 
 
17
 
 
26
 
 
6
 
 
11
 
 
9
 
 
9
 
 
11
 
 
10
 
 
10
 
 
19
 
 
22
 
 
23
 
 
22
 
 
22
 
 
32
 
 
9
 
 
10
 
 
18
 
 
12
 
 
13
 
 
11
 
 
14
 
 
18
 
 
21
 
 
26
 
 
24
 
 
22
 
 
36
 
 
12
 
 
13
 
 
31
 
 
35
 
 
40
 
 
43
 
 
37
 
 
18
 
 
22
 
 
29
 
 
25
 
 
24
 
 
61
 
 
15
 
 
13
 
 
34
 
 
37
 
 
40
 
 
43
 
 
39
 
 
21
 
 
25
 
 
32
 
 
31
 
 
27
 
 
66
 
 
20
 
 
29
 
 
39
 
 
41
 
 
49
 
 
49
 
 
45
 
 
19
 
 
23
 
 
30
 
 
34
 
 
27
 
 
72
 
 
25
 
 
36
 
 
42
 
 
43
 
 
51
 
 
51
 
 
47
 
 
17
 
 
21
 
 
30
 
 
32
 
 
25
 
 
72
 
 
50
 
 
59
 
 
41
 
 
45
 
 
53
 
 
53
 
 
48
 
 
16
 
 
22
 
 
30
 
 
34
 
 
26
 
 
74
 
 
100
 
 
112
 
 
43
 
 
45
 
 
54
 
 
53
 
 
49
 
 
17
 
 
25
 
 
29
 
 
31
 
 
26
 
 
75
 
 
150
 
 
183
 
 
45
 
 
46
 
 
53
 
 
52
 
 
49
 
 
17
 
 
22
 
 
32
 
 
34
 
 
26
 
 
75
 
 
257
 
 
137
 
 
43
 
 
46
 
 
56
 
 
58
 
 
51
 
 
18
 
 
24
 
 
28
 
 
31
 
 
25
 
 
76
 
 
366
 
 
181
 
 
43
 
 
48
 
 
55
 
 
55
 
 
50
 
 
17
 
 
23
 
 
29
 
 
32
 
 
25
 
 
75
 
 
546
 
 
255
 
 
46
 
 
49
 
 
56
 
 
56
 
 
52
 
 
16
 
 
23
 
 
30
 
 
33
 
 
26
 
 
78
 
 
Ratios 1 12 days
 
 
 
 
1 :4.6
 
 
 
 
 
 
 
 
 
 
1 :1.3
 
 
1 :2.3
 
 
1 20 "
 
 
 
 
:5.6
 
 
 
 
 
 
 
 
 
 
: 1.4
 
 
:2.7
 
 
1546 "
 
 
 
 
:6.5
 
 
 
 
 
 
 
 
 
 
:1.4
 
 
:2.9
 
 
12546 '"
 
 
 
 
: 1.4
 
 
 
 
 
 
 
 
 
 
:1.1
 
 
: 1.3
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
115
 
 
 
When we consider the length of the cell body, it is remarkable
that the increase takes place so rapidly. While at 1 day it
measures only 8 (x and at nine days only 14 ji, it increases very
suddenly at twelve days of age, and after that slowly but continuously (table 89).
 
TABLE 90
Total length of Deiters' cells according to turns of the cochlea (chart 39)
 
 
 
AGB
 
 
BOOT WEIGHT
 
 
TURNS OF THE COCHLEA
 
 
I
 
 
II
 
 
III
 
 
IV
 
 
days
 
 
grams
 
 
 
 
 
 
 
 
 
 
1
 
 
5
 
 
28
 
 
27
 
 
28
 
 
24
 
 
3
 
 
8
 
 
24
 
 
26
 
 
27
 
 
28
 
 
6
 
 
11
 
 
28
 
 
31
 
 
34
 
 
32
 
 
9
 
 
10
 
 
36
 
 
33
 
 
39
 
 
35
 
 
12
 
 
13
 
 
49
 
 
57
 
 
69
 
 
68
 
 
15
 
 
13
 
 
55
 
 
62
 
 
72
 
 
74
 
 
20
 
 
29
 
 
58
 
 
64
 
 
79
 
 
S3
 
 
25
 
 
36
 
 
59
 
 
64
 
 
81
 
 
83
 
 
50
 
 
59
 
 
57
 
 
67
 
 
83
 
 
87
 
 
100
 
 
112
 
 
60
 
 
70
 
 
83
 
 
84
 
 
150
 
 
183 '
 
 
62
 
 
68
 
 
85
 
 
86
 
257
 
 
137
 
 
61
 
 
70
 
 
84
 
 
89
 
 
366
 
 
181
 
 
60
 
 
71
 
 
84
 
 
87
 
 
546
 
 
255
 
 
62
 
 
72
 
 
86
 
 
89
 
 
 
80
M
60
 
40
 
20
n
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
^
 
 
<
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
="
 
 
 
 
 
 
 
>
 
 
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/
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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,/
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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ft
 
 
G
 
 
E
 
 
DA
 
 
*/c
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Tb
 
 
 
25 50 50 10O 200 30O 400
 
Chart 39 The length of Deiters' cells, tables 89 and 90.
 
 
 
500
 
 
 
Total length of the cells.
Length of the cell bodies.
Length of processus phalangeus.
 
 
 
116
 
 
 
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
 
 
In the ratios at the bottom of table 89 this is shown very
evidently and in each turn this relation is to be seen.
 
For the length of the phalangeal process the story is quite
different. It increases from birth to twelve days a little; at
fifteen days it reaches full size, and then holds its value (table 89) .
After three days the length is smallest in turn I and largest in
turn IV. This relation lasts to old age.
 
Comparing the growth of the length of the cell body and
phalangeal process, there is a large difference between them.
While the length in the phalangeal process is at birth over twice
that of the cell body, at 546 days it is only half that of the cell
 
TABLE 91
 
Total length of Deiters' cells in fj, (Retzius)
 
 
 
AGE
 
 
 
 
RABBIT
 
 
CAT
 
 
 
 
Basal
 
 
Middle
 
 
Apical
 
 
Average
 
 
Basal
 
 
Middle
 
 
Apical
 
 
Average
 
 
 
 
turn
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
New-born
 
 
48
 
 
70
 
 
60
 
 
59
 
 
45
 
 
65
 
 
48
 
 
53
 
 
2
 
 
45
 
 
66
 
 
54
 
 
55
 
 
 
 
 
 
 
 
 
 
 
1
 
 
3
 
 
 
 
 
 
 
 
 
 
 
 
 
 
45
 
 
60
 
 
 
 
 
 
 
 
7
 
 
80
 
 
90
 
 
75
 
 
82
 
 
49
 
 
69
 
 
63
 
 
60
 
 
10
 
 
98
 
 
100
 
 
114
 
 
104
 
 
 
 
 
 
 
 
 
 
 
 
 
 
11
 
 
 
 
 
 
 
 
 
 
 
 
 
 
75
 
 
90
 
 
45
 
 
70
 
 
14
 
 
84
 
 
105
 
 
112
 
 
100
 
 
 
 
 
 
 
 
 
 
 
 
 
 
30
 
 
 
 
 
 
 
 
 
 
 
 
 
 
54
 
 
75
 
 
70
 
 
66
 
 
 
body. Thus the increase of the total length of Deiters' cells
is due chiefly to the increase in the length of the cell body.
 
Retzius ('84) gives the length of Deiters' cells in the rabbit
and cat as in table 91.
 
Table 91 shows that in both the rabbit and the cat the length
at all ages is greater, and especially at the earlier stage is twice
as great, as in the rat. In the rabbit there is a rapid increase
in length between seven and ten days. For the cat the values
are smaller, nearer those of the rat, and show less change between
birth and thirty days.
 
18. Summary and discussion. Using the foregoing data on
the form and measurements of the elements of the cochlear
duct, I desire here to summarize the results and to discuss the
consequent changes in the form of the organ of Corti (table 92).
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT 117
 
We have already noted that at birth the greater epithelial
ridge constitutes the main part of the tympanic wall, and the
lesser epithelial ridge, from which arises later the most important
organ, is represented by a small and undeveloped prominence.
With age this greater ridge disappears gradually and is transformed into a furrow lined with low epithelial cells, the sulcus
spiralis internus (Waldeyer). These changes appear first at the
base and then pass gradually to the upper turns. In the lesser
ridge also there are important developmental changes. At first
the hair cells and pillar cells grow, and just before the special
function appears, striking changes are seen in Deiters' and
Hensen's cells. These increase, especially in their length, very
rapidly.
 
Thus the papilla spiralis, which hitherto had its highest
point at the summit of the arch of Corti, shows a remarkable
change of form, as the outer part of the papilla increases its
height, so that finally Hensen's cells mark the highest point
in the papilla. The surface then ceases to be parallel to the
basilar membrane, and slopes inward, making with the basilar
membrane an acute angle opening outward. At the same time
the papilla spiralis appears to be shifted inward i.e., towards
the axis.
 
Kolliker has described how the cells, from which the pillars or
rods of Corti arise, at first stand nearly parallel, but later separate
at their base. He thought that this "von einem Langenwachstum (?) der Zellen selbst oder ihrer Grundlage, der Membrana basilaris, abhiingen kann. "
 
Hensen ('63) first studied this interesting problem in the ox
and found it to depend on a peculiar process. He regarded the
inward migration as taking place chiefly in the inner pillar cell.
The outer pillar cell in the upper turn moves somewhat outward ;
in the base, however, inward. Moreover, the outer pillar cell
increases its length during the development of the papilla much
more than the inner does. Thus the summit of the arch of Corti
and therefore the papilla spiralis shifts inward on the basilar
membrane.
 
 
 
118
 
 
 
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
 
 
 
 
 
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Radial distance betw
habenula perforata
Breadth of membran!
(table 9)
 
 
Breadth of membran
(table 4)
 
 
Thickness (table 4)
 
 
jj
 
1
 
|i
 
/. -_
 
3
 
 
From hab. perf. to 01
Distance between thi
 
 
5
5
 
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c/.
 
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GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
119
 
 
 
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COC^ lOCOCO-^'H (Ni-i
 
 
 
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CO W
 
 
 
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120
 
Bottcher ( '69. 72) disagreed with Hensen, though he has confirmed, as did Middendorp ('67), the striking inward spreading
of the base of the inner pillar cell.
 
Gottstein] ( 72) held that the inner pillar cell does not move
inward, but that the increase in the length of the labium tympanicum may explain the peculiar approach of the habenula
perforata to the arch of Corti.
 
Retzius ('84) agreed in general with Hensen 's assertion that
in the course of development the surface of the sense organ
comes to lie under the basal surface of the membrana tectoria.
He thought that this change of position is brought about "weniger in dem Verhalten der Pfeilerzellen, sondern vor allem in
dem starken Wachstum der Deitersschen Zellen und der von
aussen andriickenden Hensenschen Stiitzzellen, ' and that,
further, "vielleicht die Membrana tectoria selbst durch eigenes
Wachstum und durch Vergrosserung des Limbus mit seinem
Vorspriingen" contributes to this.
 
Held ('09) agrees with Hensen on the whole.
 
Prentiss ('13, p. 450) denies the wandering of the spiral organ
as follows: ''There is no necessity for, and my preparations
afford no proof of, an inward shifting of the spiral organ and
a consequent displacement of the membrana tectoria "
 
Hardesty ('15, pp. 60 and 61) discussed the relative position
of the spiral organ with reference to the basal surface of the
tectorial membrane and says " the developed spiral organ acquires
its position well under the basal surface of the tectorial membrane
almost entirely by being carried axisward during the completion
of the membrane." "In the apical turn, where these changes
are greatest, the hair cells of the organ may be carried axisward
a distance nearly half the width of the membrane. The upgrowth
of the outer supporting cells also forces axisward the apical
ends of the elements of the spiral organ and in this way contributes a small part to the shift in the relative position of the
hair cells. A slight increase in width of the vestibular lip of
the spiral limbus may contribute a still smaller part by extending
the membrane outward."
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT 121
 
I obtained from the measurements given in the tables the
following results concerning the position of the papilla spiralis
under the basal surface of the tectorial membrane.
 
As already stated, since the habenula perforata may be considered after birth as a punctum fixum (Hensen), it is found
that the inner pillar cell shifts inward at its inner basal corner
during the earlier stage of life. At six days of age it almost
always reaches the habenula perforata in the basal turn, though
not yet in the apical. At nine days there is no distance between
the- habenula perforata and the inner corner of the inner pillar
cell.
 
Gottstein's assumption (no measurements) that the labium
tympanicum grows outward and approaches to the arch of Corti
is not applicable to the rat, as shown by my tables.
 
The outer pillar cell also moves outward in all the turns
through life, but only slightly after nine days. This result does
not agree with that of Hensen ('63), who found in the ox the
outer pillar cell to move inward a little at the base, not at all
in the middle turn and outward at the apex. Bottcher 's outward
movement of the outer pillar cell at the hamulus in the cat is
90 y. and much larger than in the rat.
 
Contrary to Hensen, Retzius ('84) also finds in the rabbit an
outward movement of the base of the outer pillar cell throughout
all the turns. On the other hand, during the earlier stages of
development, the top of the arch of Corti moves outward from
the labium vestibulare through the outward pressure of the
greater epithelial ridge. At this stage the main part of the
membrana tectoria does not yet reach to the sense cells, though
the part produced from the lesser epithelial ridge spans the
spiral organ and connects with the outer part of the papilla.
 
After nine days of age the condition of the organ is quite
different. The most remarkable anatomical changes from the
earlier condition are the rapid increase in the length of the outer
pillar cells, in the height of the pillar cells above the basilar
membrane, in the height of the papilla spiralis at the third series
of the outer hair cells, in the height of Deiters' cells, and in the
height of Hensen 's supporting cells. Also the tunnel of Corti
appears.
 
 
 
122 ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
The greater epithelial ridge has already disappeared in large
part and been replaced by a furrow. Pressure displacement
of tissue in the direction of the least resistance is common in
organogenesis. Thus the inner pillar cell is subject to pressure
by the rapid growth of the outward lying and greater part of
the papilla spiralis and moves in the direction of the least resistance, therefore inward; the head most and the base not at all.
As shown in table 44, the rapid decrease in the radial distance
between the labium vestibulare and the head of the inner pillar
cell is very evident. The arch of Corti changes its form, now
inclining inward, instead of outward as heretofore. The lamina
reticularis runs not parallel to the basilar membrane, but ascends
outward. The tunnel of Corti also changes more or less its form.
Nuel 's space now appears possibly as a result of this displacement
of the papilla spiralis. Thus we see a change in the position
of the sense organ with reference to the membrana tectoria.
 
With the inward shifting of the papilla, the hair cells come
under the basal surface of the membrana tectoria. It is probable
that the increase of the relative length of the membrane also
takes part in this, since the increase in the breadth of the inner
zone of the membrana tectoria from one to twelve days is as
1:3.4 (table 4), while the increase in the breadth of the basilar
membrane is as 1:0.5 during the same interval (table 7).
 
Prentiss' ('13) statement that an inward shifting of the papilla
spiralis and a consequent displacement of the membrana tectoria
does not take place (in the pig) is not applicable to the rat.
 
In the rat the labium vestibulare and the inner edge of the
head of the inner pillar cell are also two definite points in the
same sense, and using them we see an inward shifting of the
organ of Corti. I imagine that his observation may have misled
him, since the tectorial membrane arises in his preparations
from both greater and lesser epithelial ridges, and from the
earlier stages covers with its outer part the papilla spiralis.
Thus the shifting of the organ inward does not necessitate a
change in the position of the papilla with reference to the membrane. In his study of the tectorial membrane in the same
animal (pig) , Hardesty ( ' 13) describes a large displacement of the
papilla spiralis inward.
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT 123
 
According to him, the shifting of the organ consists of, 1, the
moving axisward of the organ itself, and this constitutes the
main shift; 2, the upgrowth of the outer supporting cells, and
this contributes a small part to the shift, and, 3, a slight increase
of the vestibular lip of the spiral limbus which may contribute
a still smaller part. The relation in the rat, however, is different.
The moving inward of the papilla itself is not seen in the rat.
In the earlier stages the inner basal corner of the inner pillar
cell alone shifts inward and reaches the habenula perforata.
On the other hand, the outer pillar cell moves outward and
the head of the inner pillar cell also, at earlier stages, towards
the cells of Hensen. Therefore, during the earlier stages the
arch of Corti moves rather outward, owing to the pressure of
the growth of the greater epithelial ridge. Since the habenula
perforata is to be regarded as a fixed point, the inward displacement of the head of the arch of Corti and of the papilla spiralis
is not due to the active shifting inward of the organ itself, as
Hardesty ('15) thinks, but to the disappearance of the greater
ridge and the passive pressure exerted by the upgrowth of the
outer pillar cells and Deiters' and Hensen 's cells. The vestibular
lip of the spiral lamina and the tectorial membrane itself both
increase in their length a little, and these increases play some
part in the change of the position of the papilla spiralis with
reference to the basal surface of the tectorial membrane.
 
The membrana basilaris is not concerned with the moving
inward of the organ. It increases its length with age in all the
turns, but we do not find the change in the position of the feet
of the pillar cells on the membrane in such a sense that the
feet move inward on it.
 
Thus the shifting of the papilla spiralis inward in the rat
during the development takes place rather in the manner described by Retzius.
 
Hardesty ('15) states that in the apical turn of the cochlea the
organ may be moved axisward a distance equal to about half
the maximum width of the greater epithelial ridge, the maximum
width of the ridge representing approximately the width of the
outspanning zone of the membrane produced upon it.
 
 
 
124
 
 
 
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON




0.43 0.03


No other author reports such a high degree of the inward
shifting of the organ. I have not studied the pig, but in the
rat I get the average distance between the labium vestibulare
and the inner edge of the head of the inner pillar cell as follows
(table 93).


TABLE 93
4.7 0.36


Average distance between the labium vestibulare and the inner edge of the inner
pillar cell in n (albino rat)




2. The ganglion cells grow relatively rapidly after birth and
reach at twenty days of age their maximum size. After having
passed the maximum at twenty days, they diminish in size
very slowly, but the internal structure matures more and more
with successive age.


AGE
3. The nuclei are relatively large at birth but increase more
slowly than the cell bodies do; nevertheless, they follow the
same course of development as the latter. This peculiar course
in the growth of the ganglion cells is similar to that followed
by the cells of the lamina pyramidalis of the cerebral cortex
of the rat as found by Sugita ('18)




BODY WEIGHT
4. Within the cochlea the cell bodies and nuclei increase
their diameters from the base toward the apex, except in the
earlier stages.


5. There are no evident differences in the diameters of the
cell bodies and the nuclei of the ganglion cells either according
to sex or side.


TURNS OF COCHLEA
6. Both the cell bodies and the nuclei are immature at birth,
but differentiate rapidly, and even at six days the Nissl bodies
are visible. The differentiation proceeds with advancing age.


7. The ganglion cells are bipolar and oval in shape. The
direction of the long axis of the cells differs according to the
turn of the cochlea and in the upper turn it runs almost parallel
to the axis of the modiolus but inclines more and more to the
horizontal position on passing to the base.


I
8. The nucleus-plasma ratios of the ganglion cells increase
with age in both the radial and cross-sections.


9. The increase in the volume of the ganglion cells and the
area of the cross-section of the hair cells is approximately sim-
ilar during the first nine days of life, but after that the ganglion
cells increase relatively very rapidly. These relations are very
different from those found for the spinal ganglion cells by Don-
aldson and Nagasaka ('18) and for the cells of the gasserian
ganglion by Nittono ('20).


II
The nervus cochlearis innervates not only the hair cells, but
 
all the elements of the cochlea, and this may have some in-
 
fluence upon this relation. It is interesting to note that the  
III
rate of increase in the cylindrical surface of the hah* cells is
 
similar to that in the area of the cross-sections of these same
 
cells.
IV
 
 
Average
 
 
days
 
 
grams
 
 
 
 
 
 
 
 
 
 
 
 
(1) 5
(2) 154
Difference betw
1 and 2
 
 
9
102
een age groups
 
 
94
 
63
31
 
 
124
100
24
 
 
1,54
134
20
 
 
165
 
148
17
 
 
23
 
 
 
Therefore, in the rat the organ moves inward on the average
of 23 [A; that is, in the ratio of 1:0.16 of the maximum distance
between these two points. It may be noted that the difference
in this table is not the same in the several turns, but diminishes
from base to apex a relation which is the reverse of that reported
by Hardesty ('15) in the pig. I have no explanation for these  
differences except their possible dependence on the different
animals used.

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Wada T. Anatomical and physiological studies on the growth of the inner ear of the albino rat. (1923) Memoirs of the Wistar Institute of Anatomy and Biology, No. 10, Philadelphia.

Rat Inner Ear (1923): I. Cochlea growth | II. Inception of hearing and cochlea growth | III. Growth of largest nerve cells in ganglion vestibulare | Final Summary | Literature Cited

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Anatomical and Physiological Studies on the Growth of the Inner Ear of the Albino Rat

I. On the Growth of the Cochlea

As noted above, I have selected from at least seven serially sectioned cochleas in each age group, four for this study, taking one section in good condition from each labyrinth. From these four sections the average values were taken for each age. Table 1 gives the data for the rats used here. As we see, sometimes two, sometimes three animals were used at each age to get the four best-prepared sections which corresponded. Determinations accordingly to sex and side, therefore, cannot be based on like numbers.

In the following text we shall often refer to the I, II, III and IV turns of the cochlea. This calls for a word of explanation. As the cochlea of the rat has nearly 2^ complete turns, four cochlear canals are usually obtained in the radial vertical sections, as prepared by me (fig. 3). Therefore, turn I does not mean the first complete turn, but about the middle part of the basal turn; turn II about the beginning of the middle turn; turn III about the middle part of the middle turn, and turn IV about the beginning of the apical turn of the cochlea. Usually the cochlea has been divided for description by the authors into the first, second, and third turns, or more definitely into the basal, middle, and apical turns. For the purpose of this study, however, it is desirable to adopt the divisions given above, because here measurements are largely employed, and there are some differences in size, volume, and arrangement of structures, even between the beginning and end of the same turn.

At all events, it is to be kept in mind that such divisions are arbitrary, as the changes in the elements take place in a graded manner.


A. On the growth of the radial distance between the two spiral ligaments

(fig. 3, 1-1, 2-2)

As we have usually four sections of the ductus cochlearis, therefore four spiral ligaments in one radial vertical section, there are two radial distances presented, the first, figure 3, 1-1, connecting the two basal sections of the ductus on opposite sides, and the second, figure 3, 2-2, connecting the two apical sections. These distances measure the radial breadth of the membranous cochlea and of the modiolus combined at these levels.


Online Editor - TABLE 1 (to be formatted) 
TABLE 1

Data on the albino rats used for the study of the cochlea


AGE


BODY WEIGHT


BOOT LENGTH


BEX


SIDE


HEARING


days


grams


mm.


1


5.3


48


d"


R. L.


1


4.2


47


o"


R. L.



3


8.8


60


a"


R.



3


7.1


54


o"


R. L.



3


8.2


56


9


R.



6


10.2


64


9


R. L.



6


11.0


62


tf


R. L.



9


9.1


58


9


R. L.



9


9.8


57


tf


R. L.


=fc


12


13.0


70


a 1


L.


+


12


11.9


68


9


R. L.


+


12


14.8


72


d"


L.


+


15


13.0


74


0"


R.


+


15


13.5


75


9


R.


+


15


13.0


74


9


R. L.


+


20


30.0


96


cf


R. L.


+


20


28.0


94


c?


R. L.


+


25


38.4


107


9


R. L.


+


25


34.2


101


9


R. L.


+


50


60.0


128


9


R. L.


+


50


57.5


121


9


R. L.


+


100


145.6


176


a 1


L.


+


100


102.5


154


9


R.


+


100


100.5


152


9


R. L.


+


150


153.5


184


9


R.


+


150


188.9


191


d 1


R. L.


+


150


198.8


192


<?


R.


+


250


133.5


178


9


R. L.


+


263


140.3


171


9


R. L.


+


365


205.4


202


0"


L.


+


365


170.4


182


9


R. L.


+


368


179.0


196


9


R.


+


546


282.1


222


<?


R. L.


+


546


227.1


204


rf


R. L.


+



In table 2 (chart 1) are entered the values for the radial distances found between the two spiral ligaments in fourteen age groups, from one to 546 days. As we see, the average value of the two distances grows rapidly from birth till six days of age. After that period the value increases gradually till twenty days, while after twenty days the increase is very slight indeed. The ratios between 1 and 12, 1 and 20, and 1 and 546 days show these relations.

Online Editor - TABLE 2 (to be formatted) 
TABLE 2

Radial distance between the two spiral ligaments in radial-vertical section (chart 1, figure 3)




AVERAGE DISTANCE BETWEEN TURNS IN M


AGE


TTTT'nWP





I-II


III-IV


I-II plus III-IV


days


grams




mean


1


5


1410


925


1168


3


8


1560


1025


1S93


6


11


1650


1175


1413


9


10


1635


1225


1430


12


13


1640


1233


1437


15


13


1655


1235


1445


20


29


1645


1250


1448


25


36


1620


1250


1435


50


59


1615


1253


1434


100


112


1663


1270


1467


150


183


1618


1290


1454


257


137


1655


1275


1465


366


181


1635


1285


1460


546


255


1680


1265


1473


Ratios 1 12 days 1 1.2


1 20 " 1.2


1 546 " 1.3


In table 3 are given the average ratios between two radial distances between I-II and III-IV at four ages. Here we can also see a rapid increase in the ratio from one to eight days of age, while afterwards the ratios rise very gradually. The data in table 2 show that at nine days the mean diameter of the bony cochlea as thus measured is approximately 97 per cent of the value at maturity. The cochlea thus attains nearly its full size at an early age. Chart 1 illustrates this point.


Online Editor - TABLE 3 (to be formatted) 
TABLE 3 Condensed

Ratios of distances between the two spiral ligaments along 1-1 (turns I-II) and along 2-2 (turns III-IV), figure 3


AGE


BODY WEIGHT


Ratios between the two distances turns I-II and III-IV


days


grams



1


5


. 1:0.66


8


11


0.72


18


21


0.75


213


138


0.77


Chart 1 The radial distance between the spiral ligaments, turns I-II and III-IV, table 2, figure 3 (/-/) and (-).

Radial distance at turns I-II.

Radial distance at turns III-IV.

Average radial distance for the two foregoing measurements.

All the charts are plotted on age.

The scale for age changes at 50 days. From to 50 days one interval is equal to five days. From 50 days on, one interval is equal to twenty-five days.

Unless otherwise stated, the measurements recorded in these charts have been made on radial-vertical sections.


B. On the growth of the tympanic wall of the ductus cochlearis

Figures 4 to 12 show the appearance in outline at birth, at three six, nine (not hearing), nine (hearing), twelve, twenty one hundred, and 546 days, respectively. These figures have been drawn from the best corresponding sections at the beginning of the middle turn of the cochlea, figure 3, turn n, which I have selected as the type, as did Retzius.

The fact, demonstrated by many authors, Bottcher ('69), Retzius ('84), and others, that development progresses from the basal to the apical turn is confirmed in the albino rat.

In the albino rat the development of the cochlea, and especially of the ductus cochlearis, is somewhat retarded as compared with man, and the papilla with its elements developed in a great measure during the first ten days after birth.

As we see in figure 4, the ductus cochlearis in the new-born rat is very immature. It is remarkable that the space which lies in adult rats axialward of the papilla spiralis between the membrana tectoria and the limbus spiralis-sulcus spiralis internus (fig. 10) is not yet to be seen. Instead of the space, there is the socalled greater epithelial ridge (der grosse Epithelwulst of Bottcher) figure 4, G. consisting of pseudostratified epithelial cells. These long and narrow cells lie pressed very closely together with their large oval nuclei at various heights. The surface of the prominence sinks slightly in its center, and at the outer end of the prominence more rapidly, where it passes over into the socalled lesser epithelial ridge fig. 4, L. (der kleine Epithelwulst) at an obtuse angle.

The latter is, of course, a relatively small prominence, making up the greater part of the papilla spiralis. The pillar cells of Corti lie with their upper ends at the most inner part of the surface of the lesser ridge just in the angle with the greater ridge. They form two entirely separate rows of cells, the inner and the outer, but so close together that we cannot detect any space between them. Only the protoplasm of the inner pillar cell is more transparent above the nucleus, and on the inward side there is a thin rod passing from the upper end to the lower part near the base. This transparent area is not the locus of the future tunnel of Corti, but marks the protoplasmic change into the pillar, as the transparent substance condenses into the rod. We can see this change beginning in the basal turn before it appears in the apical turn of the cochlea. The inner and outer cells make a triangle with a narrow base, which clings to the membranea basilaris; they turn somewhat outward. 1

A large oval nucleus lies in the basal part of each cell; that of the inner pillar cell is very large, about twice as large as that of the outer, and with its long axis in a radial direction. As figure 4 shows, the inner corner of the inner pillar cell does not yet reach to the habenula perforata.

The hair cells, which in the albino rat are in four rows through all the turns, are separated by the pillar cells into two groups, the inner containing one and the outer three rows of cells. They are comparatively well developed at birth (fig. 4). The inner hair cell belongs to the greater ridge, as Kolliker ('67), Gottstein (72), Retzius ('84), Held ('09), and others have already affirmed, and contrary to the assertaion of Bottcher ('69) and others.

It is situated in the most outer part of the declivity of the greater ridge and slants away from the axis with its round lower end at about half the height of the greater thickening. It has a large round nucleus in the base and the small hairlet at the top. This hair cell is nearly twice as large as the outer hair cells. The three outer hair cells reach down to the middle of the lesser ridge, not through it, having no process at their basal end. They end with their upper parts at the surface of the prominence. They stand not straight, but turn with their long axis very slightly inward, i.e., the in direction opposite to the long axis of the inner hair cells. They are cylindrical in form with a round nucleus at their base and small hairlet on the top.

Below the outer hair cells stand the three rows of Deiters' cells, which have large oval nuclei. These rest with their wide bases on the basilar membrane and their pointed ends reach to the surface of the epithelium. They are retarded in development, and at birth their cell bodies are short and undeveloped, so that they hardly suggest the adult cells.


  • 1 In the following description of the cochlea, 'outward' means away from the axis 'inward' towards the axis.



Hensen's supporting cells (fig. 10, at maturity) are as yet undeveloped and nearly uniform in height, their nuclei being at nearly the same level.

Outward from the Hensen's cells the height of the epithelial cells at maturity rapidly diminishes and passes over to the cylindrical cells of sulcus spiralis externus. At birth no such distinction is present. Through all the turns the surface of the lesser epithelial ridge remains about parallel to the plane of the membrana basilaris.

The membrana basilaris, which stretches from the labium tympanicum outward to the crista basilaris of the ligamentum spirale, consists of two layers, an upper, membrana basilaris propria, and an under, tympanic investing layer (tympanale Belegschicht : Retzius). The former, of course, is divided into two portions, an inner, zona arcuata (Deiters) and an outer, zona pectinata (Todd-Bowman). While the zona arcuata is thin from the beginning of life, the zona pectinata thickens at its central part where it contains cells with oblong nuclei. On passing to the spiral ligament it again becomes thin. In the young, the under layer is not so regular in structure as in the adult. The *cells close to the basilaris propria are arranged vertically.


Figs. 4 to 12 Showing the increase in size and morphological changes in each part of the tympanic wall of ductus cochlearis of the cochlea during growth, in the radial vertical section albino rat. All the figures have been uniformly enlarged.

Fig. 4 One day. C, greater epithelial ridge; L, lesser epithelial ridge.

Fig. 5 Three days.

Fig. 6 Six days.

Figs. 7 to 8 Showing the differences in size and morphological changes in the tympanic wall of ductus cochlearis between a nine-day-old rat which can already hear (fig. 8) and one that cannot (fig. 7)

Fig. 9 Twelve days.

Fig. 10 Twenty days. In figure 10 we have drawn all the elements of the organ.

ABBREVIATIONS

M.T., membraua tectoria a. Corti O.P., outer pillar

L.V., labium vestibulare of crista B.C., basal cells

spiralis D.C., Deiters' cells

S.S.I., sulcus spiralis interims Bo.C., Boettcher's cells

S.I.C., cells of sulcus spiralis interims L.S., ligamentum spirale

I.S., inner supporting cells N.F., myelinated fibers of ramus I.H., inner hair cells acustici

O.H., outer hair cells R.F., radial fibers of ramus basilaris H.S., Hensen's supporting cells acustici in the tunnel of Corti

S.E.C., cells of sulcus spiralis externus T., tunnel of Corti

M.B., membrana basilaris B., blood vessels

I. P., inner pillar 0., bone

Fig. 1 1 One hundred days.

Fig. 12 546 days.


On the contrary the cells below them, which vanish in great part with age, have an irregular arrangement; those near the endothelial cells of scala tympani having a more radial arrangement. Therefore, this layer is thick, several times the thickness of the basilaris propria, and the thickness increases towards the upper turns. The vas spirale is strikingly large at this stage and lies just under the outer pillar and the Dieters' cells.

The membrana tectoria, beginning at the inner angle of the ductus cochlearis, where Reissner's membrane rises, covers the epithelium of the limbus laminae spiralis and the greater epithelial ridge, lying close to their surfaces. At the inner part it is thin, but thickens where the greater ridge begins, and at the outer part again becomes thin. In the basal turn there is seen as a very thin strand reaching to Hensen's prominence, but in the apical turn it reaches hardly to the inner hair cell. Although it gives rise to several thread-like processes going to the surface of the papilla, these do not seem to connect with the hairs of the hair cells, but with the terminal plates of the Dieters' cells.

When we divide the tympanic wall of the ductus cochlearis at the boundary between the greater and lesser epithelial ridges, we observe that the inner portion from the inner angle to the outer end of the greater ridge is far larger than the outer portion, which, however, is the more important for hearing. This relation becomes more evident as we pass from the base to the apex. Moreover, the total radial length of the tympanic wall diminishes at this stage towards the apex, though it is larger in the beginning of the middle turn than in the middle of the basal turn. As will be shown later, these relations are entirely reversed in the adult cochlea. This fact indicates that the cochlea at this stage is very immature.

In the three-day-old rat the cochlea is much better developed (fig. 5). The radial breadth of the typmanic wall of the ductus cochlearis becomes greater in all the turns, especially in the upper turn; therefore the differences between the radial breadths in each successive turn are smaller than at the earlier stage. There is some change as we pass towards the apex in the relation of the inner and outer portion of the tympanic wall. At the basal turn and the beginning of the middle turn the radial breadth of the outer portion increases greatly, but diminishes again towards the apex. Although the radial breadth of the inner portion increases through all the turns, the proportion of this increase becomes greater towards the apex. As the inner portion is composed of the greater epithelial ridge and of the limbus laminae spiralis, and as the breadth of the latter diminishes towards the apex, the increase of the radial breadth of the inner portion is due to changes in the greater epithelial ridge.

The heights of the greater epithelial ridge, however, diminishes through the successive turns, becoming less and less from base to apex. Thus in the cochlea at this age it has a small radial breadth and vertical height in the basal turn and a larger radial breadth and height in the upper turns.

In all the turns the inner hair cell is inclined outwards and lies with its surface forming the outermost part of the greater ridge. The obtuse angle which it helps to make (fig. 5) as a boundary between the greater and lesser ridge in upper turns, vanishes in the basal turn where there is no sharp boundary between the two ridges.

The pillar cells of Corti develop more and more during this early stage; the radial breadth of their base increases, but as yet there is no space between them. They incline much more outwards than in the earlier stage. The protoplasmic change in the rod progresses, especially in the basal turn, and the head plate of the cell can be seen distinctly.


The outer hair cells become higher and wider; they are slightly inclined inward in the upper turn. On passing towards the basal turn the inclination inward increases, and in the basal turn it is most oblique, almost at 45, to the plane of the basilar membrane. In figure 4 the inclination of these cells is only slight.

Deiters' and Hensen's cells are not well developed; the conditions are as in the former stage.

The plane of the surface of the lesser epithelial ridge is intimately related to the development of the outer hair cells and Deiters' cells, and as the latter are in an undeveloped condition, it runs nearly parallel to the plane of the membrana basilaris, sometimes dipping outward.

The membrana basilaris seems to be much longer; its composition is about the same as that in the one-day rat, only the thickness is somewhat decreased, owing to the reduction of the rows of cells in the tympanic layer.

The membrana tectoria grows in breadth and thickness, covering very closely the inner portion of the tympanic wall and connects outwards with Deiters' and Hensen's cells by slender fibrous processes the so-called outer marginal zone. The hairs of the cells stand between these processes, but have no connection with them.

The vas spirale does not suffer reduction.

At six days (fig. 6) the development of the cochlea has proceeded futher. The radial breadth of the tympanic wall has increased. Thus we find the tympanic wall, especially its inner portion, increasing towards the apex, chiefly owing to the augmentation of the radial breadth of the greater ridge. In this a remarkable change is to be seen. In the basal turn the long slender cells disappear in the inner part of the greater ridge, and instead of them there are found cylindrical cells with oval nuclei near their bases.

The height of these cells increases gradually to the level of the surface of the inner hah- cell; their upper surface is here in contact with the membrana tectoria. Thus a space appears between the cylindrical epithelium and the membrane the sulcus spiralis interims which is deep and wide in the basal turn, becomes gradually shallow and narrow as we pass upward, and in the middle part of the middle turn is to be seen as a small and flat space. In the apical turn it is not yet present. The inner side of this space is made by the labium vestibulare of the limbus laminae spiralis.

As a result of this change in the greater ridge, the obtuse angle between the greater and lesser ridge vanishes entirely, and the two surfaces come to lie in the same place. The inner hair cell becomes larger and inclines less outward.

It is to be noted that the inner hair cell is supported on both sides by long slender cells. These have been variously described by several authors, but first Hans Held ('02) and afterwards Kolmer ('07) have considered them as supporting cells, reaching from the surface of the hair cell to the plane of the basilar membrane. Held has termed the cell which lies outward the ' Phalangenzelle. '

I have paid some attention to this cell and the changes in it. It is long and slender and stands between the inner hair cell and the inner pillar cell, with the upper end reaching to the surface, and is attached at its base to the inner corner of the inner pillar. The oblong oval nucleus lies in its basal portion. On the inner side of the inner hair cell there is a group of two to three cells of the same kind. These cells, termed ' Grenzzellen ' by Held, stand near the habenula perforata, reach to the height of epithelium, and have their bases in intimate relation to the former.

These are not neuro-epithelial cells nor in intimate relation with the nerve fibers, but similar to the Deiters' cells which support the outer hair cells.

The developing pillar cells become progressively wider at their bases. The inner pillar cell sends a long foot towards the habenula perforata and in the basal turn it sometines reaches to it. The outer pillar cell increases its length very rapidly and extends its foot outward on the basilar membrane. Thus in the basal turn the triangle made by the inner and outer pillar cells and having a short base, in the upper turns changes to an equilateral triangle and stands upright on the basilar membrane. In the apical turn the inner pillar cell is not yet so long as in the lower, turns and is still inclined outwards. The head plates and pillars are fairly prominent, but there is as yet no space between them.

The outer hair cells have grown and are inclined inward. Deiters' and Hensen's cells have not yet begun to develop, as have the other elements of the organ of Corti just described.

In the membrana basilaris we see the reduction of cells in the tympanic covering layer. The vas spirale shows more or less reduction. The membrana tectoria increases its radial breadth following the associated structures. The so-called marginal zone connects with Hensen's cells and the lamina reticularis by fibrous processes.

Among five nine-day-old rats, as shown later, one responded to the tests for hearing. As the majority of them gave no reaction, the cochlea of the latter, non-hearing rat, may be taken as the type for this age. The differences between the cochlea of the hearing and non-hearing rats will be mentioned later.

In rats of this age (fig. 7.) the cochlea is still further advanced. The sulcus spiralis internus appears through all the coils, and is deepest and broadest in the basal turn, diminishing in depth or gradually toward the apex. The cells covering the space are low and cuboid in the lower turns, but in the apical turn they are yet relatively high, cylindrical cells.

These cells probably have their origin from the long slender cells of the greater epithelial ridge, as Bottcher ('69) and others maintain, although Gottstein (72) and some others think that they come by the outward migration of the epithelium of the limbus spiralis, and Retzius ('84) regards this latter view as the more probable.

The inner and outer hair cells become large and approach their mature form. The supporting cells of the inner hair cell are very evident.

The pillar cells develop more and more, their radial breadth increases and the pillars and headplates also become distinct. Sometimes we see a small space between the inner and outer pillar cells in the lower turn, but not in the upper. Nuel 's space is not yet to be seen. Deiters' cells become longer, somewhat in the processus phalangeus but chiefly in the cell body, and the nuclei move upward. Hensen's cells also increase in height slightly.

While the membrana tectoria lies close to the surface of the outer part of the greater ridge in the upper turns of the cochlea, there arises a small space between them, which is continuous with the sulcus spiralis internus. The outer marginal zone of the membrane is still connected with Hensen's supporting cells and the lamina reticularis. The vas spirale remains as a large vessel. This is the condition of the nine-day cochlea in a rat which does not hear.

Although the detailed description of the cochlea of the nineday rat which can hear will be deferred for a time, yet to complete the series of growth changes, figure 8, representing the cochlea in such a rat, is inserted here.

In the next stage, twelve days old (fig. 9), the development of the tympanic wall is much advanced. The cells lining the sulcus spiralis internus and the-inner supporting cells have nearly their mature form and arrangement in the basal and middle turns; only in the apical turn many and slender cells remain close to the inner hair cell.

The outer pillar cell shows a remarkable increase in length so that it is twice as long as in the former stage, while the growth of the inner pillar is much less marked.

Therefore the outer pillar is much longer than the inner through all the turns. From this change in the pillar cells it results that the nearly equilateral triangle formed by them becomes unequal and its summit is shifted inward. In all the turns we can see the tunnel of Corti and also the space of Nuel. The hair cells develop further and their previous inclinations are increased.

Deiters' cells show a very rapid development, especially in the cell body, which increases many times, the nucleus moving upwards. The inclination of these cells follows that of the outer hair cells.


Hensen's supporting cells are also fully developed. Through the development of Deiters' and Hensen's cells a change is effected in the course of the lamina reticularis. It runs no longer parallel to the plane of the membrana basilaris, but dips inward.

Though the membrana basilaris remains nearly stationary in its breadth, the thickness of the tympanic covering layer is reduced and the longitudinal nuclei in the zona pectinata diminish in number.

The membrana tectoria reaches in the basal turn to the outermost row of the outer hair cells, but the apical turn only to the second row. The so-called 'outer marginal zone' connects with the terminal frame (Schlussrahmen) of the lamina reticularis.

In the next stage, the twenty-day-old rat (fig. 10), the papilla spiralis and the tissues about it are developed almost completely; therefore, the structural relations of the cochlea accord nearly with those of the adult cochlea, as generally recognized in histology.

It is to be noted here that in the basal turn, Bottcher's cells are to be seen in sulcus spiralis externus* as a cell group situated on the outer part of the vestibular surface of the membrana basilaris. This cell group consists of several granular compact and sharply bounded cells entirely covered by high swollen cells on all sides. That this cell group belongs to the epithelium of the sulcus spiralis externus can be easily demonstrated. While the cells in this group show no particular changes in structure, the neighboring cells diminish in their height and size towards the apex, and finally become similar to the former. After twenty days of age the general features of the cochlea are those of the adult and do not require general description. The finer differences will be discussed in subsequent chapters.

Figure 11 shows the relations at 100 days and figure 12 at 546 days.

1. Membrana tectoria

As stated above, this membrane is divided into two zones, an outer and inner, using the outer edge of the labium vestibulare as the point of division (fig. 1, 7-7'). Each zone was again divided into two equal parts at 6-6'and8-8'. Thus the sum of the breadths of the two outer parts represents in each instance the breadth of the outer zone, and the sum of the two inner parts that of the inner zone, while the sum of all four parts gives the total radial breadth. For the purpose of the exact measurement of the growth of the membrane, I have, as noted above, projected the sections at 100 diameters and made the determinations on the outlines thus obtained.

In table 4 (charts 2 and 3) are given the values for the total average breadth, as well as for that of each zone, and also the thickness of the membrane, from 1 to 546 days of age. At the bottom of each column are given the ratios of the breadth at 1 to 546, 12 to 546, and 20 to 546 days. While the ratio between 1 and 546 days is 1.7, those from 12 to 546 days and 20 to 546 days diminish to about 1:1.0, that is the membrane at twelve days has attained about its full breadth, and there is only a very gradual increase in its breadth with advancing age. After twelve days similar ratios are found for the separate zones as well.

From 1 to 546 days the ratios for the two zones differ considerably; that for the second zone is 1:1.2 and that for the first is 1:3.6. This is due to the fact that in the cochlea at birth the development of the labium vestibulare is incomplete, even in the basal turn, while at the apex we can very often hardly see the invasion of the mesenchymal tissue in the inner part of the greater epithelial ridge.

At every stage the outer zone is broader than the inner; the ratio between them at birth is 1:3.8. This diminishes to 1:1.25 at twelve days, after which age it remains practically constant. Owing to the form of the membrana tectoria and to its great sensitiveness to the method of preparation, it is difficult to obtain good values for its thickness.

Generally speaking, the membrane is thickest about midway between the outer edge of the labium vestibulare and the inner boundary of the inner hair cell, and it was here the measurements given in table 4 were made. As shown in this table, the thickness increases rather rapidly from birth to twenty days, but after that period remains approximately constant.


As we know, the radial breadth of the membrane increases gradually from the basal to the apical turn. Table 5 (charts 4, 5, and 6) shows how the breadth of the total and of each part of the membrane changes in successive turns from base to apex according to age. At birth it is broadest in the beginning of the middle turn (turn II) decreasing gradually towards the apex. From three to twenty days the greatest breadth is usually found

TABLE 4

Average radial breadth of the membrana tectoria and its thickness in radial-vertical section. Averages of all four turns (charts 2 and 8)


AGE


BODT WEIGHT


BODY LENGTH


Outer zone between free end of membrane and labium


Inner zone labium vestibulare and insertion of membrane


Total length of membrane


Ratios inner and outer zone


Thickness membrane


days


grams


mm.


M


M


M



M


1


5


48


140


37


177


1 3.78


12


3


8


56


134


94


228


. 1.43


32


6


11


63


154


105


259


1.44


32


9


10


58


158


123


281


1.28


27


12


13


60


157


126


283


1.25


25


15


13


75


160


124


284


1.29


28


20


29


95


162


129


291


1.26


38


25


36


104


162


128


290


1.27


34


50


59


125


162


131


293


1.24


35


100


112


159


162


132


294


1.23


36


150


183


190


161


131


292


1.23


32


257


137


175


163


129


292


1.26


38


366


181


191


162


131


293


1.24


35


546


255


213


163


132


295


1.23


34


Ratios 1 546 days


1 1.2


1 3.6


1 1.7



1 2.8


t 12 546 "


1.0


1.0


1.0



1.4


20 5 "


1.0


1.0


1.0



0.9


in turn III, but after this in turn IV. At the bottom of each column are given the ratios of the radial breadth in each turn between the several age limits.

These show that after twelve days there is but little change in the radial breadth of the entire membrane in any turn.

On examining the growth in each zone of the membrane through the several turns, we find that after three days the outer zone of the membrane becomes at each age always broader from base to apex.


31


u


200


150


100


50


o


AGE QAYSH i i


O


25


50


5O 10O 2OO 3OO 4OO 50O


Chart 2 The radial breadth of membrana tectoria, table 4, figure 1. Total radial breadth of the membrane.

Radial breadth of outer zone.

  • - Radial breadth of inner zone.


25 50 50 10O 2OO 3OO 4OO 5OO

Chart 3 The thickness of membrana tectoria, table 4.


32


ANATOMICAL AND PHYSIOLOGICAL STUDIES ON


ta o

i < -S


a

2 S BS


.


n w

it


T^cOTtiCO-'^ -HOOOOOO


o; (


o;^ ^-^


(N 00


OOOOOOOO


co o !o


rH O


rH O


>> ^

c3


1 O I


rH'HCScouv.S "3:uj W i i ' co


20-546


GBOWTH OF THE INNER EAR OF ALBINO RAT


33


The values at birth are relatively greater than those at three days, as noted above, due to the undevelopment of the labium vestibulare. The inner zone grows in a like manner in breadth, but not so rapidly as the outer zone, and hence its relative breadth diminishes gradually from base to apex.

Table 6 shows these relations. While the ratios in the inner zone decreases from base to apex, those in the outer zone increase. Thus the ratios in the inner and outer zones according to the turns go in opposite directions. As stated above, the radial breadth is generally larger in the outer zone, but this relation is, in general, reversed in turn I, table 5.

TABLE 6 Condensed Ratios of the radial breadth of each zone of the membrana tectoria




Ratios according to turns of the cochlea






Ratios between inner and



BOOT


INNER CONE


OUTER ZONE


outer zone


AGE


__ fjfi**T







Turns


Turns


Turns




I-II


I-III


I-IV


I-II


I-II I


I-IV


I


II


in


IV


days


grams












1


5


1:0.8


1:0.5


1:0.0


1:1.2


1:1.3


1:1.4


1:1.8


1:2.8


1:4.3


1:0.0


8


11


0.9


0.9


0.8


1.4


1.8


1.9


0.8


1.2


1.6


2.0


18


21


0.9


0.9


0.8


1.4


1.8


2.0


0.8


1.1


1.5


1.9


203


160


0.9


0.9


0.8


1.4


1.7


2.0


0.8


1.1


1.5


1.8


In turn I the average ratios are, after eight days, smaller than 1.0; therefore, the inner zone is wider than the outer in turn I. It increases in all ages from turn II toward the apex.

In table 7 are given the ratios between each turn of the cochlea. The ratios after nine days of age are practically constant according to age, but those between turns I and II are always smaller than the others; the ratios for the two latter being alike. The ratio at one day is, however, an exception, as stated already.

As the measurements show, the membrana tectoria is at birth relatively undeveloped; it is thin and immature. After birth it increases rapidly during the first nine days, a statement which applies generally to the postnatal growth of the organs of the albino rat. Thus we get a ratio of the radial breadth 1 :1 .7 between 1 and 546 days, but after twelve days the ratios remain practically 1:1.0. (Table 4.)


ANATOMICAL AND PHYSIOLOGICAL STUDIES ON


It is not my purpose to describe the fetal development of the membrana tectoria, but it is worth while to consider briefly the zones which compose the membrane; in other words, the parts of the tympanic wall from which it originated. There are chiefly

TABLE 7

Ratios of the radial breadth of the membrana tectoria according to the turns of the

cochlea


AGE


BODY WEIGHT


Ratios according to turn of the cochlea


I-II


I-II I


I-IV


days


gms.





1


5


1 1.0


1 1.0


1 :0.9


3


8


1.2


1.2


1.2


6


11


1.2


1.4


1.3


9


10


1.1


1.3


1.3


12


13


1.1


1.3


1.3


15


13


1.1


1.3


1.3


20


29


1.1


1.3


1.3


25


36


1.1


1.3


1.4


50


59


1.1


1.3


1.3


100


112


1.1


1.3


1.4


150


183


1.1


1.3


1.3


257


137


1.1


1.3


1.3


366


181


1.1


1.3


1.3


546


255


1.1


1.3


1.3


Chart 4 The total radial breadth of membrana tectoria arranged according to the turns of the cochlea, table 5.

About middle part of the basal turn (I).

About the beginning of the middle turn (II).

About the middle part of the middle turn (III).

About the beginning of the apical turn (IV). 2

Chart 5 The radial breadth of the inner zone of the membrana tectoria,

according to the turns of the cochlea, table 5.

Chart 6 The radial breadth of the outer zone of the membrana tectoria,

according to the turns of the cochlea, table 5.

  • In most cases when the values which have been determined are analyzed

according to the turns of the cochlea, it is found that they increase with later growth from the basal (I) to the apical (IV) turn and in the order just given in chart 4. Owing to this uniformity of behavior, some thirteen charts showing the several values according to turn have been omitted, since the graph given by the average value is sufficiently informing in each instance.

In the case of those charts which have been retained, and in which the measurements are according to the turns of the cochlea, the respective turns I-IV are recorded by characteristic lines similar to those used for them in chart 4, and in these cases the further designations of the turns are omitted.


350


300


I


ISO


G.E DAYSH




25 5O


50 1OO 2OO 30O 400 500

Chart 4


150


1OO


50




AGE


25 50 50 1OO 200 300 4OO 500

Charts


180


100


DAYS


25 50 5Q 1OO 2OO 3OO 4OO 5OO

Chart 6


36

two views about this. While a few authors, Kolliker ('67), Hensen ('63), and recently Hardesty ('08, '15), and others hold that only the greater epithelial ridge takes part in the formation of the membrane, most investigators (for example, Bottcher, '69; Retzius, '84; Rickenbacher, '01; Held, '09; Van der Stricht, '18) consider that it originates from both the greater and lesser epithelial ridge. My figure 5, supports the latter view; that is, while the main part is developed from the greater ridge, the outer narrow marginal part is secreted from the lesser ridge.

The figure in Quain's Anatomy by Schafer ('09) (vol. 3, part 2, p. 332, llth ed.,) is from the earlier paper of Hardesty and shows the membrane in the pig as arising from the greater epithelial ridge only.

Hardesty has corrected this figure in his paper published in 1915. Thus in the very early stage after birth in these forms we have three zones, an inner, an outer, and a marginal zone. With age, however, this marginal zone becomes, as Held ('09) and others agree, gradually smaller and smaller, and finally it is difficult to differentiate it from the outer zone. Thus for convenience in measurements I have treated the membrane as consisting of two zones only.

Comparing the breadth of the inner and outer zones, it is evident that the outer is always the broader. The ratio is (table 4) at birth 1 : 3.78, at three days 1 : 1.43, and then gradually diminishes to 1:1.23 with age.

Now if we examine the ratios of the total breadth of the membrane according to the turns of the cochlea, we find after six days that the ratio generally increases from base to apex, and that these ratios remain nearly constant after nine days of age, as shown in table 7.

Thus the ratio between turns I and II is 1:1.1; between turns I and III, 1:1.3; between turns I and IV, 1:1.3. The breadth of the membrane increases, -therefore, in the albino rat gradually from the base to the middle part of the middle turn; from this point it does not increase to the apex.

Since the breadth at the tip of the apex diminishes greatly, as is generally recognized, Hardesty ('08) found in the pig the following ratios (table 8):


GROWTH OF THE INNER EAR OF ALBINO RAT


37


Comparing these ratios obtained by Hardesty in the pig with mine, there appear to be large differences between them. The reason for these I will discuss later.

When we consider the breadth in each part of the membrane according to the turn, we find that the increase of the breadth of the membrane in each turn is due to the development of the outer zone. The inner zone, which is adherent to the labium vestibulare, does not increase in the rat as Hardesty ('08/15) found to be the case for the pig, but on the contrary decreases from base to apex a relation found by Retzius ('84) in the rabbit, cat, and man and confirmed by Rickenbacker ('01) in the guineapig. On the contrary, the outer zone increases in breadth from

TABLE 8 Ratios of the breadth of the membrana tectoria according to turn of cochlea (Hardesty)


Kind of animal


Preparation method


Ratios between breadth in 7 and 5 half turn


Ratios between 7 and 3 half turn


Ratios between 7 and 1 half turn


Pigs two weeks of age


Membrane teased out Membrane


1 : 1.4


1 :1.7


1 :2.5



teased out


1 :1.8


1 :2.5


1 :2.7


Adult


Membrane in






section


1 : 1.6


1 :2.1


1 :1.8


base to apex, and in each stage the ratios between the successive turns are nearly the same. These ratios between successive turns, however, show rather large differences according to the different authors.

My results (table 5) show that the outer zone in the albino rat is nearly two times wider at the apex than at the base. This agrees with what von Ebner ('02) finds in the human cochlea.

When we consider the thickness of the membrane, we find it thin at birth, but at three days (table 4) it increases rapidly and reaches almost its greatest thickness. This increase in thickness arises through the apposition of new layers to the under surface, as Hasse (73) and others have noted, but very large differences appear between the figures given by various authors.


38 ANATOMICAL AND PHYSIOLOGICAL STUDIES ON

Kolliker ('67) finds the membrane 45 n thick in the ox. In the guinea-pig it is 15 ^ in the thickest place, according to Schwalbe ('87). Middendorp ('67) gets in mammals generally a very thin membrane, about 1 n thick. Retzius ('84) states that in the thickest part in the rabbit it measures 27 [x, in the cat 32 to 50 |x, and in man 24 to 25 [x. Hardesty finds in the young pig an average thickness of the teased membrane of 50 [x and in an adult hog 119.3 (x. I get 35 (x as an average in the adult albino rat after twenty days of age, varying from 32 to 38 [x. My result is therefore closest to that for the cat as obtained by Retzius. These results are plainly influenced b.y the dissimilar technical methods used by the several investigators.

About the outermost end of the membrane there are still two different views. One view is that the outer end of the membrane projects beyond Hensen's prominence; Kolmer ('07; pig, calf goat and horse); Hardesty ('15; pig, hog) Shambaugh ('10; pig). Others assert that the membrane terminates with its outer edge at the outer boundary of the outermost series of the outer hair cells. My preparations show that in the rat the outer end of the membrane does not reach Hensen's prominence.

Possibly this difference is due to the technique of preparation. In the figures drawn by many authors we can recognize many artifacts and postmortem changes in the cochlea. Even in the figures of Kolmer ('07) we see these changes, although he injected the fixing solution through the carotid artery. Held ('09) says in his criticism of Hardesty 's figures that " figures 6 and 7 wie schon Hardesty selbst vermutet hat, sicherlich auf einer Verquellung beruhen "

I myself never observed such a gigantic membrane as Hardesty ('08, '15), Shambaugh ('10), and others show in the cochlea of the pig. On the other hand, I cannot absolutely deny that there may have been shrinkage in the cochleas prepared by my methods, though I see no evidence of it.

From our present knowledge, however, the method of vital fixing is considered the best available, as already maintained by Siebenmann and Yoshii ('08), Metzner and Yoshii ('09), Nager and Yoshii ('10), Wittmaack and Laurowitsch ('12), and others.

By using this vital-fixation method we get perfect sections which can be used to solve the problem of the shifting of the organ of Corti an event which I will discuss later.

2. Membrana basilaris

The membrana basilaris of the cochlea stretches between the limbus laminae spiralis and the ligamentum spirale. The acoustic terminal apparatus is situated on it and according to the dominant Helmholtz-Hensen theory, this membrane is to be considered as very important in tone perception. The row of the fine holes, foramina nervina, is generally designated as the inner boundary of this membrane. Strictly speaking, however, the beginning of the membrane is at the outer edge of the labium tympanicum, which sharpens at first beyond the foramina nervina and passes over to the substance of the membrana basilaris. Practically it is almost impossible to decide exactly the point of transition. Thus I have used in the measurement of the membrane the foramina of the habenula perforata as an inner limiting line following in this Retzius, ('84) Schwalbe ('87), and others. Here it is to be mentioned that the organ of Corti lies with its inner portion not only upon the inner part of the membrane, but extends to the foramina nervina also.

The membrana basilaris is usually divided into two portions; the inner, termed the zona arcuata, and the outer, the zona pectinata. The former stretches from the habenula perforata across the base of the tunnel of Corti to the outer edge of the foot of the outer rods of Corti ; the latter extends from this point to the ligamentum spirale (fig. 2), 5= inner zone, 10= outer zone.

In table 9 (chart 7) are given the values for the total radial breadth of the membrane, that of each zone, and the ratios between them. At the bottom of each column are given the ratios at 1 to 546, 12 to 546, and 20 to 546 days of age. In the total radial breadth of the membrane, as the table shows, there are large differences on age from birth to nine days. Between 1 day and three days the increase is 30 |x and between three days and six days, 28 [A. After nine days the breadth increases more slowly but continuously to old age.

In the growth of both zones we see about the same relation. These increase rapidly from birth till nine (or twelve) days and after that very slowly. These relations are shown clearly in the ratios at 1 to 546, 12 to 546, and 20 to 546 days. While after twelve days the ratios in total breadth and in each zone are the same, 1:1.1, that for 1 to 546 days is smaller for the outer zone than it is for the inner zone, thus the inner zone increases considerably after birth, while the outer zone does not grow, as some authors have imagined, as much as the inner zone. I will discuss this point later.

Online Editor - TABLE 9 (to be formatted) 
TABLE 9

Radial breadth of Ihe membrana basilaris measured between the foramina nervina and ligamentum spirale in radial sections on age (chart 7, fig. 2}


AGE


BODY WEIGHT


INNER ZONE

(Zona arcuata)


OUTER ZONE

(Zona pectinata)


Total radial breadth of the membrane


Ratios between the radial breadth of the inner and outer zone


days


grams


P


M


M


M


1


5


49


75


124


1 1.5


3


8


63


91


154


1.5


6


11


77


105


182


1.4


9 1


10


79


111


190


1.4


12


13


- 88


100


188


1.1


15


13


87


102


189


1.2


20


29


86


106


192


1.2


. 25


36


87


108


195


1.2


50


59


88


107


195


1.2


100


112


92


106


Id8


1.2


150


183


92


107


199


1.2


257


137


92


107


199


1.2


366


181


93


111


204


1.2


546


255


94


113


207


1.2


Ratios 1 546 days


1 1.9


1 1.5


1 1.7



12546 "


1.1


1.1


1.1



20546 "


1.1


1.1


1.1



1 A rat of nine days which could hear, gave the following:


Right side 11


94


103


197




91


104


195




93


104


196


1 : 1.1


Comparing the growths of the radial breadth of the inner and outer zones, we find that the inner zone is relatively narrow at nine days; thus the ratios between them are 1:1. 4; after that period the inner zone increases rapidly, and even at twelve days the ratio becomes 1:1.1, which is almost the same as in the adult, 1:1.2.


In table 10 the radial breadths of the whole membrane and of its zones are arranged accordingly to the turns of the cochlea on age. At the bottom of each column are given the ratios from 1 to 546, 12 to 546, and 20 to 546 days. We see at first that the total radial breadth at one day is largest in the basal turn; at three days it becomes larger on passing from the basal toward the II and III turns, but in turn IV it is again small.


Chart 7 The radial breadth of the membrana basilaris, table 9, figure 2, distance 11.

Total radial breadth of the membrane.

Radial breadth of the zona pectinata.

Radial breadth of the zona arcuata.

After six days it is a well-known fact that the radial breadth of the membrana basilaris is narrowest in the basal, and widest in the apical turn (not the tip of the apex, but the beginning of the apical turn). These differences are not always the same between all the turns; those between I and II, and II and III are marked; those between III and IV are small. The ratios at 1 to 546 days show those for the upper turn to be largest, while from 12 to 546, and 20 to 546 days the ratios in all turns are about 1:1.1.



In the zona arcuata (inner zone) the same relation is to be seen in each turn; therefore, in the early period the breadth is less in turn IV than in the other turns. Very soon, however, the value in turn IV becomes the largest and diminishes toward the base. The rate of the growth of this zone, from 1 to 546 days, is also smallest in turn I, and largest in turns III or IV; the ratios being in the first 1:1.6, and in the last 1:2.1.

In the zona pectinata (outer zone) we see also similar relations.


Online Editor - TABLE 11 (to be formatted) 
TABLE 11

Ratios of the radial breadth of the membrana basilaris according to the turns of the

cochlea on age


AGE


BOOT WEIGHT


Ratios between turns


I-II


I-III


I-IV


days


gms.





1


5


1


1.0


1


1.0


1


1.0


3


8



1.0



1.0



1.0


6


11



1.1



1.2



1.2


9


10



1.1



1.2



1.1


12


13



1.2



1.3



1.3


15


13



1.1



1.3



1.3


20


29



1.1



1.2



1.3


25


36



1.2



1.3



1.3


50


59



1.1



1.3



1.3


100


112



1.1



1.3



1.3


150


183



1.1



1.2



1.3


257


137



1.1



1.2



1.3


366


181



1.1



1.2



1.3


546


255



1.1



1.2



1.3


Only slight differences in the ratios according to age are found.

In table 11 the ratios according to the turns of the cochlea are given. While from one to three days the ratios are the same in each turn, 1:1.0, yet after six days those for turns I to II are smallest, and for I to IV larger, thus showing slight differences between them.

In the literature we find only one description, that by Retzius ('84) touching the growth of the radial breadth of the membrana basilaris according to age. He measured this membrane in the rabbit and cat and got the following values in n (table 12).


Comparing these values with mine obtained for the albino rat, it is to be noted that those of Retzius are generally larger than those for the albino. For example, while I get at birth only 126 (x in the basal turn, Retzius ('84) obtains 180 [x in the rabbit and even 270 [x in the cat. As stated above, the radial breadth increases in the albino rat continuously with age. It is very peculiar to find in the Retzius table that the breadth of the membrane in the cat is decidedly larger at birth than at three and seven days. The average value for the new-born is 315 [x, which is larger than at thirty days, which is 310 [x.

Retzius ' data show the membrane in the rabbit and cat always wider in the apical than in the basal turn at birth and at two days. My results, given in table 10, show the reverse at the ages of one and three days. This is an expression of greater immaturity in the case of the rat.


Online Editor - TABLE 12 (to be formatted) 
TABLE 12

Breadth of membrana basilaris according to turns, p. (From Retzius, '84}


RABBIT


CAT


Age


Basal


Middle


Apical


Basal


Middle


Apical


days








New-born


180


270



270


300


375


2


220


272


280






3





.


200


280



7


270


306



211


258


300


10


255


310


390






11






255


300


330


14


300


360


410






30






240


300


390


In comparisons like the foregoing, several conditions must be kept constantly in view.

So far as absolute values are concerned, it is to be expected that these would be unlike in the different mammals, because the cochleas differ in size. As to the relations between the values at birth and at maturity, it is plain that these cannot be expected to agree unless the cochleas of the animals compared are in the same phase of development at birth. In the foregoing instances it appears that the cat is relatively precocious, as compared with the rabbit, while, as might be expected, because of their closer zoological relationship, the rat and the rabbit are in better agreement, although the rabbit appears to be a trifle more advanced at birth than the rat.

Finally, in the comparison of different series of data, differences due to the lack of homogeneity in the series of animals used and to the various techniques employed can hardly fail to play an important part, and allowance must be made for these disturbing factors.

When we consider the rate of growth, the ratio of a one to a fourteen-day-old rabbit is 1:1.6, according to Retzius; therefore, it has very nearly the value found in the albino. In the cat, however, the ratio between one and thirty days is 1:0.97; therefore, it apparently decreases a bit.


This difference is most readily explained as due to the precocious development in the cat at birth.

On comparing the radial breadth of the membrane obtained from several mammals by various authors, we find the following values (table 13).

Online Editor - TABLE 13 (to be formatted) 

TABLE 13 Breadth of basilar membrane


ANIMAL AUTHOR


TURN IN WHICH MEASUREMENT WAS MADE IN M


Basal


Second


Third


Fourth


Average


Man-New-born



Hensen ('63)


235


413



495


381


Man Mature



Retzius ('84)


210



340


360


303


Calf



Kolmer ('07)


200


280



400


293


Pig



Kolmer ('07)


168


200


256


304


232


Goat


Kolmer ('07)


124


384


432



313


Cat


Bottcher ('69)


90



435



263


Cat







Middendorp ('67)






246-275


The values here given must be read in the light of the various modifying conditions to which reference has just been made.

My average value after twenty days is 199 [i; therefore, it is absolutely the smallest in this series of mammals. The rat is also the smallest species examined.

As shown in the literature quoted, and also in my own results, the membrane increases in its breadth in all the mammals examined from the base toward the apex a relation contrary to that reported by the older authors (Corti, '51, and others). This increase is continuous, but is at first more rapid and afterwards more gradual. The ratios of this increase in the albino rat are given in table 11.

The next question relates to the breadth of each zone of the membrane according to age. So far as I know, there is no such study in the literature, not even in Retzius. In the albino rat, as shown in table 9, each zone increases in breadth with age. The rate of growth, however, is somewhat different, and in the zona arcuata it is greater than in the zona pectinata (1:1.9 and 1 :1.5, respectively), although the absolute value is always greater in the latter.

As noted above, the membrane increases in its radial breadth from the basal to the apical turn. How, and in which portion of the membrane does this increase arise? Henle ('66) first regarded the breadth of the inner (zona arcuata) as approximately constant.

"Nicht nur in den verschiedenen Regionen einer Schnecke, sondern, soviel ich sehe, selbst in den Sshnecken verscheidener Tiere und des Menschen; sie schwankt nur wenig um 0.01 mm." (Eingeweidelehre des Menschen, 1866, S. 793).

In the second edition of his book ('73) he states, however, that in the increase of the breadth according to the turn, both zones seem to take part. Hensen ('63) gets in the zona arcuata of the base of the human cochlea the breadth of 19 ^ and in the apex 85 \L. Middendorp ( '68) gives in the cochlea of the cat a continuous increase of the breadth of the zona arcuata from 94 to 122.5 {A. .""'

More detailed data are given in table 14.

According to all these authors, the breadth of both the inner and outer zones increases from base toward apex and results in the increase of the total radial breadth of the membrane according to turn. My results obtained from the albino rat agree with these data.

3. Radial distance between the habenula perforata and the inner corner of the inner pillar cells at base

The measurements of the radial distance from the habenula perforata to the bases of the inner and outer pillar cells were taken to determine their postnatal growth. As already stated, the cells from which the arch of Corti arises stand at birth nearly vertically and have no space between them (fig. 4). In the adult, however (fig. 10), we see a space, the tunnel of Corti lying between them and changes in the form of the arch occur. To follow these changes it seems at first necessary to study the growth of the pillar cells and of the other elements in the organ of Corti. At the same time we must take into consideration the inward shifting of the organ of Corti, first studied by Hensen. This shift inward of the organ is, according to Hensen, chiefly caused by the wandering of the pillar cells, especially the inner pillar cell. Therefore, it seemed necessary to determine the radial distance of the pillar cells from the habenula perforata at different ages before discussing this interesting problem.


Online Editor - TABLE 14 (to be formatted) 
TABLE 14

Breadth of the inner zone of the membrana baeilaria in n



NUMBER Of TURN



First


Second


Third


Fourth


Cat-adult






Bottcher ('69)


60


105


135



Guinea-pig






Winiwarter (70)


45-52


63-68


71-80


80-83

In table 15 are given the values for the radial distances between the habenula perforata and the inner corner of the inner pillar cell at its base according to age (figs. 4 to 9). As we see, the average value increases till three days of age, then vanishes suddenly, though at six days we have a measurable interval in the upper turns of the cochlea. Comparing these distances according to the turn, they are smallest in turn I and increase toward the apex. In some cases, at six days, we have no interval in the basal turn, but in the higher turns an interval gradually appears and at the apical turn is largest. This table shows, therefore, that the inner corner of the base of the inner pillar cell lies at birth outward from the habenula perforata at an average distance of 22 \L. At three days of age the inner corner moves farther outward with the developing membrana basilaris and the distance increases from the base to the apex. Between three to six days this outward movement not only stops, but reverses its direction, and at six days it often becomes zero in the basal turn. Bottcher ('72) finds in the cat the following values for this interval in \i (table 16).


Online Editor - TABLE 15 (to be formatted) 
TABLE 15 Condensed

Radial distance between the habenula perforata and the inner corner of the inner

pillar at base on age


AGE


BODY WEIGHT


TURNS OF THE COCHLEA M


I


II


ill


IV


Aver.


days


1


5


19


22


22


23


22


3


8


23


28


28


30


27


6


11


In one case 5


In 2 cases 10


14


18


In other 3 cases


In other cases


9


10


12


13


Online Editor - TABLE 16 (to be formatted) 
TABLE 16


CAT EMBRYO 11 CM. LONG


ADULT CAT


I


II


ill


IV


Average


I


II


ill


IV


Average


15


39


30


30


29


3


3


3


3


3


Online Editor - TABLE 17 (to be formatted) 
TABLE 17


RABBIT


CAT


AGE


Basal turn


Middle


Apical


Average


Basal


Middle


Apical


Average


days




New-born


300


300


300


300


5


40


45


30


2


10


12


30


17



3



3


36





7



11




18



Retzius ('84) studied this distance in the rabbit and cat and gets the values given in Table 17.

Comparing the values of these two authors with my own, there are of course some differences. While in the rabbit the interval is large at one day, it is greatly diminished at two days of age. At three days the inner corner of the cell reaches the habenula perforata. In the cat the values are nearer to mine. The fact that the values increase from base toward apex is to be seen here also. This peculiar phenomenon appears, therefore not only in the albino rat, but also in the rabbit and the cat during the earliest stage of postnatal life.

4. The radial distance between the habenula perforata and the outer corner of the inner pillar cell (resp. the inner corner of the outer pillar cell) at base

This measurement is difficult. As we know, the inner and outer pillar cells in the albino are from birth till nine days of age in contact with each other along their whole length, and therefore they do not yet surround the space forming the tunnel of Corti. At about nine days, however, the tunnel appears while the cells remain in contact by their bases. It is almost impossible to determine the line of contact on the basilar membrane in my preparations. To get the radial distance between the habenula perforata and the outer corner of the inner pillar cell I have proceeded therefore as follows:

First, I have measured this distance directly up to nine days of age; after that this distance consists of the sum of the radial basal breadth of the inner pillar (not pillar cell) and the breadth of the inner basal cell on the basilar membrane. Since it is impossible to get the latter value directly in my sections, I considered that half of the radial distance between the outer corner of the inner pillar and the inner corner of the outer pillar would be equivalent to it.

Of course, I do not know whether the value of the sum of these two distances is at all ages, identical with the distance between the habenula perforata and the outer corner of the inner pillar cell at its base. I believe, however, that a systematic study of the growth of this distance will be significant.


In table 18 are given the values for the radial distance between the habenula perforata and the outer corner of the inner pillar at base up to nine days of age. As shown, these values, on the average, increase with age. The increase of this distance means that the base of the inner pillar cell spreads outward more and more.

When we consider this distance according to the coil of the cochlea, it is at birth about the same through all the turns (table 18; at three days it increases up to turn III, and in turn IV the value is the same at the apex as at the base. At six days the value in turn III is also largest, and next largest in turn IV. At nine days of age the same relations are to be seen.

Online Editor - TABLE 18 (to be formatted) 
TABLE 18

Radial distance between the habenula perforata and the outer corner of the inner

pillar at base on age




TURNS OF COCHLEA M


AGE


BODY WEIGHT


I


II


III


VI


Average


days


grams







1


5


40


41


39


39


40


3


8


48


49


50


48


48


6


11


38


45


58


53


49


9


10


44


46


56


53


50


In table 19 (chart 8) are given the values for the radial basal breadth of the inner pillar (not pillar cell) on age. At the bottom of the last column are the ratios from 6 to 546, and 20 to 546 days. As above noted, the rod can be followed at birth from the upper part to near the base of the cell (fig. 4). At three days (fig. 5), its base reaches the basilar membrane as a thin and slender thread, but we cannot measure its basal breadth accurately. During the next few days it increases in radial breadth rapidly, and at six days has the average value of 29 [/. (table 19). After nine days it decreases distinctly till twenty days, after which the value remains nearly constant. These relations are evident in the ratios. While the breadth at six days is about twice that at 546 days, that at twenty days has the same value.

According to the turn of the cochlea, the values from nine to fifteen days become gradually larger on passing from the base toward the apex. After twenty days, however, this relation vanishes, and the values become nearly the same through all


Online Editor - TABLE 19 (to be formatted) 
TABLE 19

Radial basal breadth of the inner pillar on age (chart 8)


day*

1

3

ti

9

12

15

20

25

50

100

150

257

366

546

Ratios 6 20


WEIOHT BODY


TURNS OF THE COCHLEA M


I


II


III


IV


Average


grams







5









8









11


29


31


27


27


29


10


28


28


33


35


31


13


18


19


22


25


21


13


18


18


19


19


19


29


14


15


15


15


15


36


14


15


14


15


15


59


14


14


14


13


14


112


14


14


14


13


14


183


15


15


15


15


15


137


15


15


15


15


15


181


16


17


15


15


16


255


15


14


16


15


15


-546 days






1 :0.5


-546 "


Chart S. The radial basal breadth of the inner pillar (not pillar cell), table 19, figure '2, distance 3.

the turns. In table 20 the ratios of the turns I to II, I to III, and I to IV are given for three age groups (condensed from table


From the data given by Retzius ('84) we get the values in jx of the radial basal breadth of the inner pillar in the rabbit and cat as follows (table 21).

Comparing these values with my own, it is to be noted that Retzius' measurements in the rabbit agree perfectly at the earliest stage with those in the albino rat. Also we find in the rabbit at seven days values homologous with those obtained in the albino rat at fifteen days of age, only in the rat the breadth is absolutely greater. In the cat the values at seven days of age are about the same, or a bit smaller, than those in the albino rat. Here again the rabbit is a trifle more precocious than the rat, and the cat much more so.


Online Editor - TABLE 20 (to be formatted) 
TABLE 20 Condensed


Ratios of the radial basal breadth of the inner pillar according to the turns of the

cochlea on age




RATIOS


BETWEEN TTTBN8



AGE


BODY WEIGHT


I-II


I-III


I-IV


days


grams





8


11


1 1.0


1 1.0


1 1.1


14


13


1.1


1.2


1.3


189


124


1.0


1.0


1.0


TABLE 21

Radial basal breadth of inner pillar in n (Retzius)


BABBIT


CAT


Age


Basal turn


Middle


Apical


Average


Basal


Middle


Apical


Average


days






New-born





11




2


3



12



7


15


12


15


14


10


15





10


17


18


18


18


11



15


15





14


15


15


12


14


30


9


12


15


12


Table 22 (chart 9) shows the values for the radial distance between the outer corner of the inner pillar (not pillar cell) and the inner corner of the pillar (not pillar cell) at the base, on age. At the bottom of the last column are given the ratios from 6 to 546, 12 to 546, and 20 to 546 days. As just stated, the inner, and especially the outer rods, do not appear in the respective pillar cells at the earliest stage, the latter becoming evident a bit later than the former. After six days of age the distance between them can be determined.


Online Editor - TABLE 22 (to be formatted) 
TABLE 22

Radial distance between the outer corner of the inner pillar and the inner corner of the outer pillar at base on age (chart 9)


AGE


BODY WEIGHT


TURNS OF THE COCHLEA M




I


II


III


IV


Average


days


grams







1


5









3


8









6


11


25


28


29


34


29


9


10


27


30


35


30


31


12


13


37


41


51


53


46


15


13


35


46


56


56


48


20


29


43


53


66


68


58


25


36


42


58


67


68


59


50


59


41


54


68


74


59


100


112


44


59


71


78


63


150


183


43


59


68


76


62


257


137


46


56


66


75


61


366


181


45


57


68


74


61


546


255


47


60


71


74


63


Ratios 6546 days 12546 " 20546 "



Chart 9. The radial distance between the outer corner of the inner pillar (not pillar cell) and the inner corner of the outer pillar (not pillar cell) at base, table 22, figure 2, distance 6.


As table 22 shows, this distance increases at first rapidly, then more slowly with age. This agrees with the growth of the membrana basilaris, as already noted. While the value at 546 days is over twice as large as at six days, it is but little larger than at twenty days, as the ratios show. Moreover, the distance increases from the base toward the apex rapidly up to turn


Online Editor - TABLE 23 (to be formatted) 
TABLE 23 Condensed

Ratios of the radial distance between the outer corner of the inner pillar and the inner corner of the outer pillar, at base according to turns of the cochlea on age




RATIOS BETWEEN TURNS




I-II


i-m


I-IV


days


grams





8


11


1 : 1.1


1 : 1.2


1 : 1.2


14


13


1.2


1.5


1.5


189


124


1.3


1.5


1.7


III and less rapidly to turn IV. This relation is more concisely presented in table 23. Retzius ('84) gives the value of this distance in the rabbit and the cat as follows (table 24).

The table 24 shows that there is no measurable distance between the outer corner of the inner pillar and the inner corner of the outer pillar at the very early stage in the rabbit, and this result is like that for the albino rat. Later the distance is larger in the rabbit than in the rat. The rate of increase of the values from the base to the apex is, however, similar in both forms. In the cat, on the other hand, there is already at birth a large distance between the pillars. The cochlea of the cat is therefore at this period more advanced in this character than that of the rabbit or rat, but in the cat also the distance tends to increase from the base toward the apex.


In table 25 (chart 10) are given the values for the radial distance between the habenula perforata and the outer corner of the inner pillar cell (resp. the inner corner of the outer pillar cell) at the base according to age. This table is derived from tables 18, 19, and 22. The values from one to nine days of age are from table 18. Those after twelve days consist of the sum of the values in table 19 plus the one-half of those given in table 22 (fig. 2 value for bracket 3 plus one-half the value for bracket 6).


Online Editor - TABLE 24 (to be formatted) 
TABLE 24

Radial distance between the outer corner of the inner pillar and inner corner of the

outer pillar in n (Retzius)


RABBIT


CAT


Age


Basal turn


Middle turn


Apical turn


Average turn


Basal turn


Middle turn


Apical turn


Average turn


days










New-born








64






2














3








45






7


57


75


75


69


50


75





10


52


72


74


66








11








75


95





14


63


100


99


87








30








66


93


90


83


The values increase gradually after birth till nine days, when they reach a maximum, and then decrease, but increase again very gradually till old age. If this method of measurement is accepted, then the inner corner of the inner pillar cell lengthens inward at the base in the earlier stages. At the time when the inner pillar reaches the habenula perforata, the outer corner of the inner pillar has not yet moved inward, and thus the breadth of the base is largest. After the inward wandering of the inner pillar cell, the base diminishes a little in its breadth; then it increases slightly with advancing age.

When considered according to the turn of the cochlea, this measurement generally increases from the base to the apex, but more rapidly from turn I to turn III, and only slightly from turn III to IV. Table 26 shows this relation. While at birth the ratio is in all turns the same, 1 :1.0, at other ages it is always higher. Retzius ( '84) gives the results obtained from the rabbit and the cat as follows (table 27).


Online Editor - TABLE 25 (to be formatted) 
TABLE 25

Radial distance between the habenula perforata and the outer corner of the inner

pillar cell (resp. the inner corner of the outer pillar cell) at base on

age. Derived from tables 18, 19 and 22 (chart 10)


AGE


BODY WEIGHT


TURNS OF THE COCHLEA M


I


II


III


IV


Average


days


grams







1


5


40


41


39


39


40


3


8


46


49


49


49


48


6


11


38


45


58


53


49


9


10


44


46


56


53


50


12


13


36


45


50


50


45


15


13


36


41


47


47


43


20


29


36


42


48


49


44


25 .


36


35


44


48


49


44


50


59


35


41


48


50


44


100


112


36


44


50


52


46


150


183


36


45


49


53


46


257


137


38


43


48


51


45


366


181


39


45


49


52


46


546


255


39


44


52


52


47


Ratios 1 546 days 9546 " 12546 " 20546 "


1.2 0.9 1.0 1.1


60

JLL

40 20


Chart 10 The radial distance between the habenula perforata and the outer corner of the inner pillar cell (resp. the inner corner of the outer pillar cell) at base, table 25, figure 2, distance 8.


Online Editor - TABLE 26 (to be formatted) 
TABLE 26 Condensed


Ratios of the radial basal distance between the habenula perfcrata and the outer

corner of the inner pillar cell (resp. the inner corner of the outer pillar

cell) at base on age according to the turns of the cochlea




RATIOS BETWEEN TURNS


AGE


BODY WEIGHT





I-I1


I-HI


I-IV


days


gram*





1


5


1 1.0


1 :1.0


1 :1.0


8


11


1.2


1.4


1.3


18


21


1.2


1.3


1.3


213


138


1.2


1.S


1.4


TABLE 27


Distance between the habenula perforata and the outer corner of the inner pillar

cell in n (Retzius)


Age


Basal turn


Middle

turn


Apical turn


Average turn


Basal turn


Middle turn


Apical turn


Average turn


days










New-born


30


45


39


38


60


60


60


60


2


30


36


30


32








3








44


60





7


37


46


45


43


45


69(?)


65


60


10


39


52


48


46








11








60


66


75


67


14


40


54


51


48








30









60


60




At the earlier stage this distance in the rabbit is a little less than in the rat. Soon after, however, it becomes about the same. In the cat the values are generally larger than in the rat.

5. Radial basal breadth of the outer pittar cett (including the outer pillar)

The measurement of the radial basal breadth of the outer pillar cell is difficult. At the earlier stage, in which the inner and outer pillar cells are in contact with each other along


Radial basal breadth of the outer pillar cell (including the outer pillar) from one

to nine days of age




TURNS OF THE COCHLEA M


AGE


BODY WEIGHT





I


II


III


IV


Average


days


grams


1


5


10


9


8


8


9


3


8


15


16


15


12


15


6


11


26


28


28


33


28


9


10


26


30


30


35


30


TABLE 29 Radial basal breadth of the outer pillar on age (chart 11)


AGE


BOOT WEIGHT


TURNS OF THE COCHLEA M


I


II


III


IV


Average


days


grams







1


5









3


S









6


11


10


14


16


17


14


9


10


15


18


18


21


18


12 .


13


14


23


25


22


21


15


13


17


21


23


20


20


20


29


13


13


16


15


14


25


36


14


13


14


14


14


50


59


14


14


15


14


14


100


112


14


15


16


15


15


150


183


15


15


15


16


15


257


137


15


16


17


17


16


366


181


15


16


17


18


16


546


255


16


15


17


17


16


Ratios

1 2

40 A 20

n


6546 days 1 2546 " 0546 "


1.1 0.8 1.1




Chart 11 The radial basal breadth of the outer pillar (not pillar cell) table 29, figure 2, distance 7.



their whole length, we can easily measure this distance. After twelve days, however, the breadth consists of the sum of the radial breadth of the outer pillar and the half of the radial distance between the outer corner of the inner pillar and the inner corner of the outer pillar, as previously explained.

In table 28 are given the values for the radial basal breadth of the outer pillar cell (including the outer pillar) from birth to nine days of age. These values show a rapid increase. According to the turn of the cochlea, the breadth at birth diminishes from the base to the apex. At three days it increases already in turn II, but at the later ages it increases gradually from the base to the apex.

TABLE 30 Condensed

Ratios of the radial basal breadth of the outer pillars on age according to the

turns of the cochlea




RATIOS BETWEEN TURNS


AGE


BODY WEIGHT





I-II


I-III


I-IV


days


grams





8


11


1 -1.2


1 1.3


1 1.5


14


13


1.4


1.5


1.3


189


124


1.0


1.1


1.1


In table 29 (chart 11) are given the values for the radial basal breadth of the outer pillar (not pillar cell). As in the case of the inner pillar, here also the outer pillar first appears distinctly at six days of age. After the continuous increase of the values till twelve to fifteen days, they decrease suddenly at twenty days, and then increase again very slowly. This relation is clearly shown by the ratios at the bottom of the last column. That the values tend to increase from the base toward the apex is also shown, though there are some exceptions. Table 30 gives the condensed results.

From Retzius' work ('84) we have calculated the values for the radial basal breadth of the outer pillar in the rabbit and cat as follows (table 31).

There are large differences between my results and those of Retzius during the earlier stage, especially in the rabbit.


60


ANATOMICAL AND PHYSIOLOGICAL STUDIES ON


At birth, the inner pillar has not yet distinctly developed at the base of the pillar cell in the rabbit and the rat, as above stated. We know that the development of the elements of the cochlea proceeds generally from the axis to the periphery, as

TABLE 31

Radial basal breadth of outer pillar measured in n (from Retzius)


RABBIT


CAT


Age


Basal turn


Middle turn


Apical turn


Average


Basal turn


Middle turn


Apical turn


Average


days


,



New-born


15?


12?


7?


11?


25


15





2


50


45


44


46








3








20






7


28


28


17


24


18


20


18


19


10


31


30


37


33








11








30


19





14


28


25


18


24








30








10


15


15


13


TABLE 32


Radial basal breadth of the outer pillar cells on age, based on tables 22, 28, and

29 (charts 12 and 18)


AGE


BODY WEIGHT


TURNS OP THE COCHLEA M


I


II


III


IV


Average


days


grams







1


5


10


9


8


8


9


3


8


15


16


15


12


15


6


11


26


28


28


33


28


9


10


26


30


30


35


30


12


13


33


38


48


52


43


15


13


35


44


50


48


44


20


29


35


40


49


49


43


25


36


35


42


48


48


43


50


59


35


41


49


51


44


100


112


36


45


52


54


47


150


183


36


45


49


54


46


257


137


38


44


50


53


46


366


181


38


43


51


55


47


546


255


40


45


53


54


48


Ratios 1 546 days

9546 " 12546 " 20546 "


1 :5.4

1.6
1.1
1.1


Held ('09) and others have pointed out. Yet, according to Retzius, the outer pillar develops in the rabbit earlier than does the inner pillar. This result seems to me very peculiar, but, at present, I am unable to explain it.

In table 32 (charts 12 and 13) are given the values for the radial basal breadth of the outer pillar cells. These data are derived from tables 22, 28, and 29. At the foot of the last column are given the ratios from 1 to 546, 9 to 546, 12 to 546, and 20 to 546 days. The values increase rapidly during the earlier stage, but after twelve days very slowly, as the ratios show. The breadth is, at birth, largest in the basal and smallest in the apical turn. Very soon, however (six days), the reverse relation appears, and the breadth increases from the base to turn III relatively rapidly, but from turn III to IV slowly. In table 33 the ratios are given in a condensed form. The radial breadth of the outer pillar cells as given by Retzius ('84) are as follows (table 34.)



Chart 13 The radial basal breadth of the outer pillar cell, according to the turns of the cochlea, table 32, figure 2, distance 9.



TABLE 33 Condensed

Ratios of the radial basal breadth of the outer pillar cells on age according to

turns of cochlea




RATIOS BETWEEN TtTRNS


AGB


BODY WEIGHT





I-II


i-in


I-IV


days


grams





1


5


1 :0.9


1 0.8


1 :0.8


8


11


1 1.1


1.2


1.3


18


21


1.2


1.4


1.4


213


138


1.2


1.4


1.4


TABLE 34 Radial basal breadth of the outer pillar cells in n (Retzius)


RABBIT


CAT


AOE


Basal turn


Middle turn


Apical turn


Average turn


Basal turn


Middle turn


Apical turn


Average turn


days


New-born


21


22


23


22


36


30


30


32


3


30


40


30


33








3








36


30





7


65


66


60


64


36


54


36


42


10


52


60


69


60






'


11








50


60


18


43


14


57


80


80


72








30









60


60




This table shows that the breadth of the outer pillar cell increases in the rabbit and the cat continuously from birth to old age, as I have found in the rat. Also the value is generally smallest in the base, largest in the apex, though there are some exceptions. The main differences between the results of Retzius and mine is that the values in the rabbit are larger than in the rat. This is probably due to the differences in the size of the animals.


6. The radial distance between the habenula perforata and the outer border of the foot of the outer pillar cell

The determination of this distance is deemed necessary not only as a datum on growth in general, but also for its bearing on the difficult question of the shifting of the outer pillar cell, to be discussed later. On the other hand, this distance is identical with the radial length of the zona arcuata of the membrana basilaris (table 7. inner zone).

In table 35 (chart 14) are given the values for the radial distance between the habenula perforata and the outer corner of the outer pillar cell at base. At the foot of each column are given the ratios at 1 to 12, 1 to 20, 1 to 546, and 20 to 546 days. As table 35 shows, the distance increases continuously from birth to old age, rapidly up to twelve days, but later gradually. Up to three days the distance is slightly larger in the lower turns, but after this age the relation is reversed, and this persists through life.

The increasing ratio of the distance for each turn according to age is smallest in turn I and largest in turn IV. The ratios for the condensed data are given in table 36. While the ratio at birth is the same in each turn, 1:1.0, that of turn I to II is smallest for every condensed age. Also it is to be seen that the increase of the ratio in turn I to II is smallest and that in turns I to IV is largest. In Retzius' work ('84) we find the following values for this distance (table 37).

Table 37 shows that in the rabbit the growth changes are similar to those in the rat, though the absolute values are somewhat larger. As hi preceding determinations, the values for the cat do not stand in the same relation as those for the rabbit, but indicate precocity. Some corresponding observations by Hensen, Bottcher, and others will be presented later.

7. The greatest height of the greater epithelial ridge (der grosse Epithelwulst (Bottcher) s. Organon Kollikeri) resp. of the inner supporting cells

(fig. 4, G). The so-called greater epithelial ridge is a prominence formed by high cylindrical pseudostratified cells. It is situated axialward on the tympanic wall and continued outward to the lesser epithelial ridge. About the fate of this ridge there were various divergent opinions among the older authors. Now, the view of Bottcher ( '69) is generally accepted. This large prominence vanishes during development, and instead of it a deep and wide furrow lined with low epithelium appears. These epithelial cells become peripherally higher and finally lean


Online Editor - TABLE 35 (to be formatted) 
TABLE 35

Radial distance between habenula perforata and the outer corner of the outer pillar cells at base on age (chart 14)- For the average values see the third column in table 9


AGE


BODY WEIGHT


TURNS OF TBE COCHLEA M


I


II


III


IV


Average


days


yrams







1


5


50


50


48


48


49


3


8


63


65


64


58


63


6


11


64


73


86


86


77


9


10


70


76


86


86


80


12


13


69


83


98


100


88


15


13


70


84


98


95


87


20


29


71


81


96


98


87


25


36


71


86


95


97


87


50


59


69


83


96


102


88


100


112


73


88


101


106


92


150


183


73


89


98


107


92


257


137


76


87


98


107


92


366


181


76


89


100


107


93


546


255


78


89


104


106


94


Ratios 1 12 days 1 20 " 1546 " 20546 "


1.4 1.4 1.6 1.1


1.7
1.6
1.8
1.1


1 -2.0

2.0
2.2


1 :2.1

2.0
2.2
1.1


1.8
1.8
1.9
1.1


100


80


60


40


Chart 14 The radial distance between the habenula perforata and the outer corner of the outer pillar cell at base, table 35, figure 2, distance 5.


on the inner supporting cells, which are termed ' Grenzzellen ' by Held ('02). The latter belong, of course, to this ridge, since the inner hair cell marks the outmost row in the ridge. The 'Grenzzellen' of Held, however, are different from other high cylindrical cells in the ridge, as they have a very intimate relation with the ' Phalangenzellen ' of Held, stand with their bases just

TABLE 36 Condensed

Ratios of the radial distance between the habentda perforata and the outer corner of the outer pillar cells at base on age




RATIOS BETWEEN TURNS


AVERAGE AGE


AVERAGE BODY




WEIGHT


I-II


i-in


I-IV


days


grams





1


5


1 :1.0


1 :1.0


1 :1.0


8


11


1.1


1.3


1.2


18


21


1.2


1.4


1.4


213


138


1.2


1.3


1.4


TABLE 37

Radial distance between habenula perforata and the outer corner of the outer pillar cells at base in n (Retzius)


RABBIT


CAT


Age


Basal


Middle


Apical


Average


Basal


Middle


Apical


Average



turn


turn


turn


turn


turn


turn


turn


turn


days










New-born


75


80


75


77


105


105


120


110


2


80


90


100


90








3








80


120





7


100


115


107


107


78


110


120


103


10


100


120


129


116








11








120


129


108


119


14


106


140


129


125








30








85


120


120


108


outward from the habenula perforata and serve to support the inner hair cell as Deiters' cells support the outer hair cells.

Thus the greater ridge includes in its prominence three kinds of cells, the high cylindrical cells, the 'Grenzzellen' of Held and the inner hair cell.

The greatest height of this ridge is not situated at a fixed point, but first lies somewhat outward from the middle part and


66


ANATOMICAL AND PHYSIOLOGICAL STUDIES ON


after the furrow appears, passes outward towards the inner supporting cells. Thus the greater ridge decreases in thickness from birth to nine days of age, then increases gradually to twenty days. After twenty-five days the values diminish again very slowly but continuously.

In table 38 (charts 15 and 16) are given the values of the greatest height of the greater epithelial ridge from the basilar membrane

TABLE 38

Greatest height of the greater epithelial ridge (resp. of the inner supporting cells)

on age (charts 15 and 16)



Bodv wcifitlitj


TURNS OF COCHLEA M




I


II


III


IV


Average height


days 1


grams 5


68


65


66


63


66


3


8


49


49


56


57


53


6


11


40


40


41


40


40


9


10


36


40


41


42


40


12


13


38


41


48


53


45


15


13


44


46


52


58


50


20


29


50


53


63


66


58


25


36


51


51


63


63


57


50


59


50


50


59


63


56


100


112


48


49


59


63


55


150


183


47


49


56


61


53


257


137


47


51


56


62


54


366


181


46


49


57


60


54


546


255


44


50


56


60


53


Ratios 1 9 days 1:0.6


12 20 " :1.3


12546 " :1.2


20546 " :0.9


1546 " :0.8


through the summit of the supporting cells, according to age. At the bottom of the last column is given the ratio at 1 to 9, 1 to 546, 12 to 20, 12 to 546, and 20 to 546 days of age.

The values in turn I are at birth the largest, but at three days the relation is reversed and remains so in the later age groups. Table 39 shows this relation from the condensed data.

Retzius ('84) gives in the rabbit and cat the following values (table 40).

In the rabbit the values decrease from birth till ten days, then increase; therefore, they agree in general with my results


50 40 30



25


50 50 10O 20O 30O 40O 500

Chart 15 The greatest height of the greater epithelial ridge (resp. of the inner supporting cells) table 38, figures 4 to 12.


70 44

60

5O 40 30


s


o


25


50


50 IOO 20O 3OO 4OO 500


Chart 16 The greatest height of the greater epithelial ridge (resp. of the inner supporting cells) arranged according to the turns of the cochlea, table 38, figures 4 to 12.

on the rat, while in the cat they diminish from birth till thirty days though irregularly.

The absolute values are greater for the rabbit than for the rat during the earlier stage, but afterwards they are similar.


68


In the cat the early data give values similar to those for the rat, but the later values are lower.

Bottcher's observations ('69) on the cat, calf, and sheep also give larger values than mine. In the cat the greater ridge has an average height of 75 [x and in both the others of 90 \L. Therefore, even in the same animal (cat) there are large differences in the data presented by different authors.

TABLE 39 Condensed

Ratois of the greatest height of the greater epithelial ridge (resp. of the inner supporting cells) according to the turns of the cochlea on age


Average age


Average body weight


RATIOS BETWEEB TURNS


I-II


i-in


I-IV


days


grams





1


5


1 :1.0


1 1.0


1 :0.9


8


11


1.0


1.1


1.2


18


21


1.1


1.2


1.3


213


138


1.0


1.2


1.3


TABLE 40


Greatest height of the greater epithelial ridge measured through the inner supporting

cells, in p. (Retzius)


RABBIT


CAT


Age

days


Basal turn


Middle turn


Apical turn


Average turn


Basal turn


Middle turn


Apical turn


Average turn


New-born


78


99


90


89


45


75


6S


63


2


60


90


90


80








3








40


84





7


51


68


63


61


40


54


63


52


10


36


54


56


49








11








50


58


66


58


14


51


51


51


51








30








30

.


45


45


40


Gottstein ('72) thinks that the greater epithelial ridge does not diminish its height for some time after birth, but through the outward development of the labium tympanicum, and in addition to this through the growth of the labium vestibulare, the sulcus spiralis internus arises. He does not give measurements.


His idea was strongly opposed by Bottcher ( 72) and my results are also opposed to Gottstein's view.

8. The radial distance between the labium vestibulare and the habenula perforata

The purpose of this measurement is to determine how the habenula perforata stands in relation to its surroundings during the development of the cochlea. The measurements of this distance is difficult. During the earlier stages, the labium vestibulare is quite undeveloped, especially in the upper turns. At birth we see on the inner surface of the greater epithelial ridge a small prominence under which the epithelial cells are short and pressed together so that the nuclei seem to be arranged in several rows (fig. 4). This appearance is due to the invasion of the subjacent connective tissue into the epithelium.

Thus the vestibular lip arises. We do not see a furrow at this time and cannot use the top of the furrow as a point for measuring as did Hensen ('63) in the ox and Bottcher ('69); in the embryo cat). To the measure the distance between the insertion of Reissner's membrane and the habenula perforata has no meaning for my purpose, because the length of the limbus laminae spiralis changes with age.

Thus I have measured the distance between the small epithelial prominence on the axial side of the greater ridge, corresponding to the edge of the labium vestibulare, and the habenula perforata.

In table 41 (charts 17 and 18) are given the -values of the radial distance between the labium vestibulare and the habenula perforata. At the foot of the last column are given the ratios from 1 to 546, 9 to 546, and 20 to 546 days. As we see, the values are a little bit smaller at the earlier stage. After nine days they are almost the same in every stage. The small differences at the earlier and later stages are probably due to the retarded development of the labium vestibulare.

When we consider the values for this distance in each turn, it is evident that these increase from base to apex. In the condensed table 42 this relation is shown.

Hensen ('63) finds that the distance from the top of the furrow to the habenula perforata is in the fetal calf and in the ox the. same, 255 [x. He considers the holes of the habenula as a ' punctum fixum. ' Bottcher ('69, 72) agrees with Hensen and gets in the cat embryo and the adult cat the following values (table 43).

TABLE 41

Radial distance between the labium veslibulare and the habenula perforata on age

(charts 17 and 18)


AGE


BODY WEIGHT


TURNS OP THE COCHLEA M


I


II


III


IV


Average


days


grams







1


5


100


108


120


130


115


3


8


80


110


130


137


114


6


11


82


105


135


137


115


9


10


83


108


137


145


118


12


13


80


102


139


148


117


15


13


82


107


144


157


122


20


29


84


106


146


153


122


25


36


82


105


147


150


121


50


59


82


104


137


147


118


100


112


80


103


151


154


122


150


183


80


107


141


144


118


257


137


83


105


143


150


120


366


181


79


105


135


149


117


546


255


79


105


143


150


119


Ratios 1 546 days

9546 " 20546 "


1.0 1.0 1.0


TABLE 42 Condensed


Ratios of the radial distance between the labium vestibulare and the habenula perforata according to turns of the cochlea




RATIOS BETWEEN TURNS


AVEKAGE AGE


WEIGHT


I-II


I-II I


I-IV


days


grams





1


5


1 1.1


1 1.2


1 1.3


5


10


1.3


1.6


1.8


141


93


1.3


1.7


1.8


Comparing the results of both Hensen and Bottcher with my own, the values obtained by Hensen are large, as would be expected in the larger animal. The cat and rat however, give similar values. We conclude, therefore, that broadly speaking, the habenula perforata is to be considered as a 'punctum fixurn, 'at least after birth.

9. The radial distance between the labium vestibulare and the inner edge of the head of the inner pillar cell

To measure the


140


120


1OO


AGE DAYS


25


50


50 1OO 2OO 3OO 40O 500

Chart 17 The radial distance between labium vestibulare and the habenula perforata, table 41, figure 10.


Chart 18 The radial distance between labium vestibulare and the habenula perforata according to the turns of the cochlea, table 41.

radial breadth from the labium vestibulare to the inner edge of the head of the inner pillar cell, I have used, at earlier stages, as in the preceding chapter, the same small prominence as an inner fixed point (fig. 4). In table 44 (chart 19) are given the values for this radial distance according to age. At the bottom of the last column are given the ratios from 1 to 9, 1 to 546


TABLE 43

Distance between labium vestibulare and habenula perforata in n (Bottcher)


PLACE OF


CAT EMBRYO 9 CM.


CAT EMBRYO 11 .5


CAT THREE DAYS


ADULT CAT


MEASUREMENT


LONG


CM. LONG


OLD



I turn


120


120


120


100


II turn


130


130


130


110


III turn


150


140


140


130


TABLE 44


Radial distance between the labium veslibulare and the inner edge of the head of the inner pillar cell on age (chart 19)


AGE


BODY WEIGHT


TURNS OF THE COCHLEA M


I


II


ill


IV


Average


days


grams







1


5


111


126


138


130


126


3


8


84


118


150


170


131


6


11


88


119


159


180


136


9


10


94


131


168


179


143


12


13


69


97


138


156


115


15


13!


",' 66


103


137


149


114


20


29


66


103


137


148


114


25


36


65


100


136


148


112


50


59


61


98


129


144


108


100


112


64


99


139


153


114


150


183


60


99


129


143


108


257


137


67


100


134


149


113


366


181


60


102


130


151


111


546


255


55 :..


99


128


143


106


Ratios 1 9 days

1546 " 12546 "


1.1

0.8 0.9


TABLE 45 Condensed


Ratios of the radial distance between the habenula perforata and the inner edge of

the head of the inner pillar cell according to the turns of

the cochlea on age




KATIOS BETWEEN TURNS


AVERAGE AGE


WEIGHT







I-II


I-HI


I-IV


days


grams





1


5


1 1.1


1 \.9


1 1.2


6


10


1.4


1.8


2.0


154


102


1.5


2.1


2.3


and 12 to 546 days of age. As the table shows, the values increase in general from birth to nine days; therefore, the surface of the greater epithelial thickening from the labium vestibulare to its outer boundary becomes, during the earlier stage, wider and wider, then decreases sharply, and after that continuously but slowly. This sudden diminishing of the distance has a very intimate relation with the change in the form of the papilla spiralis at this stage of development.

This point I will discuss later.

That the values increase from the base to the apex first rapidly and later less rapidly, is also to be seen here. Table 45 shows this relation clearly. It is remarkable, however, that the ratio becomes


Chart 19 The radial distance between the labium vestibulare and the inner edge of the head of the inner pillar cell, table 44.

at each turn larger with age, although the absolute value is after nine days generally smaller than at the preceding age. Therefore, we see that the diminution of the distance after nine days is largest in the basal turn and smallest in the apical. Hensen ('63) asserts that there is a movement axialward of the organ of Corti (resp. the head of the pillar cell), but gives no measurements. Neither Bottcher nor Retzius measured this distance. Prentiss ('13, page 445) states that "the distance between the inner angle of the cochlea and the pillar cells, two definite points, may be measured with considerable accuracy and shows no important change in the position of the spiral organ from the 13 cm. to the 18.5 cm. stage, nor later in the new born animal" (pig) But he also does not record his measurements.


Hardesty ('15, p. 54) says "that the space occupied by the width of the greater epithelial ridge increases throughout the coils of the cochlea up to pigs of 15 to 16 cm., and thereafter it begins to decrease very perceptibly." He measured the width from the membrana propria of the epithelium of the greater ridge, at its most axial extension under Huschke's teeth, to the apical end of the inner hair cell of the spiral organ. " The

TABLE 46

Vertical distance from the membrana basilaris to the surface of the pillar cells on

age (chart 20}




TURNS OF THE COCHLEA M


AGE


BODY WEIGHT





I


II


ill


IV


Average


days


grams







1


5


35


36


39


36


37


3


8


30


29


29


29


29


6


11


29


32


31


29


30


9


10


32


33


35


36


34


12


13


41


45


50


52


47


15


13


44


48


53


57


51


20


29


53


57


67


71


62


25


36


55


56


66


68


61


50


59


53


55


67


68


61


100


112


53


54


64


67


60


150


183


52


54


63


66


59


257


137


53


56


63


69


60


366


181


51


56


66


67


60


546


255


52


55


62


66


59


Ratios 1 12 days 1-1.3


1 20 " 1.7


1546 " 1.6


12546 " 13


20546 " 1.0


method of measurement differs from mine, so the results cannot be compared directly. While the distance in the rat increases to nine days of age, that in the pig decreases perceptibly in fetuses more than 16 cm. long.

According to Hardesty ('15, p. 55). "the decrease in the I and III half turns may be as much as one-third of the width of the greater ridge when at its maximum size and activity. " And "after the tectorial membrane is about completely produced,


GROWTH OF THE INNER EAR OF ALBINO RAT


75


and while the spiral organ is enlarging, the inner hair cells, and therefore the organ, may be moved in the apical coil of the cochlea axialward a distance of about half the maximum width of the greater epithelial ridge, "

The differences of the values in the rat at 9 and 546 days are in the basal and apical turn about the same, 39 and 36 n, respectively (table 44). Thus while the inner edge of the inner pillar cell approaches at 546 days in the basal turn by as much as 41 per cent of the distance present at nine days, that in the apex moves only 20 per cent inward in old age. This result is the reverse of that obtained in the pig by Hardesty. The reason for this contradiction I will discuss later.


Chart 20 The vertical distance from the membrana basilaris to the surface of the pillar cells, table 46, figure 1, 1-1.


10. The vertical distance from the membrane basilaris to the summit of the pillar cells

The method of getting the vertical distance from the membrana basilaris to the surface of the pillar cells is shown in figure 1, line 1-1. In table 46 (chart 20) are given the values thus obtained. At the foot of the last column are given the ratios of this distance at 1 to 12, 1 to 20, 1 to 546, 12 to 546, and 20 to 546 days. The average value is relatively large at birth, it diminishes at three days, then increases more rapidly to twenty days. After this it decreases very slowly. The maximum height of the arch of Corti is at twenty days of age. Comparing the values for the height in each turn, we find that from nine days they increase from the basal to the apical turn. This relation can be easily seen in table 47.

Retzius ( '84) gives in the rabbit and cat the following values (table 48).


TABLE 47 Condensed


Ratios of the vertical distance from the membrana basilaris to the surface of the pillar cells according to the turns of the cochlea




RATIOS BETWEEN TURNS



AVERAGE BODY



AVERAGE AGE


WEIGHT







I-II


i-ni


I-IV


days


grams





1


5


1 :1.0


1 : 1.1


1 : 1.0


1


11


1.1


1.1


1.1


18


21


1.1


1.2


1.3


213


138


1.0


1.2


1.3


TABLE 48 Vertical distance from the membrana basilaris to the summit of the pillar cells


BABBIT


CAT


Age


Basal

turn


Middle turn


Apical turn


Average


Basal turn


Middle turn


Apical turn


Average


days


New-born


45


70


61


59


45


60


48


51


2


45


69


40


51








3








39


60





7


46


60


60


55


45


47


50


44


10


45


69


69


61








11






JK


50


60


42


51


14


45


57


66


56








30






' }'


33


51


57


47


Table 48 shows that the height of the arch of Corti in the rabbit approximates that in the rat, though there are considerable differences in the earlier stages. In the former the arch of Corti develops after: birth only a little, and is therefore more precocious than in the rat. In the cat the same relation is to be seen, but the absolute values in the latter animal are smaller than in either the rabbit or the rat.


11. The greatest height of the tunnel of Corti

Some authors have reported in several animals the appearance of the tunnel of Corti just after birth, or even in later intrauterine life. In the rat, however, it first appears through all the turns after the ninth day. Sometimes we see it at nine days in the lower turn, though not yet in the upper. The method of measuring the height is shown in figure 1, line 1-1'. Table 49 (charts 21 and 22) gives the values for the greatest height of the tunnel of Corti. At the foot of the last column are given the ratios from 12 to 25, 12 to 546, and 25 to 546 days.

As the table shows, the space appears in all the turns at twelve days and has considerable height. This increases to twenty-five days, than decreases very slowly. This increase and decrease correspond to the changes in the distance of the summit of the pillar cells from the basilar membrane.

When we consider the height in each coil of the cochlea, we find the value increases from the base to the apex, first rapidly then slowly. In table 50 this relation is clearly shown.

Retzius ('84) gives the values for the adult rabbit, man and cat (one month) as follows (table 51).

According to this table, the average height is in the adult man, cat, and rabbit somewhat less than in the rat.

12. The height of the papilla spiralis at the third series of the outer hair cells

The measurements were taken along the line 2-2 shown in figure 1. The growth of this vertical height depends not only upon the increase of the length of the corresponding outer hair cell, but chiefly upon the development of the Deiters' cells, especially of the outermost row, and of the sustentacular cells of Hensen.

In table 52 (charts 23 and 24) are given the values for this vertical height of the papilla spiralis at the third series of the outer hair cells according to age. At the bottom of the last column are the ratios at 1 to 12, 1 to 20, 1 to 546, and 20 to 546 days. The heights decrease at three days, but increase from nine to twelve days very rapidly, nearly doubling their minimal values, and reach a maximum at twenty days. After that time they decrease very gradually to the end of the record. Therefore, the difference between the ratios at 1 to 20 and 1 to 546 days is very small.

Online Editor - TABLE 49 (to be formatted) 

TABLE 49 Greatest height of the tunnel of Corti on age (charts 21 and 22}


AGE


BODY WEIGHT


TURNS OP THE COCHLEA M


I


II


ill


IV


Average


days


grams







1


5









3


8









6


11









9 1


10









12


13


29


33


39


37


35


15


13


31


34


42


46


38


20


29


37


42


52


56


47


25


36


39


41


54


56


48


50


59


38


41


53


57


47


100


112


38


43


51


56


47


150


183


37


41


49


54


45

257


137


38


43


51


56


47


366


181


37


41


52


53


46


546


255


36


39


48


53


44


Ratios 12 25 days 12546 " 25546 "


1.4 1.3 0.9


1 In one case nine days old which could hear the space was found through all the turns of the cochlea.


Online Editor - TABLE 50 (to be formatted) 
TABLE 50 Condensed

Ratios of the greatest height of the tunnel of Corti according to the turns of the

cochlea on age




, RATIOS BETWEEN TURNS



AVERAGE BOOT



AVERAGE AGE


WEIGHT







I-II


i-ni


I-IV


days


grams





12


13


1 : 1.1


1 1.3


1 1.3


18


21


1.1


1.4


1.5


213


138


1.1


1.3


1.4


Online Editor - TABLE 51 (to be formatted) 
TABLE 51

The greatest height of the tunnel of Corti in n (Retzius)


RABBIT


CAT (one month)


MAN


Basal


Middle


Apical


Average


Basal


Middle


Apical


Average


Basal


Middle


Apical


Average


30


39


36


35


18


37


36


30


28


45


49


41


At twelve days and after, the values for the height increase in passing from the base to the apex, at first rapidly, then more slowly. In the earlier stages this relation is obscure or reversed.



Chart 21 The greatest height of the tunnel of Corti, table 49, figure 1, 1-1


Chart 22 The greatest height of the tunnel of Corti, according to the turns of the cochlea, table 49.

In the condensed table 53 are given the ratios in each turn. While the ratio of each turn before eight days is about 1:1.1, and between turns I and II remains constant in the later age, that for I to III and I to IV is at 18 and 213 days decidedly larger. Therefore, the increase of the height is most marked in the III and IV turn, as shown in chart 24.


Online Editor - TABLE 52 (to be formatted) 
TABLE 52

Height of the papilla spiralis at the third series of outer hair cells on age (charts 23 and 24)


AGE


BODY WEIGHT


TURNS OF THE COCHLEA M


I


II


III


IV


Average


days


grams







1


5


35


35


39


28


34


3


8


22


23


25


26


24


6


11


25


24


25


23


24


9


10


28


28


27


28


28


12


13


40


49


54


56


50


15


13


46


53


65


66


58


20


29


56


61


76


81


69


25


36


56


61


76


78


68


50


59


53


59


78


80


68


100


112


54


59


74


79


67


150


183


55


57


75


77


66


257


137


54


59


74


81


67


366


181


5?


58


75


78


66


546


255


52


58


72


75


64


Ratios 1 12 days 1 1.5 1 20 " 2.0


1546 " 1.9


20546 " 0.9


Online Editor - TABLE 53 (to be formatted) 
TABLE 53 Condensed


Ratios of the height of the papilla spiralis at the third series of outer hair cells according to the turns of the cochlea on age


AVERAGE AGE


AVERAGE BODY WEIGHT


BATIOS BETWEEN TURNS


I-II


i-ni


I-IV


days


grams





1


5


1 :1.0


1 :1.1


1 0.8


8


11


1.1


1.1


1.1


18


21


1.1


1.4


1.5


213


138


1.1


1.4


1.5


TABLE 54 Height of the papilla spiralis at the third scries of outer hair cells in n (Retzius)


BABBIT


CAT


AGE


Basal turn


Middle turn


Apical turn


Average


Basal turn


Middle turn


Apical turn


Average


days










New-born


48


70


60


59


45


60


45


50


2


45


70


54


56








3








40


58





7


54


69


66


63


42


5<


48


49


10


42


86


84


71








11








60


72


42


58


14


60


87


90


79








30








36


57


70


54


80


GROWTH OF THE INNER EAR OF ALBINO RAT


81


Retzius ('84) finds in the rabbit and cat the [values for this height given in (table 54).

Comparing these average numbers with mine, it appears that the height in the rabbit is greater, and in the cat smaller than


u

70 5O 30 10


k


AGE


o


25 5O 50 |OO 2OO 3OO 40O 5OO


Chart 23 The height of the papilla spiralis at the third series of the outer hair cells, table 52, figure 1, 2-2.


90


70


50


30


10



AGE DA.YS


O


25


50


5O 1OO 2OO 3OO 4OO 5OO


Chart 24 The height of the papilla spiralis at the third series of the outer hair cells, according to the turns of the cochlea, table 52.

in the rat. In both animals the values increase rapidly at ten to eleven days of age, as in the albino rat, but the height in these animals is at the earlier stage almost twice as large as in the rat. Hardesty ('15) measured the thickness of the organ of Corti in


82


ANATOMICAL AND PHYSIOLOGICAL STUDIES ON


the pig in a somewhat different way, using the vertical line from the basilar membrane proper through the m'ddle of the outer hair cell to the surface of the organ, and found the increase in thickness to take place most rapidly at the stages before full term, though it seems to continue after birth. I have not made cor TABLE 55

Greatest height of Hensen's supporting cells on age (chart 25)


AGE


BODY WEIGHT


TURNS OP THE COCHLEA M


1


II


III


IV


Average


days


grams







I


5


36


36


38


31


35


3


8


18


21


21


24


21


6


11


21


20


21


18


20


9


10


20


23


23


24


23


12


13


40


49


56


58


51


15


13


44


56


69


72


60


20


29


64


64


86


87


75


25


36


69


71


84


86


78


50


59


71


74


87


89


81


100


112


77


. 78


87


89


83


150


183


76


77


<3


93

85

257


137


81


83


89


89


86


366


181


82


83


89


91


86


546


255


79


79


92


93


86


Ratios 1 6 days

1 12

1 20

1546

6 12

6 20

6546 12 20 12546 20546


0.6 1.5 2.1 2.5 2.6 3.8 4.3 1.5 1.7 1.1


responding studies on the rat. In the latter animal, however, the rapid increase usually appears at twelve days of age, when the animal as a rule first responds to auditory stimuli, and thus we have a correlation between the development of the organ and the beginning of the function, which will be discussed later. In the case of one rat that could hear at nine days this change had already occurred.

13. The greatest height of Hensen's supporting cells

The older authors (Kolliker and others) thought that the arch of Corti marks the highest point of the papilla which slopes from this point gradually outward to the cells of the zona pectinata. Against this erroneous idea Hensen ('63) first published observations showing that the highest point is in the papilla which ascends laterally from the outer hair cells, and then slopes abruptly and passes over to the cells of the sulcus spiralis externus. We term this prominence Hensen's prominence and the cells, Hensen's supporting cells. The measurements of the height of these cells were made along 3 3 in figure 1. Table 55 (chart 25) shows the values for the greatest vertical height of these supporting cells according to age. At the foot of the last column are given the ratios from 1 to 6, 1 to 12, 1 to 20, 1 to 546, 6 to 12, 6 to 20, 6 to 546, 12 to 20, 12 to 546, and 20 to 546 days. The values diminish at the earlier stage from birth to six or nine days. At twelve days they increase suddenly, more than doubling. After that they increase to old age, rapidly up to twenty days and then slowly. Here also the height increases from the base to the apex, the most marked increase occurring between turns II and III. In table 56 this relation is clearly shown. Retzius ('84) gets values of this height in the rabbit and cat as follows (table 57).


Chart 25 The greatest height of Hensen's supporting cells, table 55.


In both the rabbit and the cat the height increases at ten to eleven days very considerably, as it does in the rat. Only there is a large difference in the absolute values for the three animals, these being largest in the rabbit and smallest in the cat. The final average values in the cat are nearly the same as those in the rat at the same age.

Kolmer ('07) finds in the calf the value in the highest point of the organ of Corti in the region of the innermost Hensen's cells as follows:

In the basal turn, 84 [A

In the second turn, 90 JJL

In the third turn, 105 [JL

Average, 93 [i.

Hensen ('63) gives in man the average height of the papilla as 90 (JL in the hamulus and 60 [j. in the radix. Thus the height of Hensen's cells is different in different animals.

When we consider the growth in the height of Hensen's cells we can picture the change of the form in the papilla spiralis. As shown already, the height of the pillar cells is largest at the earlier stage, when the papilla has its highest point at the summit of the arch of Corti, and slopes downward to the Hensen's cells. But at twelve days the form is reversed, and the highest point is in Hensen's prominence from which the surface slopes inward more or less steeply to the surface of the pillar cells and the inner supporting cells. Thus the surface of the papilla does not run parallel to the basilar membrane, but makes with it a sharp angle opening outward. This angle has been measured.

14. The angle subtended by the extension of the surface of the lamina relicularis with the extended plane of the membrana basilaris

As just stated, the lamina reticularis after the earlier stages is not parallel to the membrana basilaris, but forms an angle with it. The measurements of this angle , were taken as shown in lines 4~4' i n figure 1. In table 58 (chart 26) are given the values for the angle in degrees. Before nine days there is no appreciable angle. From twelve to twenty days the angle increases rather rapidly, and after twenty days continuously but slowly. The ratio at the bottom of the last column shows this clearly.

Comparing the values of the angle in each turn according to age, there is no clear evidence that it increases from base to apex, though it tends to be largest in turn III and next largest in turn II. The condensed table 59 shows these relations. Retzius ( ; 84) finds this angle in the rabbit and cat to be as in table 60.

TABLE 56 Condensed

Ratios of the greatest height of Hensen's supporting cells according to the turns of the cochlea


RATIOS BETWEEN SUCCESSIVE TURNS


AVERAGE AGE


AVERAGE BODY




WEIGHT


1





I-II


I-III


I-IV


days


grams





1


5


1 1.0


1 1.1


1 0.9


8


11


1.1


1.2


1.2


18


21


1.1


1.4


1.5


213


138


1.0


1.2


1.2


TABLE 57 Greatest height of Hensen's supporting cells in M (Retzius)


RABBIT


CAT


Age Days


Basal turn


Middle


Apical


Average


Basal


Middle


Apical


Average


Xew-born


38?


60?


50?


49?


45


50


39


45


2


55?


60?











3








39


54





7


48


81


67


65


57


50


40


49


10


105


125


105


112








11








75


78


45


66


14



150


120









30








50


69


95


71


Retzius also finds in man in the basal turn 25, in the middle 35, and in the apical 23. Thus the angle always increases with age, but has different absolute values in different mammals and always tends to be greater in the middle turns.

15. Lengths of the inner and outer pillar cells. The measurements of length were taken as shown by lines 1-1, and 2-2 as in figure 2. This does not give the total length, but the length from the base to the point, just below the joint. As is well


TABLE 58

Angle of the lamina reticularis with the plane of Ihe membrana basilaris in

degrees, 6 (chart 26}





TURNS OF THE COCHLEA DEGREES


AGE


BODY WEIGHT






I









II


III


IV


Average


days


grams







1


5









3


8









6


11









9


10









12


13


7


12


13


9


10


15


13


11


14


13


13


13


20


29


15


13


11


11


13


25


36


14


14


13


13


14


50


59


15


15


17


11


15


100


112


15


14


16


14


15


150


183


15


15


19


17


17


257


137


13


15


18


17


16


366


181


16


15


16


16


16


546


255


16


16


17


17


17


Vertical averages



13.7


14.3


15.3


13.8



Ratios 12 20 days 1 : 1.3

12546 " :1.7

TABLE 59 Condensed

Ratios of the angle of the lamina reticularis with the plane of the membrana basilaris according to the turns of the cochlea





RATIOS BETWEEN TURNS


AVERAGE AGE


AVERVGE BODY WEIGHT


I-II



I-II I


I- IV


days 12


grams 13


1 1.7


1 1.9


1 : 1.3


18


21


1.0


0.9


0.9


213


138


1.0


1.2


1.0


TABLE 60

Angle of the lamina reticutaris with the plane of the membrana basilaris in degrees

(Retzius)


Age


Basal turn


Middle turn


Apical turn


Average


Basal turn


Middle turn


Apical turn


Average


days










New-born



5?


8?






5? 8?



2














3









5? 8?





7


17


19


11



5


5


10



10


20


30


23


24








11








20


1020





14


25


50


45


40








30








18


23


20


20


GROWTH OF THE INNER EAR OF ALBINO RAT


87


known, the inner and outer pillar cells when mature show a more or less S-shaped curvature, though they are straighter in the earlier stages. Thus the length as measured in the adult cochlea is somewhat smaller than the natural lengths.


DEGREES 18


15


12




25


50


5O 1OO 20O 300 40O 500


Chart 26 The angle subtended by the extension of the lamina relicularis with the extended plane of the membrana basilaris, in degrees, table 58, fieure 1 4-4', 9 In table 61 (charts 27 to 32) is given the values for the lengths of the inner and outer pillar cells according to age. At first we shall consider the average values for the length of the inner and outer pillar cells taken together. This length diminishes at three days. From three to twelve days it increases rapidly,


88


ANATOMICAL AND PHYSIOLOGICAL STUDIES ON


and from twelve to twenty days more slowly. After twenty days it decreases a little. The ratios at the bottom of the last column show these relations. The familiar fact, that the length increases from the base to the apex is clearly shown in chart 28.


TABLE 61


Lengths of the inner and outer pillar cells (without head) measured from the footplate on the membrana basilaris to the point directly below the junction (charts 27 to 32)


AOE


BODY WEIGHT


INNER PILLAR


OUTER PILLAR


Combined Average


Turns of the cochlea M


Turns of the cochlea M


I


II


ill


IV


Average


I


II ill


IV


Average


days


gms













1


5


28


29


29


29


29


24


27


27


26


26


28


3


8


26


23


26


23


25


19


20


20


21


20


23


6


11


35


36


36


37


36


21


26


27


26


25


31


9


10


35


39


41


40


39


26


26


29


29


28


34


12


13


33


38


44


44


40


46


59


72


72


62


51


15


13


34


38


48


51


43


44


59


74


78


64


54


20


29


43


47


56


60


52


56


65


79


83


71


62


25


36


43


47


56


60


52


53


64


80


84


70


61


50


59


42


44


55


61


51


52


64


79


84


70


  • 61


100


112


42


44


53


58


49


52


62


79


84


69


59


150


183


41


43


54


59


49


51


64


76


85


69


59


257


137


40


44


53


60


49


53


64


75


85


69


59


366


181


39


45


53


59


48


50


64


78


83


69


59


546


255


41


44


53


58


49


49


64


78


83


69


59


Ratios 1- 12 days




1 1.4






1 :2.4


1 : 1.8


1- 20 "




1.8






2.7


2.2


1-546 "




1.7






2.7


2.1


20-546 "




0.9






1.0


1.0


When we calculate the average values of the inner and outer pillar cells from Retzius table ('84), we get the following (table 62).

TABLE 62

Combined lengths of the inner and outer pillars from the foot plate to a point directly below the junction in n (Retzius)


RABBIT (adult)


CAT (adult)


MAN (adult)


Basal turn


Middle turn


Apical turn


Average turn


Basal turn


Middle turn


Apical turn


Average


Basal turn


Middle turn


Apical turn


Average


66


85


78


76


55


75


73


67


55


84


87


75



Chart 27 The length of inner and outer pillar cells combined, without head, measured from the foot plate on the membrana basilaris to the point directly below the junction, table 61, figure 2, /-/, 2-2.


Chart 28 The length of inner and outer pillar cells combined, without head, measured from the foot plate on the membrana basilaris to the point directly below the junction, according to the turns of the cochlea, table 61.



Chart 29 The length of inner pillar cell without head, table 61, figure 2, 1-1.


As table 62 shows, the values in these mammals are larger than those in the albino rat a result which fits with our previous observations.

When we consider the length of the inner pillar cells alone, we see that the values (chart 29) here also increases from three days to twenty days, but not so largely as in the combined values of the inner and outer pillar cells. After twenty days the values for the inner pillar cells decrease slightly. This relation is shown by the ratios at the bottom of the corresponding column. That the increase progresses from the base to the apex, being most marked in turn III, is illustrated in chart 30. The condensed table 63 shows those relations also. The one-day-old rat is an exception.

We turn now to the growth in the length of the outer pillar cells. As we see in table 61 (chart 31), the length of the outer pillar cell does not increase so much from one to nine days as the inner pillar cell did. At twelve days, however, the increase in length is very marked, that is, 2.2 times as much as at nine days.

After the outer pillar cell reaches its maximum at twenty days, it decreases only slightly with advancing age. The ratios at the bottom of the corresponding column show this relation clearly. The length increases from base to apex, though this relation is not well established until twelve days, as shown in table 61 and chart 32. The ratios of the outer pillar cells according to the turns of the cochlea are shown in table 64.

The inner and outer pillar cells show marked differences in their growth. While at the earlier ages the length of the inner is greater than that of the outer, yet after twelve days this relation is reversed. Moreover, from nine to twelve days the growth is gradual in the inner pillar cells, but rapid in the outer. The condensed table 65 shows the values for the length of the inner and outer pillar cells separately. In the last column are given the ratios between them.

In the accompanying table 66 I have compared the values obtained in the rat with those given by other authors.

As table 66 shows, the absolute values differ in various animals. However, the ratios between the values for the inner and outer



Chart 30 The length of the inner pillar cell without head, according to the turns of the cochlea, table 61.


Chart 31 The length of outer pillar cells without head, table 61, figure 2,



Chart 32 The length of outer pillar cells without head, according to the turns of the cochlea, table 61.


TABLE 63 Condensed Ratios of the length of the inner pillar cells according to the turns of the cochlea


AVERAGE AGE


AVERAGE BOOT WEIGHT


RATIOS BETWEEN TURNS


I-II


I-II I


I-IV


days 1


grams 5


1 1.0


1 1.0


1 1.0


8


11


1.1


1.2


1.1


18


21


1.1


1.3


1.4


213


138


1.1


1.3


1.4


TABLE 64 Condensed Ratios of the length of the outer pillar cells according to the turns of the cochlea


AVERAGE AGE


AVERAGE BODY WEIGHT


RATIOS


BETWEEN TURNS





I-II


I-II I


I- IV


days 1


grams 5


1 : 1.1


1 1.1


1 1.0


8


11


1.2


1.3


1.3


18


21


1.2


1.5


1.6


213


138


1.3


1.5


1.6


TABLE 65 Condensed

Comparison of the average length of the inner and outer pillar-cellswithout

head.




AVERAGE LENGTH OF PILLAR CELLS



AVERAGE AGE


AVERAGE BODY


WITHOUT HEAD


RATIOS OF INNER



\V V T ( ' H T



TO OUTER




Inner


Outer



days


grams





1


5


29


26


1 :1.0


8


11


35


34


1.0


18


21


48


68


1.4


213


13S


50


69.


1.4


pillar cells are smallest in man and in the rat and alike in the other two forms, Retzius ('84). Hensen ('63) states that in the base of the human cochlea both pillar cells are equally long. Later, Pritchard ('78) supported this observation. In the literature, however, no one except these two authors report the inner and outer pillar cells in the base of the adult cochlea as equal in length, but the inner is always stated to be shorter than the outer. We may therefore say that most authors agree that the inner pillar cells are at earlier stages longer than the outer, then they become equal, and finally the outer surpass the inner.



TABLE 66

Lengths of inner and outer pillars in several mammals according to different authors.

Measurements in n


INNER PILLAR


OUTER PILLAR


Authors


Animals


Basal turn


Middle


Apical



Av.


B.


M.


A.



Av.


Ratio


Corti


Mammals


30


30


34


31


4549


54 58


69


57


1:1.8


Hensen


Man


48



86 (Hamul us)


48




98 (Hamulus)



Ret zius

Wada


Rabbit


56


60


60


59


75


110


95


93


l.


Cat


41


54


57


51


68 62


95


89


84


1.6


Man


48


68


70


62


100


103


88


l.t


Albino rat after 20 days


I 41


II 45


III

54


IV

59


50


I 52


II 64


III

78


IV

84


70


-.1.4


16. Inner and outer hair cells. For a long time the inner and the outer hair cells have been regarded as the most important elements in the papilla spiralis. As these sense cells have a delicate histological structure which is readily altered, the systematic study of their growth, especially after the appearance of hearing, is a difficult matter. Though there are some observations on the length of these cells, detailed studies on their growth have not been made heretofore. I have therefore endeavored to follow the changes of their size during the postnatal period. It is first necessary to determine the form of these cells. They are generally described as cylindrical, but this description is inexact. Moreover, the inner and outer hair cells are somewhat different in shape. The former has on the surface a large oval terminal disk, which is wide hi the spiral and narrow in the radial direction. This narrows downwards to a thinner neck which expands into the broader body and terminates in a more or less round but somewhat pointed irregular end.


94



Chart 33 The weighted volume of inner and outer hair cells combined, and of their nuclei in cubic micra, tables 67 and 69.

- Weighted volume of inner and outer hair cells combined. Weighted volume of nuclei of inner and outer hair cells combined.

The outer hair cells have a much more cylindrical form, their upper terminal disk is not so wide and not round, but hexagonal. They become a bit thin in the neck, then wide in the body. Their lower end is rounded. In order, however, to determine the cell volume, the cell form has been taken as that of a cylinder. For computation, the average of the diameters measured in three places, the end disk, neck, and cell body, was taken as the diameter and the length of the cell as the length of the cylinder. From these data the volume of the cylinder was computed.



In table 67 are given the values for the volume of the cell bodies in the (1) inner and (3) outer hair cells separately and the weighted volume of both cells (in the radial section of the rat cochlea we see one row of inner and three rows of outer hair cells), according to age.

TABLE 67

Average volumes of the inner and outer hair cells in cubic micro (charts 33 to 37)


AGE



INNER HAIR CELL


OUTER HAIR CELL



BODY WGHt


Tu

I


rns of II


the o III


achlea IV


fit Average


T I


urns o II


f the ( III


iwlilr;

IV


l M 3 Average


WEIOHTD AVERAGE VOLUME


days 1


gms 5


1255


982


832


631


925


641


626


505


359


533


631


3 6 ' 9 12 15 20


8 11 10 13 13 29


1457 1374 1451 1553 1598 1627


1367 1451 1734 1812 1618 1764


1206 1549 1994 1910 1902 1972


913 1221 2013 2157 2128 2189


1236 1399 1798 1858 1812 1888


767 1047 914 818 815 894


928 967 1308 1210 1178 1215


867 1053 1459 1602 1595 1606


571 800 14^8 1499 1559 1960


783 967 1277 1282 1287 1419


896 1075 1407 1426 1418 1536 1293


Av. 11


14


1510


1624


1756


1770


1665


876


1134


1364


1303


1169


25 50 100 150 257 366 546


36 59 112 183 137 181 255


1540 1497 1353 1362 1345 1290 1266


1655 1611 1550 1497 1524 1561 1486


1909 1821 1744 1683 1738 1817 1772


1995 1924 2018 1917 1976 2297 2257


1775 1713 1666 1615 1646 1741 1695


834 805 837 832 873 893 831


1243 1204 1306 1150 1230 1239 1336


1539 1580 1510 1803 1555 1651 1650


1702 1906 1737 1917 1927 1844 1839


1330 1374 1348 1426 1396 1407 1414


1441 1459 1428 1473 1459 1491 1484


Av. 213


138


1379


1555


1783


2055


1693


844


1244


1613


1839


1385


1462


Ratios 1- 12 days 1- 20 " 1-546 " 20-546 " 1- 11 " 11-213 "


1 :2.0

2.0

0^9



1 :2.4

2.7
2.7
2!2


1 :2.3

2.4
2.4
0.9
2.0


At first we shall consider the weighted volume for the cell bodies of the inner and outer hair cells combined (chart 33). As table 67 shows, the volume increases continuously to the full size at twenty days. From one to twelve days the increase is rapid, and after that the volumes are about the same, though somewhat fluctuating. The ratios show this relation clearly.


Condensing all age groups into three (averages in table -67), then the relation changes somewhat. From one to eleven days the volume increases more than 100 per cent, while from eleven to 213 days it increases only 13 per cent.


Chart 34 The volume of inner hair cells and of their nuclei, tables 67 and 69.

Volume of inner hair cells. Volume of nuclei of inner hair cells.

The data for the growth of the nuclei of the inner and outer hair cells are presented in tables 68 and 69. The weighted values for the diameters of the nuclei (table 68) are large at the earlier stages, but from twelve days decrease gradually till old age. In the three condensed age groups (averages) we see the decrease of the values from birth till old age. In table 69 are given the values for the volumes of the nuclei, calculated as spheres (chart 33).


Chart 35 The volume of inner hair cells, according to the turns of the cochlea, table 67.


The weighted values for the volumes of the inner and outer hair cells in each turn are given in [A 3 table 70. At the bottom of each column is given the ratio from 1 to 12, 1 to 20, 1 to 546, and 20 to 546 days of age. While the volume at birth is largest in turn I and smallest in turn IV, that in turn III is largest at


Chart 36 The volume of outer hair cells and of their nuclei, in cubic micra, tables 67 and 69.

Volume of outer hair cells.

._. Volume of nuclei of outer hair cells.

six days. After nine days the volume increases always from base to apex.

Comparing the weighted vo'ume in each turn according to age, we find that the rate of increase in volume is smallest in turn I (1.3 to 1.2) and largest in turn IV (3.9 to 4.6) (table 70).

In table 72 are given the weighted values for the diameters of the nuclei of the inner and outer hair cells in each turn. They increase and then decrease during the first twelve days. The rate of decrease is largest in turn I, and smallest in turn IV, as the ratios at the bottom of each column show. That the diameters at


Chart 37 The volume of outer hair cells, according to the turns of the cochlea, table 67.

the later ages have about the same value in each turn, or are a little larger in the upper than in the lower turn, is to be seen in table 73.


TABLE 68 Mean diameters of the nuclei of the inner and outer hair cells in M




DIAMETERS NUCLEI OF THE


DIAMETERS NUCLEI OF THE


INNER HAIR CELLS


OUTER HAIR CELLS


WEIGHT

AGE


BODY

wght


Turns of the cochlea ju


Turns of the cochlea M


ED AVERAGE




I


II


ill


IV


Average


I


II


ill


IV


Average



days


gms.


1


5


8.6


8.3


7.8


7.8


8.1


7.7


8.1


7.4


7.6


7.7


7.8


3


8


8.6


8.5


8.2


7.8


8.3


8.3


8.4


8.J


7.5


8.1


8.2


6


11


8.5


8.6


8.3


8.0


8.3


8.0


8.0


8.1


7.9


8.0


8.1


c


10


8.7


8.5


8.2


8.7


8.5


76


7.9


8.4


8.2


8.0


8.1


12


13


7.6


7.7


7.5


7.9


7.7


5.8


6.5


6.8


7.4


6.6


6.9


15


13


7.5


7.5


7.7


7.9


7.6


6 1


6.6


6.8


7.0


6.6


6.9


20


29


7.0


7.3


7.6


7.8


7.4


6.0


6.4


6.9


7.3


6.6


6.8


Av. 11


14


8.0


8.0


7.9


8.0


8.0


7.0


7.3


7.5


7.6


7.3


7.5


25


36


7.3


7 2


7.2


7.1


7.2


6.0


6.3


6.3


6.5


6.3


6.5


50


59


7.0


75


7.3


7.3


7.3


6.0


6.2


6.3


6.7


6.3


6.6


100


112


6.7


7.0


7.1


7 1


7.0


5.8


6.0


6.0


6.0


5.9


6.2


150


183


6.6


6.8


7.0


7.3


6.9


6.0


6.0


6.2


6.1


6.0


6.2


257


137


6.6


6.9


7.0


7.7


7.0


5.9 16.0


6.2


6.4


6.1


6.3


366


181


7.6


7.4


7.3


7.2


7.4


5.9


6.0


6.1


6.0


6.0


6.4


546


255


6.5


6.5


6.5


7.1


6.6


5.8


6.0


6.1


6.4


6.1


62


Av. 213! 138


6.9


7.0


71


7.3


7.1


5.9


6.1


6.2


6.3


6.1


6.3


Ratios 1- 12 days


1:1. 0,|


1 :0.9|| 1 :0.9


1- 20 "


0.9


0.9 :0.9


1-546 "


0.8



O.S 0.8


20-546 "


0.9 |


0.9 :0.9


TABLE 69 Average volumes of the nuclei of the inner and outer hair cells (charts 33, 34 and 36)


AGE


BODY WEIGHT


VOLUME OF NUCLEUS HAIR CELLS

Inner Outer


WEIGHTED VOLUMES INNER AND OUTER HAIR CELLS


days


gms.


M'


M


M 3


1


5


278


239


248


3


8


299


278


289


6


11


299


268


278


9


10


322


268


278


12


13


239


151


172


15


13


230


151


172


20


29


212


151


165


25


36


195


131


144


50


59


204


131


151


100


112


180


108


125


150


183


172


113


125


257


137


180


119


131


366


181


212


113


137


546


255


151


119


125


Ratios 1- 12 days 1- 20 " 1-546 " 20-546 "


1 :0.9

0.8
0.5
0.7


0.6
0.6
0.5
0.8


0.7
0.7
0.5
0.8


100


GROWTH OF THE INNER EAR OF ALBINO RAT


101


The growth of the inner hair cell. The volume of the inner hair cell table 67 (chart 34) increases with age up to twenty

TABLE 70

Weighted volumes of the inner and outer hair cells according to the turns of the

cochlea


AGE


BODY WEIGHT


TURNS OF THE COCHLEA M*


I


II


ill


IV


days


gms.






1


5


795


715


587


427


3


8


940


1038


952


657


6


11


1129


1088


1177


905


9


10


1048


1415


1593


1574


12


13


1002


1361


1679


1664


15


13


1011


1288


1672


1701


20


29


1052


1352


1698


2017


25


36


1011


1346


1632


1775


50


59


978


1306


1640


1911


100


112


966


1367


'1569


1807


150


183


965


1237


1773


1917


257


137


991


1304


1601


1939


366


181


992


1320


1693


1957


546


255


940


1374


1681


1944


Ratios 1- 12 days


1 : 1.3 1


1.9


1 :2.9


1 :3 9


1- 20 "


1.3


1.9


2.9


4.7


1-546 "


1.2


1.9


2.9


4.6


20-546 "


0.9


1.0


1.0


1.0


TABLE 71 Condensed

Ratios of the weighted volumes of the inner -and outer hair cells according to the turns

of the cochlea




BATI08 BETWEEN TURNS


AGE


BODY WEIGHT


I-II


i-ni


I-IV


days


0ms.





1


5


1 :0.9


1 :0.7


1 :0.5


8


11


1.2


1.3


1.2


18


21


1.3


1.6


1.8


213


138


1.4


1.7


1.9


days; to nine days rapidly, then slowly. After twenty days it decreases slowly, as do the weighted volumes of the inner and outer hair cells, and with fluctuations, is nearly the same after


102


ANATOMICAL AND PHYSIOLOGICAL STUDIES ON


100 days. The three condensed age groups show that from 1 to 11 days it has increased 80 per cent, while from 11 to 213 days it has gained less than 2 per cent.

TABLE 72

Weighted diameters of the nuclei of the inner and outer hair cells according to the

turns of the cochlea


AGE


BODY WEIGHT


TURNS OF THE COCHLEA M


I


II


ill


IV


days


gms.






1


5


7.9


8.2


7.5


7.7


3


8


8.4


8.4


8.1


7.6


6


11


8.1


8.2


8.2


7.9


9


10


7.9


8.1


8.4


8.3


12


13


6.3


6.8


7.0


7.5


15


13


6.5


6.8


7.0


7.2


20


29


6.3


6.6


7.1


7.4


25


36


6.3


6.5


6.5


6.7


50


59


6.3


6.5


6.6


6.9


100


112


6.0


6.3


6.3


6.3


150


183


6.2


6.2


6.4


6.4


257


137


6.1


6.2


6.4


6.7


366


181


6.3


6.4


6.4


6.3


546


255


6.0


6.1


6.2


6.6


Ratios 1- 12 days


1 :0.8


1 :0.8


1 :0.9 1


1.0


1- 20 "


0.8


0.8


0.9


1.0


1-546 "


0.8


0.7


0.8


0.9


20-546 "


1.0


0.9


0.9


0.9


TABLE 73. Condensed

Ratios of the weighted diameters of the nuclei of the inner and outer hair cells according to the turns of the cochlea




RATIOS BETWEEN TURNS


AVERAGE AGE


AVERAGE BODY




WEIGHT







I-II


i-m


I-IV


days


gms.





1


5


1 :1.0


1 0.9


1 1.0


8


11


1.0


1.0


1.0


18


21


1.0


1.1


1.1


213


138


1.0


1.0


1.1


From nine days on the volume of the inner hair cell increases in passing from the base to the apex. During the earlier stages


GROWTH OF THE INNER EAR OF ALBINO RAT


103


there are some fluctuations (table 67, chart 35). In the condensed table 74 the general relations are shown. The growth of the nuclei of the inner hair cells in diameter is given in table 68. As we see, the diameters increase from birth to nine days, then decrease slowly but steadily. In the three average age groups, however, the values decrease continuously with age. In table 69 are given the values for the volumes of the nuclei of the inner hair cell (chart 34).

TABLE 74 Condensed Ratios of the volume of the inner hair cells according to the turns of the cochlea

RATIOS BETWEEN TURNS


AVERAGE AGE


AVERAGE BODY




WEIGHT



I-II


i-in


I-IV


days


grams





1


5


1 0.8


1 0.7


1 0.5


11


14


1.1


1.2


1.2


213


138


1.1


1.3


1.5


TABLE 75 Condensed

Ratios of the diameters of the nuclei of the inner hair cells according to the turns of the cochlea


RATIOS BETWEEN TDRN8


AVERAGE AGE


AVERAGE BODY




WEIGHT







I-II


I-II I


I-IV


days


grams





1


5


1 1.0


1 :0.9


1 0.9


11


14


1.0


1.0


1.0


213


138


1.0


1.0


1.1


The ratios of the diameters of the nuclei of the inner hair cells decrease at the earlier ages in each turn from the base to the apex. After nine days they are nearly the same in all the turns (tables 68 and 75), though their absolute values decrease in all the turns after nine days.

The growth of the outer hair cells. In general, the changes in the volume of the outer hair cells are like those in the inner hair cells. Therefore, the volume increases strikingly up to nine days of age, then gradually to twenty days. The main difference is that the volume in the outer hair cells does not diminish so much after twenty-five days, but holds nearly the same value (table 67, chart 36). In condensed age groups, therefore, we see a large increase in the size of the cells with age.

To determine the growth of the outer hair cells in each turn of the cochlea, table 67 is used (chart 37). From twenty days on the values increase from the basal to the apical turn. Before twenty days the relations are irregular or reversed. In table 76 this relation is clearly brought out.

Comparing the changes of the volume of the outer hair cells in three age groups (table 67), we find that the average volume increases throughout each turn with age, except in turn I, where


TABLE 76 Condensed Ratios of the volumes of the outer hair cells according to the turns of the cochlea


RATIOS BETWEEN TURNS


AVERAGE AGE


AVERAGE BODY




WEIGHT


I-II


i-in


I-IV


days


grams





1


5


1 1.0


1 0.8


1 0.6


11


14


1.3


1.6


1.5


213


138


1.5


1.9


2.2


that at eleven days is largest. In the inner hair cells, however, values at eleven days are largest in both turn I and II.

For the nuclei of the outer hair cells, the diameters are given in table 68). Here the d ! ameters tend to increase from one to nine days. At twelve days they decrease strikingly, and after that very slowly. In table 69 are given the values for the volumes of the nuclei of the outer hair cells.

In table 68 are given also the measurements for the nuclei of the outer hair cells according to the turn of the cochlea. At nine days and after, the diameters become larger in passing from base to apex, while in the earlier stages this relation is irregular or reversed. The decrease of the measurements in, each turn with age is clearly shown in the three age groups.


In table 77 are given the average ratios of turn I to the three other turns.

The comparison of the growth of the inner and outer hair cells. As already stated, the growth of the inner and outer hair .cells in volume proceeds in about the same way till they reach their full size at twenty days. After that we note a difference between them. While the outer hair cells maintain a nearly constant volume, the volume of the inner hair cells diminishes

TABLE 77 Condensed

Ratios of the diameters of the nuclei of the outer hair cells according to the turns of

the cochlea




RATIOS BETWEEN TURNS


AVERAGE AGE


AVERAGE BODY




WEIGHT







I-II


I-II I


I-IV


days


grams





1


5


1 1.1


1 1.0


1 1.0


11


14


1.0


1.1


1.1


213


138


1.0


1.1


1.1


TABLE 78 Condensed Comparison of the volumes of ike inner and the outer hair cells




AVERAGE VOLUMES HAIR CELLS



AVERAGE AGE


AVERAGE BODY



RATIOS OF INNER



WEIGHT




TO OUTER




Inner


Outer



days


grams


M


A



1


5


925


533


1 0.6


11


14


1665


1169


0.7


213


138


1693


1385


0.8


somewhat with age. When we consider the volume according to the three age groups, it increases in both groups throughout life (table 78). There are, however, large differences in the rate of increase. The inner hair cell increases its volume at 11 days by 80 per cent and between 11 and 213 days by less than 2 per cent. For the outer hair cells the increase by 11 days is 120 per cent and from 11 to 213 days, 19 per cent. At the same time the inner are always larger than the outer hair cells, as the ratios in table 78 show.


The diameters of the nuclei in both the inner and outer hair cells diminish in value after nine days of age. This decrease is larger in the outer than in the inner cells. In table 79 are given the values for the diameters of the nuclei in both inner and outer hah* cells. In the last column are the ratios between them.

Thus, while the volumes of the outer hair cells, as compared with the inner hair cells, become relatively larger with age (table 78), the diameters of their nuclei become relatively smaller (table 79).

TABLE 79 Condensed Comparison of the diameters of the nuclei of the inner and outer hair cells




AVERAGE DIAMETERS OF THE


AVERAGE


NUCLEI OF THE HAIR CELLS


RATIOS OF THE AVERAGE DIAMETERS OF THE NUCLEI OP


AVERAGE AGE


BODY






WEIGHT


Inner


Outer


CELLS


days


grams


M


M




1


5


8.1


7.7


1 1.0



11


14


8.0


7.3


0.9



213


138


7.1


6.1


0.9



Comparison of the growth of the inner and outer hair cells according to sex. A careful and elaborate comparison has been made to determine whether there are differences in the growth of the hair cells according to sex.

In table 80 are given the average values for the volumes of the cell bodies and their respective nuclei. No significant differences according to sex were found.

Comparison of the growth of the inner and outer hair cells according to side. The same treatment of the data was followed as in the determination for the influence of sex. In table 81 are given the average values for the volumes of the inner and outer hair cells and their respective nuclei. Again no significant differences according to side were found.

On the nucleus-plasma ratios of the inner and outer hair cells. For the inner and outer hair cells here measured the weighted volumes of the cell bodies and of their nuclei are entered in the condensed table 82, and the ratios of the volume of the nucleus to that of the cytoplasm (=cell volume less nucleus volume) are given in the last column. This ratio increases with age, as table 82 shows. While the ratio is 1.5 in the youngest and smallest group, it is 9.9 in the largest. This means that as a group these cells are continually growing in volume. This result may be analysed for the two groups of cells involved.

TABLE 80

Average volumes of inner and outer hair cells and of their respective nuclei

in n 3 according to sex



INNER HAIR CELLS


OUTER HAIH CELLS


WEIGHTED AVERAGE


Att


BODY


NO. OF


BEX


Average volume


Average volume


VOLUME




BATS


Cell


Nucleus


Cell


Nucleus


CELLS


NUCLEI


da j/5


grams










3


7


1


0*


1213


310


815


268


915


278



8


1


9


1319


310


888


322


996


319


6


11


2


tf


1426


289


955


278


1073


281



10


2


9


1372


310


979


268


1077


278


9


10


2


cT


1701


310


1351


258


1439


271



9


2


9


1895


345


1203


278


1376


295


12


14


2


c? 1


1830


258


1344


157


1466


182



12


2


9


1886


221


1221


151


1387


168


100


146


1


cT


1687


180


1342


113


1428


129



103


1


9


1779


212


1319


108


1434


184


150


189


1


rf 1


1679


165


1382


119


1456


131



154


1


9


1639


212


1611


119


1618


142


365


205


1


tf


1739


258


1389


119


1477


154



170


1


9


1659


221


1486


113


1529


140


Volume greater in male 3


2


3


4


5


3


Volume greater in female 4


4


4


2


2


4


Equal


1



1



.


The nucleus-plasma ratio of the inner and outer hair cells considered separately. This is shown for the inner hair cells in table 83. The ratios are also progressive, but somewhat larger for the earlier age groups and smaller for the oldest, than in the previous instance.

The ratios for the outer hair cells are also progressive, and the range is greater than for the inner hair cells as table 84 shows. Here the ratio is 1.2 for the youngest group and 10.6 for the oldest. This indicates that at one day and eleven days the relative volume is less in the outer than in the inner hair cells, but at the later age the outer hairs cells grow more.


TABLE 81


Volumes of the inner and outer hair cells and of their respective nuclei according

to side in ft 3


AGE


BODY WEIGHT


NO. OF

BATS


SIDE


INNER HAIR CELLS


OXJTER HAIR CELLS


WEIGHTED AVERAGE VOLUME


Average volume


Average volume


Cell


Nucleus


Cell


Nucleus


CELLS


NUCLEI


1


5


2


R.


895


299


555


248


640


261





L.


955


268


511


230


622


239


3


7


1


R.


1213


310


815


268


915


278





L.


1395


299


920


299


1039


299


6


11


2


R.


1381


322


1010


278


1103


289





L.


1416


289


923


258


1046


268


9


9


2


R.


1782


310


1177


268


1328


278





L.


1815


333


1378


268


1487


284


12


12


1


R.


1887


212


1310


151


1454


166





L.


1885


221


1132


151


1320


168


15


13


1


R.


1895


230


1522


144


1615


165





L.


1848


239


1419


151


1526


172


20


29


2


R.


1914


212


1365


144


1502


161





L.


1862


221


1472


165


1570


179


25


36


2


R.


1758


204


1307


131


1420


149





L.


1792


195


1351


131


1461


147


50


59


2


R.


1741


204


1443


125


1518


145





L.


1687


204


1305


137


1401


154


100


102


2


R.


1675


187


1355


113


1440


131



123


2


L.


1658


172


1339


113


1419


128


150


189


1


R.


1565


172


1420


113


1456


128





L.


1679


165


1382


119


1456


131


257


137


2


R.


1685


187


1377


125


1454


140





L.


1607


180


1416


119


1464


134


367


175


2


R.


1634


195


1436


113


1486


134


365


188


2


L.


1848


230


1374


113


1493


142


546


255


2


R.


1831


157


1474


119


1563


128





L.


1559


151


1353


119


1405


127


Volume greater on right side 7


8


9


3


7


6


Volumfe greater on left side 7


5


5


5


6


8


Equal


1



6


1




GROWTH OF THE INNER EAR OF ALBINO RAT


109


This seems to be important and to illustrate the fact that in the papilla spiralis the growth of the elements lying nearer the axis occurs earlier than that of the elements nearer the periphery.

TABLE 82 Condensed Nucleus-plasma ratios of the inner and outer hair cells M*


AVERAGE AGE


AVERAGE BODY WEIGHT


AVERAGE VOLUME OF INNER AND OUTER HAIR CELLS


VOLUME OK CYTOPLASM


NUCLEUSFLA8MA RATIOS


Cell


Nucleus


days

1

11

213


grams 5 14 138


631 1293 1462


248 226 134


383 1067 1328


1 : 1.5

4.7:9.9


TABLE 83 Condensed Nucleus-plasma ratios of the inner hair cells /**


AVERAGE AGE


AVERAGE BODY WEIGHT


AVERAGE VOLUME OF 1XXER HAIR CELLS


VOLUME

or

CYTOPLASM


NUCLEUSPLASMA RATIOS


Cell


Nucleus


days 1 11 213


0ms.

5

14 138


925 1665 1693


278 268 187


647

1397 1506


1 2.3 5.2 8.1


TABLE 84 Condensed Nude us- plasma ratios of the outer hair cells


AVERAGE AGE


AVERAGE BODY WEIGHT


AVERAGE VOLUME OF OUTER HAIR CELLS


VOLUME or

CYTOPLASM


NUCLEUSPLASMA RATIOS


Cell


Nucleus


days 1 11 213


grams 5 14 138


533 1169 1385


239 204 119


294

965 1266


1 1.2

4.7 10.6


17. Deiters' cells. The Deiters' cells are most delicate elements. In the literature, so far as I know, there are no exact observations touching the growth of these cells in the papilla spiralis, except a few data for their length. They have an


110 ANATOMICAL AND PHYSIOLOGICAL STUDIES ON

irregular form and consist of three parts, the phalangeal process, cell body, and foot. The phalangeal process is thin, somewhat crooked in the adult though it runs straight at an earlier stage. As the boundary between this process and the cell body, we take a line running through the supporting cup ('Stutzkelch' of Held) parallel to the plane of the basilar membrane (fig. 10). The cell body in its upper part is wide, including here a round nucleus. It then becomes thin and passes over to the foot. Thus it is almost impossible to get the true volume of the cells. Therefore, we have determined the volume of the cell body only, excluding that of the phalangeal process.

We think of the cell body as a cylinder having an average diameter, which is calculated from four diameters measured at four levels. The first level is just below the upper boundary of the cell body, the second in the widest part, the third below at about the middle of the cell body, and the last is at the narrowest part near the foot. .

The height of the cylinder is the length of the cell body within the limits just noted. Thus the volume obtained approximates the value for the natural size of the cell body without the process.

In table 85 (chart 38) are given the values for the volumes of the Deiters' cells thus computed and the diameters and volumes of the nuclei according to age. As there are in the radial section three rows of cells, the values given are, of course, the average of these. At the bottom of the last column appear the ratios at 1 to 12, 1 to 20, 1 to 546, and 12 to 546 days. As we see, the volume of the cell body increases throughout life, slowly during the first nine days, but from twelve to twenty days very rapidly, and then less rapidly to old age.

While the ratio from one to twelve days is 1:5.4, that from 1 to 546 days is 1:29.1, or more than five times as large.

When we consider the volumes of the cells in each turn of the cochlea, we see that it is smallest in turn I and largest in turn IV, though there are some exceptions before nine days of age. Table 86 shows these relations.

The diameters of the nuclei of the cells grow, after some fluctuations in the values at earlier stages, very slowly to old


GROWTH OF THE INNER EAR OF ALBINO RAT 111

age, as indicated in table 85 and chart 38. The ratios at the bottom of the corresponding column show these relations. The values for the volumes of the nuclei of the cells are given in the last column. Here, also, the diameters in the upper turns tend to be larger than in the basal turn. In table 87 are given the ratios of the diameters of turn I to the three other turns. We see in all the turns about the same ratios, 1:1.0.

In the literature we find but two observations on the diameters of the nuclei of the Dieters' cells. Kolmer ('07) reports hi the pig 5 [i, and von Ebner ( '02) gives in man 7 (x for the diameter of the round nucleus of the cells.

In the rat, therefore, the diameter is larger than in these two forms, but no significance can be attached to this difference until correction has been made for the several techniques employed. This I am unable at present to do.

On the nucleus-plasma ratio in Deiters 1 cells. In the condensed table 88 are given the volumes of the cell bodies and of their nuclei together with the respective nucleus-plasma ratios. This shows that the ratio is progressive with age. While the ratio is at birth only 0.05, that in the oldest group is 28.3. The absolute increase is not great at earlier stages, but by eighteen days it is marked

The rapid change in the ratio is very interesting. Before eight days of age the cells are still immature. Some time after eight days they develop rapidly, seeming to play some important part in the special functions of the cochlea.

On the length of Deiters' cells. To measure the length of Deiters' cells we divide them into two parts, the upper and the lower, by the boundary line between the cell body and the phalangeal process. The sum of these two lengths makes the total length of the cells.

In table 89 are given the values for the total length and for each part separately (chart 39). As in the volume of the cells, we see an astonishing change in the development of the length. The length of the cells increases through life, at earlier stages a little, but at twelve days it becomes nearly twice as long as at nine days. The ratios at the bottom of the last column show the course of growth.


TABLE 85

The volume of Deiters' cells and the mean diameters and volumes of their respective nuclei (chart 38)


VOLUME OF THE DEITERS* CELLS


1

NUCLEI


VOLUMES



BODY


fit


Diameters



AGE


WEIGHT



Average





I


II


III


IV


Average


I


II


III


IV


diam

Average








volume






eters


volumes













M


M


days


grams













1


5


278


232


237


256


251


7.6


7.5


7.5


8.1


7.7


239


3


8


290


309


349


352


325


7.0


7.0


6.9


7.0


7.0


180


6


11


425


395


495


364


420


7.0


6.5


6.7


6.6


6.7


165


9


10


635


461


554 423


518


6.9


7.0


7.1


7.1


7.0


180


12


13


1122


1369 1395


1569


1364


6.5


7.0


6.9


7.1


6.9


180


15


13


1466


2187 2659


3127


2359


7.0


7.2


7.2


7.3


7.2


195


20


29


3576


427115740


6171


4939


7.6


7.8


7.9


7.9


7.8


248


25 50


36 59


4088 4467 5470 4839 5970 6258


5757 6816


4695 5971


7.3 7.3


7.2 7.5


7.3

7.5


7.4 7.4


7.3 7.4


212 212


100


112


5011


6083


7137 6607


6210


6.9


7.6


7.5


7.4


7.3


212


150


183


5755 6291 7657


6750


6613


7.5


7.6


7.5


7.1


7.4


212


257


137


5776 6540 8841


8544


7425


7.4


7.8


7.9


8.0


7.8


248


366


181


6163


6908


7701


7895


7167


7.4


7.7


7.9


7.9


7.7


248


546


255


6092 6919 8028


8152


7298


7.4


7.9


8.0


7.7


7.7


248


Ratios 1 12 days


1 5.4






1 0.9



1 20 "


19.7






1.0



1546 "


29.1






1.0



12546 "


5.4

!






1.1



TABLE 86 Condensed Ratios of volumes of the Deiter's cells according to turns of the cochlea




RATIOS BETWEEN TURNS


AVERAGE AGE


AVERAGE BODY




WEIGHT


I-II


i-m


I-IV


days


grams





1


5


1 :0.8


1 :0.9


1 :0.9


8


11


1.0


1.1


1.1


18


21


1.3


1.7


1.8


213


138


1.1


1.4


1.3


TABLE 87 Condensed Ratios of the diameters of the nuclei of Deilers' cells according to turns of the cochlea




RATIOS BETWEEN TURNS


AVERAGE AGE


AVERAGE BODY




WEIGHT






I-II


I-III


I-IV


days


grams





1


5


1 1.0


1 1.0


1 : 1.1


8


11


1.0


1.0


1.0


18


21


1.0


1.0


1.0


213


138


1.0


1.1


1.0


112


GROWTH OF THE INNER EAR OF ALBINO RAT


113


90OO


8OOO


7OOO


6000


5000


4000


3OOO


2OOO


1OOO




AGE


o


25


50


50 1OO 2OO 300 4OO 5OO


Chart 38 Showing the volume of Deiters' cells and their nuclei, on the average and according to the turns of the cochlea, table 85. Average volume of Deiters' cells.

._. Volume of the cells in about the middle of the basal turn.

Volume of the cells in about the beginning of the middle turn.

Volume of the cells in about the middle of the middle turn.

Volume of the cells in about the beginning of the apical turn.

Average volume of nuclei of Deiters' cells, X 10.



Comparing the length of the cells according to the turn of the cochlea, we find that after twelve days the length increases from the base to the apex, in turn III very rapidly, in turn IV gradually (table 90). At earlier stages the relations are irregular.


TABLE 88 Condensed Nucleus-plasma ratios of the Deiters' cells




AVERAGE VOLUMES







VOLUME OF


NUCLEUS

AVERAGE AGE


AVERAGE BODY




CYTOPLASM


PLASMA RATIOS



WEIGHT


Cell


Nucleus


.M





M


M




days


grams






1


5


251


239


12


1 : 0.05


8


11


657


172


485


2.8


18


21


3649


221


3428


15.5


213


138


6483


221


6262


28.3


TABLE 89

Length of cell body and of processus phalangeus of Deiters' cells p (chart 39)




LENGTH OF THE CELL BODY


LENGTH OF THE PROCESSUS






PHALANGEUS







TOTAL



BODY




LENGTH


AGE


WEIGHT


Turns of cochlea


Turns of cochlea


OF THE






CELLS




I


II


III


IV


Average


I


II


ill


IV


Average



days


gms













1


5


8


8


8


9


8


20


19


20


15


19


27


3


8


8


9


9


10


9


16


17


18


18


17


26


6


11


9


9


11


10


10


19


22


23


22


22


32


9


10


18


12


13


11


14


18


21


26


24


22


36


12


13


31


35


40


43


37


18


22


29


25


24


61


15


13


34


37


40


43


39


21


25


32


31


27


66


20


29


39


41


49


49


45


19


23


30


34


27


72


25


36


42


43


51


51


47


17


21


30


32


25


72


50


59


41


45


53


53


48


16


22


30


34


26


74


100


112


43


45


54


53


49


17


25


29


31


26


75


150


183


45


46


53


52


49


17


22


32


34


26


75


257


137


43


46


56


58


51


18


24


28


31


25


76


366


181


43


48


55


55


50


17


23


29


32


25


75


546


255


46


49


56


56


52


16


23


30


33


26


78


Ratios 1 12 days



1 :4.6






1 :1.3


1 :2.3


1 20 "



5.6






1.4


2.7


1546 "



6.5






1.4


2.9


12546 '"



1.4






1.1


1.3


When we consider the length of the cell body, it is remarkable that the increase takes place so rapidly. While at 1 day it measures only 8 (x and at nine days only 14 ji, it increases very suddenly at twelve days of age, and after that slowly but continuously (table 89).

TABLE 90 Total length of Deiters' cells according to turns of the cochlea (chart 39)


AGB


BOOT WEIGHT


TURNS OF THE COCHLEA


I


II


III


IV


days


grams






1


5


28


27


28


24


3


8


24


26


27


28


6


11


28


31


34


32


9


10


36


33


39


35


12


13


49


57


69


68


15


13


55


62


72


74


20


29


58


64


79


S3


25


36


59


64


81


83


50


59


57


67


83


87


100


112


60


70


83


84


150


183 '


62


68


85


86

257


137


61


70


84


89


366


181


60


71


84


87


546


255


62


72


86


89


80 M 60

40

20 n


Chart 39 The length of Deiters' cells, tables 89 and 90.


500


Total length of the cells. Length of the cell bodies. Length of processus phalangeus.


In the ratios at the bottom of table 89 this is shown very evidently and in each turn this relation is to be seen.

For the length of the phalangeal process the story is quite different. It increases from birth to twelve days a little; at fifteen days it reaches full size, and then holds its value (table 89) . After three days the length is smallest in turn I and largest in turn IV. This relation lasts to old age.

Comparing the growth of the length of the cell body and phalangeal process, there is a large difference between them. While the length in the phalangeal process is at birth over twice that of the cell body, at 546 days it is only half that of the cell

TABLE 91

Total length of Deiters' cells in fj, (Retzius)


AGE



RABBIT


CAT



Basal


Middle


Apical


Average


Basal


Middle


Apical


Average



turn




New-born


48


70


60


59


45


65


48


53


2


45


66


54


55






1


3








45


60





7


80


90


75


82


49


69


63


60


10


98


100


114


104








11








75


90


45


70


14


84


105


112


100








30



54


75


70


66


body. Thus the increase of the total length of Deiters' cells is due chiefly to the increase in the length of the cell body.

Retzius ('84) gives the length of Deiters' cells in the rabbit and cat as in table 91.

Table 91 shows that in both the rabbit and the cat the length at all ages is greater, and especially at the earlier stage is twice as great, as in the rat. In the rabbit there is a rapid increase in length between seven and ten days. For the cat the values are smaller, nearer those of the rat, and show less change between birth and thirty days.

18. Summary and discussion. Using the foregoing data on the form and measurements of the elements of the cochlear duct, I desire here to summarize the results and to discuss the consequent changes in the form of the organ of Corti (table 92).


We have already noted that at birth the greater epithelial ridge constitutes the main part of the tympanic wall, and the lesser epithelial ridge, from which arises later the most important organ, is represented by a small and undeveloped prominence. With age this greater ridge disappears gradually and is transformed into a furrow lined with low epithelial cells, the sulcus spiralis internus (Waldeyer). These changes appear first at the base and then pass gradually to the upper turns. In the lesser ridge also there are important developmental changes. At first the hair cells and pillar cells grow, and just before the special function appears, striking changes are seen in Deiters' and Hensen's cells. These increase, especially in their length, very rapidly.

Thus the papilla spiralis, which hitherto had its highest point at the summit of the arch of Corti, shows a remarkable change of form, as the outer part of the papilla increases its height, so that finally Hensen's cells mark the highest point in the papilla. The surface then ceases to be parallel to the basilar membrane, and slopes inward, making with the basilar membrane an acute angle opening outward. At the same time the papilla spiralis appears to be shifted inward i.e., towards the axis.

Kolliker has described how the cells, from which the pillars or rods of Corti arise, at first stand nearly parallel, but later separate at their base. He thought that this "von einem Langenwachstum (?) der Zellen selbst oder ihrer Grundlage, der Membrana basilaris, abhiingen kann. "

Hensen ('63) first studied this interesting problem in the ox and found it to depend on a peculiar process. He regarded the inward migration as taking place chiefly in the inner pillar cell. The outer pillar cell in the upper turn moves somewhat outward ; in the base, however, inward. Moreover, the outer pillar cell increases its length during the development of the papilla much more than the inner does. Thus the summit of the arch of Corti and therefore the papilla spiralis shifts inward on the basilar membrane.




CO 1C CO O 1C CO


o^cot^coco^^


GO 1C CO


CO


Os Os Os


-f


1

v

Tf 1C rH CO CO t^.

1C CO CO CO CO T}< i-l i-l rH


rH OS rH O rH rH CO


CO CO OS

rH rH CO


CO


rH CD t- 1 1 1 1 1C


1C ^ 1C


41


1







O CO OS CO O b

CO CO CO OO


? 1 ?!


O


O


^H CO



> *)< 1C


1C


O OS OS


t^


Jj


O rH 1C CO t>- CO


CO OS CO OS


CO CO OS


re



rH CO



>. rH rH


1C


CO * 1C




1 < rH rH CO CO ^


i 1 rH rH


rH rH CO










1


O OS 1C C O CO


CO 00 O OS C-i CO OS CO


o


1C 00 rH 1C



CO 1C -^ f rH rH


00 1C


CO CO CO

CO 1C CO


,>


i


CD CO "*! rH rH rH


rH rH rH


rH i 1 CO










T3~







-c


1C CO 1C 1C 1C *C




Radial distance betw habenula perforata Breadth of membran! (table 9)


Breadth of membran (table 4)


Thickness (table 4)


jj

1

|i

/. -_

3


From hab. perf. to 01 Distance between thi


5 5

-M

c/.

s


O & & g ^J - J3 X! -r=

iiilliiill

^ " S S^

O W (JrJ W


GROWTH OF THE INNER EAR OF ALBINO RAT


119


O C* O5 O b CO

oo t^ co co t o co m coo ^w

<NW CO t GO 1-1 i-i CJ 1-1


^"00 I-H <M 1-1 O

-H t* CO CO C5 <N U3 CO OOO ^i-J CO C<l COt>-t>- i-i ~*^H C^^H


COl>-COCO OOCOO CO ^00 CO(N COC^ lOCOCO-^'H (Ni-i


CO t> CO CO CO W


O -H ~4

O CO "5


00 O O CO 00


o oo oo

CO W


CD 10

CO 00


t^ 00 C^J 00 (N <N


^ M O (N CO IM


O O


(N 00 CO -H

!-H (N i-H


o> o


^H 00


O 00 O> t> "* t^ O C iH CO d CO


O -H

(N -H



Is Is


a


JS


_M ^S ^W -5 o,, W X

13131 ^1

IH ^^ *- ^"'S.'M -S ""

'3 2 '3 j>3 B" *8

fl? fl C? C3 *J? o3 ^5 rt

.9050 a^^a

<_ 5 P ,_ ~ oC.^

o g o S o g g^ c" rt a^os -jfja -g-g


5 '53 o *S .2,213.0.2-3

a p V o fl

1 1 i IN

I'Mg 2? W V v Ja V V

i- S || a a L|SSl3S


HI C~" WH < C/2


120

Bottcher ( '69. 72) disagreed with Hensen, though he has confirmed, as did Middendorp ('67), the striking inward spreading of the base of the inner pillar cell.

Gottstein] ( 72) held that the inner pillar cell does not move inward, but that the increase in the length of the labium tympanicum may explain the peculiar approach of the habenula perforata to the arch of Corti.

Retzius ('84) agreed in general with Hensen 's assertion that in the course of development the surface of the sense organ comes to lie under the basal surface of the membrana tectoria. He thought that this change of position is brought about "weniger in dem Verhalten der Pfeilerzellen, sondern vor allem in dem starken Wachstum der Deitersschen Zellen und der von aussen andriickenden Hensenschen Stiitzzellen, ' and that, further, "vielleicht die Membrana tectoria selbst durch eigenes Wachstum und durch Vergrosserung des Limbus mit seinem Vorspriingen" contributes to this.

Held ('09) agrees with Hensen on the whole.

Prentiss ('13, p. 450) denies the wandering of the spiral organ as follows: There is no necessity for, and my preparations afford no proof of, an inward shifting of the spiral organ and a consequent displacement of the membrana tectoria "

Hardesty ('15, pp. 60 and 61) discussed the relative position of the spiral organ with reference to the basal surface of the tectorial membrane and says " the developed spiral organ acquires its position well under the basal surface of the tectorial membrane almost entirely by being carried axisward during the completion of the membrane." "In the apical turn, where these changes are greatest, the hair cells of the organ may be carried axisward a distance nearly half the width of the membrane. The upgrowth of the outer supporting cells also forces axisward the apical ends of the elements of the spiral organ and in this way contributes a small part to the shift in the relative position of the hair cells. A slight increase in width of the vestibular lip of the spiral limbus may contribute a still smaller part by extending the membrane outward."


GROWTH OF THE INNER EAR OF ALBINO RAT 121

I obtained from the measurements given in the tables the following results concerning the position of the papilla spiralis under the basal surface of the tectorial membrane.

As already stated, since the habenula perforata may be considered after birth as a punctum fixum (Hensen), it is found that the inner pillar cell shifts inward at its inner basal corner during the earlier stage of life. At six days of age it almost always reaches the habenula perforata in the basal turn, though not yet in the apical. At nine days there is no distance between the- habenula perforata and the inner corner of the inner pillar cell.

Gottstein's assumption (no measurements) that the labium tympanicum grows outward and approaches to the arch of Corti is not applicable to the rat, as shown by my tables.

The outer pillar cell also moves outward in all the turns through life, but only slightly after nine days. This result does not agree with that of Hensen ('63), who found in the ox the outer pillar cell to move inward a little at the base, not at all in the middle turn and outward at the apex. Bottcher 's outward movement of the outer pillar cell at the hamulus in the cat is 90 y. and much larger than in the rat.

Contrary to Hensen, Retzius ('84) also finds in the rabbit an outward movement of the base of the outer pillar cell throughout all the turns. On the other hand, during the earlier stages of development, the top of the arch of Corti moves outward from the labium vestibulare through the outward pressure of the greater epithelial ridge. At this stage the main part of the membrana tectoria does not yet reach to the sense cells, though the part produced from the lesser epithelial ridge spans the spiral organ and connects with the outer part of the papilla.

After nine days of age the condition of the organ is quite different. The most remarkable anatomical changes from the earlier condition are the rapid increase in the length of the outer pillar cells, in the height of the pillar cells above the basilar membrane, in the height of the papilla spiralis at the third series of the outer hair cells, in the height of Deiters' cells, and in the height of Hensen 's supporting cells. Also the tunnel of Corti appears.


The greater epithelial ridge has already disappeared in large part and been replaced by a furrow. Pressure displacement of tissue in the direction of the least resistance is common in organogenesis. Thus the inner pillar cell is subject to pressure by the rapid growth of the outward lying and greater part of the papilla spiralis and moves in the direction of the least resistance, therefore inward; the head most and the base not at all. As shown in table 44, the rapid decrease in the radial distance between the labium vestibulare and the head of the inner pillar cell is very evident. The arch of Corti changes its form, now inclining inward, instead of outward as heretofore. The lamina reticularis runs not parallel to the basilar membrane, but ascends outward. The tunnel of Corti also changes more or less its form. Nuel 's space now appears possibly as a result of this displacement of the papilla spiralis. Thus we see a change in the position of the sense organ with reference to the membrana tectoria.

With the inward shifting of the papilla, the hair cells come under the basal surface of the membrana tectoria. It is probable that the increase of the relative length of the membrane also takes part in this, since the increase in the breadth of the inner zone of the membrana tectoria from one to twelve days is as 1:3.4 (table 4), while the increase in the breadth of the basilar membrane is as 1:0.5 during the same interval (table 7).

Prentiss' ('13) statement that an inward shifting of the papilla spiralis and a consequent displacement of the membrana tectoria does not take place (in the pig) is not applicable to the rat.

In the rat the labium vestibulare and the inner edge of the head of the inner pillar cell are also two definite points in the same sense, and using them we see an inward shifting of the organ of Corti. I imagine that his observation may have misled him, since the tectorial membrane arises in his preparations from both greater and lesser epithelial ridges, and from the earlier stages covers with its outer part the papilla spiralis. Thus the shifting of the organ inward does not necessitate a change in the position of the papilla with reference to the membrane. In his study of the tectorial membrane in the same animal (pig) , Hardesty ( ' 13) describes a large displacement of the papilla spiralis inward.

According to him, the shifting of the organ consists of, 1, the moving axisward of the organ itself, and this constitutes the main shift; 2, the upgrowth of the outer supporting cells, and this contributes a small part to the shift, and, 3, a slight increase of the vestibular lip of the spiral limbus which may contribute a still smaller part. The relation in the rat, however, is different. The moving inward of the papilla itself is not seen in the rat. In the earlier stages the inner basal corner of the inner pillar cell alone shifts inward and reaches the habenula perforata. On the other hand, the outer pillar cell moves outward and the head of the inner pillar cell also, at earlier stages, towards the cells of Hensen. Therefore, during the earlier stages the arch of Corti moves rather outward, owing to the pressure of the growth of the greater epithelial ridge. Since the habenula perforata is to be regarded as a fixed point, the inward displacement of the head of the arch of Corti and of the papilla spiralis is not due to the active shifting inward of the organ itself, as Hardesty ('15) thinks, but to the disappearance of the greater ridge and the passive pressure exerted by the upgrowth of the outer pillar cells and Deiters' and Hensen 's cells. The vestibular lip of the spiral lamina and the tectorial membrane itself both increase in their length a little, and these increases play some part in the change of the position of the papilla spiralis with reference to the basal surface of the tectorial membrane.

The membrana basilaris is not concerned with the moving inward of the organ. It increases its length with age in all the turns, but we do not find the change in the position of the feet of the pillar cells on the membrane in such a sense that the feet move inward on it.

Thus the shifting of the papilla spiralis inward in the rat during the development takes place rather in the manner described by Retzius.

Hardesty ('15) states that in the apical turn of the cochlea the organ may be moved axisward a distance equal to about half the maximum width of the greater epithelial ridge, the maximum width of the ridge representing approximately the width of the outspanning zone of the membrane produced upon it.


No other author reports such a high degree of the inward shifting of the organ. I have not studied the pig, but in the rat I get the average distance between the labium vestibulare and the inner edge of the head of the inner pillar cell as follows (table 93).

TABLE 93

Average distance between the labium vestibulare and the inner edge of the inner pillar cell in n (albino rat)


AGE


BODY WEIGHT


TURNS OF COCHLEA


I


II


III


IV


Average


days


grams







(1) 5 (2) 154 Difference betw 1 and 2


9 102 een age groups


94

63 31


124 100 24


1,54 134 20


165

148 17


23


Therefore, in the rat the organ moves inward on the average of 23 [A; that is, in the ratio of 1:0.16 of the maximum distance between these two points. It may be noted that the difference in this table is not the same in the several turns, but diminishes from base to apex a relation which is the reverse of that reported by Hardesty ('15) in the pig. I have no explanation for these differences except their possible dependence on the different animals used.

C. On the growth of the largest nerve cells in the ganglion spirale

Observations. For the present studies the fourteen age groups used in the previous observations on the growth of the tympanic wall of the cochlear duct were employed. In order to see the relation between the growth of the papilla spiralis and the cells of the ganglion spirale, both studies were made on the same sections. In addition, however, I made cross-sections of the cochlea (i.e., at right angles to the axis) in several age groups to follow the growth and the changes in the form of the nerve cells as they appear in this plane. The data for the animals thus used are given in table 94.


For the measurement of the nerve cells a Zeiss system was used with a micrometer eyepiece, having each division equal to 2jx. Since we have in the radial vertical section of the cochlea of the rat at least four turns, there are four cell groups available in each section (fig. 3). The ten largest cells in each ganglion were measured, and thus a total of forty cells in a section were taken for the measurement of the nucleus and the cell.

We used, as stated, four cochleas in each age group, so that 160 cells were measured for each age. Also in the cross-sections the four nearly corresponding turns were used for the measure- ments, selecting the ten largest cells in each turn.

TABLE 04 Data on rals used for cross-sections of the cochlea ganglion spirale


AGE


BOOT WEIGHT


BODY LENGTH


BEX


8IDE


HEARING


days


grams






15


20


84


(?


L.


Prompt response


20


27


93


d"


L.



25


39


114


P


L.



100


95


152


<?


R.



150


169


192


9


L.



371


220


206


c?


L.



In the measurement of the cell bodies the two maximum diameters at right angles to each other were determined, and also the two corresponding diameters for the nuclei.

Here it is to be noted that the expressions turn I, II, III, and IV are used in the same sense as in the earlier chapters.

In table 95 (chart 40) are given the values for the average diameters of the cell bodies and their nuclei in the ganglion spirale in the radial vertical section according to fourteen age groups. Under 'cell body, diameter,' the first column gives the long, the second the short, and the third the computed diameter; i.e., the square root of their products. These last values ap- proximate the mean diameters of the nerve cells. At the foot of the third column are given the ratios from 1 to 20, 1 to 546, and 20 to 546 days. The values for the diameters of the nurlei are similarly given and also the ratios.

As the tables and charts show, the diameters of the cell bodies and also of their nuclei are largest at twenty days of age. After that age they diminish, gradually. While the ratio for one to twenty days is 1:1.7 in the cell bodies and 1:1.3 in the nuclei, that for 1 to 546 days is 1:1.6 and 1:1.2, respectively.

TABLE 95

Diameters of the cell bodies and their nuclei in the ganglion spirale (radial-vertica I

section) (chart 40)





Diameters in M





Cell body


Nucleus


AGE


BOOT


BODY





WEIGHT


LENGTH











Long


Short


Computed


Long


Short


Computed


days


grams


mm.








1


5


48


11.0


10.0


10.5


8.2


7.6


7.9


3


8


56


12.0


11.1


11.5


8.2


7.8


8.0


6


11


63


13.6


12.3


12.9


8.8


8.1


8.4


9


10


58


14.3


12.8


13.6


8.9


8.2


8.5


12


13


70


14.6


13.1


13.8


8.7


8.2


8.5


15


13


75


15.7


14.1


14.9


9.1


8.4


8.7


20


29


95


19.0


17.3


18.1


10.3


10.0


10.2


25


36


104


18.5


16.9


17.7


10.2


9.9


10.1


50


59


125


18.5


16.6


17.5


10.3


9.7


10.0


100


112


159


18.1


15.7


16.9


9.8


9.2


9.5


150


183


190


18.2


15.3


16.7


9.6


8.8


9.2


257


137


175


18.5


15.3


16.8


9.9


9.4


9.6


366


181


191


18.6


15.3


16.9


9.8


9.0


9.4


546


255


213


18.6


15.3


16.9


9.7


9.0


9.4


Ratios







120 days



1:1.7




1:1.3


1546 "



1.6




1.2


20546 "



0.9




0.9


In table 96 (chart 41) are a series of computed diameters of the cell bodies and of their nuclei according to the turns of the cochlea. At the bottom of each column are given the ratios from 1 to 20, 1 to 546, and 20 to 546 days. Determining the ratios for each column, it appears that in general the diameters of the cell bodies and their nuclei are largest at twenty days throughout all the turns. This increase is very considerable from fifteen to twenty days. Then they decrease very slowly till 546 days.


GROWTH OF THE INNER EAR OF ALBINO RAT


127


Table 97 enables us to compare the ratios in the diameters of the cell bodies and their nuclei in turns I, II, III, and IV in the condensed age groups. In both the cell bodies and their nuclei the ratios become slightly larger in passing from the basal toward the apical turn, except in the one day group, which it reversed.

On the comparison of the diameters of the nerve cell bodies and their nuclei in the ganglion spirale according to sex. For this comparison seven age groups were used. In each age group we have sometimes one, sometimes two cochleas of the same sex.



Chart 40 Showing the computed diameter of the largest cell bodies and their nuclei from the ganglion spirale, table 95.

Diameters of the cell bodies.

Diameters of the nuclei.

In the latter case the average value is recorded. In table 98 are given the values for these diameters, and it is plain that there is no significant difference in these values according to sex. On the comparison of the diameters of the nerve cell bodies and their nuclei in the ganglion spirale according to side. For this purpose fourteen age groups were employed. In most cases two cochleas from the same side were used in each age group. In these cases the average value is recorded. Table 99 shows the values for the diameters of the cell bodies and their nuclei accord- ing to side, but reveals no evident difference in this character.


On the morphological changes in the ganglion cells during growth. As my sections could not be stained with thionine, my observations on the Nissl bodies are incomplete, yet the slides stained with Heidenhain's iron haematoxylin and van Gieson's stain, as well as by haematoxylin and eosin, were helpful here.


TABLE 96


Computed diameters of the cell bodies and their nuclei in the ganglion spirale according to the turns of the cochlea (chart 41 )


AGE

days


BODY WEIGHT

gms


TURNS OF THE COCHLEA


Computed diameters M


I


II


in


IV


Cell body


Nucleus


Cell body


Nucleus


Cell body


Nucleus


Cell body


Nucleus


1


5


11.0


8.0


10.8


8.2


10.4


8.0


9.6


7.4


3


8


11.5


7.9


11.5


7.9


11.7


8.0


11.3


8.1


6


11


12.9


8.4


12.6


8.2


13.0


8.5


13.3


8.6


9


10


13.4


8.4


13.4


8.5


13.6


8.6


13.7


8.6


12


13


13.6


8.1


13.5


8.1


13.8


8.6


14.7


9.0


15


13


14.8


8.6


15.0


8.6


14.6


8.6


15.0


9.2


20


29


17.6


10.0


17.6


9.9


18.1


10.2


19.0


10.4


25


36


16.9


9.9


17.6


10.0


17.6


10.1


18.4


10.3


50


59


17.2


9.7


17.2


9.7


17.6


10.0


17.9


10.1


100


112


16.9


9.6


16.9


9.4


16.3


9.3


16.9


9.6


150


183


16.9


9.3


16.3


9.0


16.6


9.1


17.0


9.1


257


137


16.7


9.6


16.7


9.4


16.9


9.7


17.0


9.7


366


181


16.7


9.3


16.4


9.2


16.7


9.1


17.7


9.7


546 255 Ratios 1 20 day* 1546 " 20546 "


15.8 1:1 .6


9.2 1:1.3


16.3 1:1.6


9.4 1:12


16.9 1:1.7


9.4 1:1.3


17.4 1:2 .0


9.5 1:14


1 5


1 2


1 5


1 2


1 7


1 2


1 8


1 3


1.0


0.9


0.r-


1.0


0.?'


0.9


O.S


0.9


TABLE 07 Condensed Ratios of the diameters of the cells and nuclei of the ganglion spirale


AVERAGE AGE


AVERAGE BODY WEIGHT


RATIOS BETWEEN TURNS


I-II


l-lll


I-IV


Cell body


Nucleus


Cell body


Nucleus


Cell body


Nucleus


days

1

8 18 13


grams 5 11 21 138


1 :0.98

0.99
1.01
0.99


1: 1.25

1.00
1.00
0 99


1:0-95

1.01
1.01
i.OI


1 : 1 . 00

1.02
1.01
1 . 00


1 : . 87

1.03

1.04

1.04


1 :0.93

1.05
1 . 05
1.02


GROWTH OF THE INNER EAR OF ALBINO RAT


129


19 M 18

17 16 15 14 13 12


10 9


Si;


DAYSi-

i i




25


50


, oo 2OO 3OO 4OO


Chart 41 'The computed diameter of the largest cell bodies and of their nuclei from the ganglion spirale, according to the turns of the cochlea, table 96. Upper graphs: diameters of the coll bodies. Lower graphs: diameters of the nuclei of the cells.


130


Figure 13 illustrates semidiagrammatically the nerve cells in the spiral ganglion of the albino rat at 1 day and at 20 and 366 days.

The body of the ganglion cells at birth is small and has the characteristic fetal form. The cytoplasm is homogeneous and scanty and the Nissl bodies are not yet seen. The nucleus forms


TABLE 98


Comparison according to sex of the diameters of the cell bodies and the nuclei in

the ganglion spirale


AGE


BODY WEIGHT


NO. OF RAT8


SEX


COMPUTED DIAMETERS M


Cell


Nucleus


days


grams






3


7


1


&


11.4


8.0



8


1


9


11.4


8.0


6


11


2


tf


13.1


8.5



10


2


9


12.8


8.4


9


10


2


c?


13.6


8.5



9


2


9


13.5


8.6


12


14


2


c? 1


13.7


8.5



12


2 .


9


13.9


8.4


100


146


. 1


<?


17.2


9.6



103


1


9


16.9


9.4


150


189


1


d 1


16.5


9.1



154


1


9


17.1


9.1


365


205


1


d 1


16.3


9.0



170


1


9


16.7


9.1


Average male


14.5


8.7


Average f e male


14.6


8.7


Male larger than female


3


3


Female larger than male


3


2


Male and female equal


1


2


the greater part of the cell. The chroma tin is not yet well differentiated, and the so-called 'Kernfaden' are not visible.

The sharply marked nucleolus is in most cases in the central position, but sometimes located peripherally.

The cytoplasm matures rapidly. At six days the Nissl bodies appear, though they are of course, less abundant and smaller than in the later stages. The nucleus develops also and the chromatin is well differentiated. Thus the development in both the cell body and the nucleus proceeds rapidly in the earlier stage.



20 Days


13



366 Days


Fig. 13 Showing semi-diagrammatically the size and the morphological changes in the ganglion cells in the ganglion spirale of the albino rat at the age of 1, 20 and 366 days. All cell figures have been uniformly magnified 1000 diameters.


GROWTH OF THE INNER EAR OF ALBINO RAT


131


At twenty days the cell body reaches its maximum size. The Nissl bodies are large and abundant. The nucleus also attains

TABLE 99

Comparison according to side of the cell bodies and their nuclei in the ganglion

spirale


AGE




SIDE


COMPUTED I.I \ M K r Ml- ft




Cell


Nucleus


days


grams






1


5


2


R.


10.6


8.0





L.


10.4


7.8


3


7


1


R.


11.4


8.0





L.


11.5


8.0


6


11


2


R.


13.0


8.5





L.


12.9


8.4


9


9


2


R.


13.4


8.5





L.


13.7


8.6


12


12


1


R.


13.9


8.4





L.


14.0


8.4


15


13


1


R.


14.7


8.6





L.


14.8


8.5


20


29


2


R.


18.0


10 1





L.


18.5


10.2


25


36


2


R.


17.6


10.1





L.


17.7


10 1


50


59


2


R.


17.5


9.9





L.


17.5


9.8


100


102


2


R.


16.8


9.5



123



L.


17.0


9.5


150


189


1


R.


16.4


9.2





L.


16.5


9.1


257


137


2


R.


17.1


9.7





L.


16.6


9.5


367


175


2


R.


17.3


9.7


365


188



L.


16.5


9.1


546


255


2


R.


16.9


9.3





L.


16.9


9.9


Average right side Average left side Right larger than left Left larger than right Right and left equal


15.3 ir>.:j 4 8 2


9.1 '.M) 7 2 5


its maximum size at this age, though the rate of increase is slower than that for the cell body. With this increase of size the his- tological structure becomes that of the adult rat. Then, as the


132


ANATOMICAL AND PHYSIOLOGICAL STUDIES ON


age advances, the size of both the cell body and of the nucleus slowly diminishes, while within the cytoplasm the differentiation of the Nissl bodies progresses. This relation is seen in the figure of the cell at 366 days, which shows that the absolute volume of the cell body and also of the nucleus is smaller than at twenty days.

From twenty to 366 days, gradual and progressive changes in all histological structures can be seen, though there are no sudden changes.


TABLE 100


Diameters of the cell bodies and their nuclei in the ganglion spirale in cross sections

of the cochlea (chart 4%)




DIAMETERS IN M


AGE


BODY


Cell body


Nucleus




Long


Short


Computed


Long


Short


Computed


days


grams








15


20


15.7


14.3


15.0


9.3


8.4


8.8


20


27


18.3


16.6


17.4


10.3


10.0


10.1


25


39


18.0


16.6


17.3


10.1


9.8


9.9


100


95


17.6


16.2


16.9 '


9.9


9.5


9.7


150


169


17.4


16.0


16.7


9.8


9.1


9.4


371


220


16.5


15.8


16.2


9.5


8.6


9.0


Ratios 15 25 days



1 1.1




1 1.1


15371 "



1.1




1.0


25371 "



1.0




0.9


The question here arose whether this change in volume was in any way related to a shift in the long axis of the cell at the later ages. To answer this difficult question it was deemed desirable to compare the form of the ganglion cells obtained in the cross-section with that found in the radial section of the cochlea. In table 100 (chart 42) are given the values for the diameters of the cell bodies and their nuclei in the ganglion spirale in the cross-section. Below are given the respective ratios from 15 to 25, 15 to 371, and 25 to 371 days. Both cell body and nucleus increase in size up to twenty days and then diminish very slowly, as the age advances. These are similar to the relations found in the radial sections.


GROWTH OF THE INNER EAR OF ALBINO RAT


133


Looking at the diameters of the cell bodies and their nuclei in each turn (table 101), we do not find in the later age groups a regular increase in passing from the base toward the apex, as in the cells on the radial section. The differences are generally

TABLE 101

Diameter of the cell bodies and their nucki in the ganglion spirale according to the turns of the cochlea (cross section)





TURNS OV THE COCHLEA


AGE


BODT WEIGHT



I


II


ill


IV





Computed diameters ft




Cell body


Nucleus


Cell body


Nucleus


Cell body


Nucleus


Cell body


Nucleus


days 15


grams 20


15.0


8.7


14.7


8.8


14.9


8.9


14.9


9


20


27


16.7


9.7


17.2


10.0


17.5


10.1


18.1


10 6


25 100


39 95


16.9 17.2


10.0 10.0


17.2 16.9


9.9 9.6


17.6 16.7


9.8 9.6


17.3 16.8


10.0 9 6


150


169


17.0


9.9


16.6


9.3


16.6


9.4


16.4


9 1


371 Ratio 15-


220 371 days


16.2 1:1.1


9.6 1:1.1


16.2 1:1.1


9.1 1:1.0


16.0 1:1.1


8.7 1:1.0


16.3 1:1.1


9.0 1:1.0


20


15


10



AGE DAYS-


O


25


50


Chart 42 The average diameter of the largest cell bodies and of their nuclei of the nerve cells from the ganglion spirale, after 15 davs (cross-section) table 100.

Cell bodies. -.-.-.-.-. Nuclei.


134 ANATOMICAL AND PHYSIOLOGICAL STUDIES ON

far smaller than on the radial section. This result seems to have some connection with the position of the long axis of the ganglion cells in relation to the axis of the cochlea.

Comparing the diameters of the cell bodies and their nuclei in nearly corresponding places in the radial and cross-section, the long diameters of the cells are in each age group almost always larger in the radial than on the cross-section. Therefore the cells are somewhat ovoid. The short diameters, however, are at the same age sometimes longer, sometimes shorter on the radial than on the cross-sect on. This is probably due to the fact that in the upper turns the cells stand with their long diameter more nearly parallel to the axis of the modiolus, and therefore, on passing from the upper to the lower turn, the long axes of the cells become more inclined to the modiolus.

In order to show that the cell form is ovoid, I reconstructed the cells at 15, 100, and 365 days of age by the usual method, and obtained models which agreed in form with that determined by the microscope.

It appears, therefore, that while there is some difference in the diameters of these cells according to the plane of the section, neverthless, the change in volume after twenty days is similar in both cases, and so this change does not depend on the plane in which the sections were made.

On the nucleus-plasma relations of the cells in the ganglion spirale. The computed diameters of the cell bodies and their nuclei, measured on radial sections, are given in table 102 and the nucleus-plasma ratios have been entered in the last column. The ratio is at one day only 1:1.3 and increases rapidly and regularly till twenty days; after that period there are slight fluc- tuations. Generally speaking, the ratios increase with the ad- vancing age of the rat, but after twenty days only very slightly. Thus we see that the nucleus-plasma relation nearly reaches an equilibrium at twenty days, though the cells mature slowly even after that time.

When we consider this relation according to the turns of the cochlea, we find that this ratio increases in all the turns regularly and definitely till twenty days, after which there are some


GROWTH OF THE INNER EAR OF ALBINO RAT


fluctuations (table 103). Thus we see here also the same relation as before.


TABLE 102 Nucleus-plasma ratios of cells in the ganglion spirale (radial-vertical section)


AGE


BODY WEIOHT


BOOT LENGTH


COMPUTED DIAMETERS M


Cell body


Nucleus


N ucleus-plasma ratios


days


grams


mm.





1


5


48


10.5


7.9


1 : 1.3


3


8


56


11.5


8.0


2.0


6


11


63


12.9


8.4


2.6


9


10


58


13.6


8.5


3.1


12


13


60


13.8


8.5


3.3


15


13


75


14.9


8.7


4.0


20


29


95


18.1


10.2


4.6


25


36


104


17.7


10.1


4.4


50


59


125


17.5


10.0


4.4


100


112


159


16.9


9.5


4.6


150


183


190


16.7


9.2


5.0


257


137


175


16.8


9.6


4.4


366


181


191


16.9


9.4


4.8


546


255


213


16.9


9.4


4.8


TABLE 103

Nucleus-plasma ratios of cells in the ganglion spirale according to the turns of the cochlea. Based on table 96


AQB


BODY WEIOHT


TURNS Or THE COCHLEA


I


ii


in


IV


days


grama






1


5


1 :1.6


1 :1.5


1 :1.2


1 : 1.2


3


8


2.1


2.1


2.1


1.7


6


11


2.6


2.6


2.6


2.7


9


10


3.1


2.9


3.0


3.0


12


13


3.7


3.6


3.1


3.4


15


13


4.1


4.3


3.9


3.2


20


29


4.5


4.6


4.6


5.1


25


36


4.0


4.5


4.3


4.7


50


59


4.6


4.6


4.5


4.6


100


112


4.5


4.8


4.4


4.5


150


183


5.0


4.9


5.1


5.5


257


137


4.3


4.6


4.3


4.4


366


181


4.8


4.7


5.2


5.1


546


255


5.1


4.2


4.8


5.1


136


ANATOMICAL AND PHYSIOLOGICAL STUDIES ON


In the nucleus-plasma ratio of the cells on the cross-section, as shown in table 104, the increase with age is very regular. As the diameters of the cell bodies and their nuclei decrease slowly after twenty days, this increase of the ratio means that the nuclei are diminishing relatively more rapidly than the cytoplasm.

Comparing these ratios from the radial and cross sections, we find that they agree (table 105) .

TABLE 104

Nucleus-plasma ratios of the cells in the ganglion spirale (cross-sections)





COMPUTED DIAMETERS M




BODY LENGTH



AGE


BODY WEIGHT









Cell body


Nucleus


Nucleus-plasma ratios


days


grams


mm.





15


20


84


15.0


8.8


1 4.0


20


27


93


17.4


10.1


4.1


25


39


114


17.3


9.9


4.3


100


95


152


16.9


9.7


4.5


150


169


192


16.7


9.4


4.6


371


220


206


16.2


9.0


4.8


TABLE 105

The nucleus-plasma ratios according to the plane of the section at two age periods

albino rat


AGE


NUCLEUS-PLASMA RATIO ON THE RADIAL SECTION


NUCLEUS-PLASMA RATIO ON THE CROSS SECTION


AGE


days 15


1 :4.0


1 :4.0


days 15


366


1 :4.8


1 :4.8


371

Discussion

According to the foregoing data, the maximum size of the cells in the ganglion spirale, at twenty days, is in cross-sections about 18.7 x 16.9 y. for the cell body and 10.3 x 10.0 [L for the nucleus. Both the long and short diameter of the cell body thus obtained is therefore a little less than that obtained in the radial section, while the diameters for the nu- cleus are the same.

In the literature we have not found any data for the Norway rat, but there are a few observations on the size of these cells in other mammals by Kolliker ('67) and von Ebner ('02).


Schwalbe ('87) and Alagna ('09) find these ganglion cells 25 to 30 JJL in diameter in the guniea-pig and cat.

Alexander ('99) has also reported measurements on a series of mammals, but as the size of such cells is greatly influenced by the method of preparation, and as our averages are based on the largest cells while those of other authors have been ob- tained in a different manner, it seems best not to report the other values in the literature, as they are sure to be misleading.

TABLE 106

Showing the changes with age in the diameters of the cells and the nticlei of the sjriral ganglion afnd the lamina pyrmidalis of the cerebral cortex, respectively


AGE '


CELL BODY IN THE OANQL. SPIRALS COMPUT- ED DIAM. M


CELL BODY IN THE LAMINA PYRAMID COM- PUTED DIAM.


NUCLEUS IN GANOL. SI-IK. COMP. DIAM.


NUCLEUS IN THE LAMINA PYRAM. COMP. DIAM.


AGE


days






days


1


10.5


11.4


7.9


9.4


1


20


18.1


18.7


10.2


15.7


20


546


16.9


17.0


9.4


13.8


730


Ratio be-






ratio


tween 1 and


1 : 1.7


1 :1.6


1 :1.3


1 :1.3


of Ito


20 days






20







days


Ratio be-






ratio


tween 1 and


1 : 1.6


1 : 1.5


1 :1.2


1 :1.2


of Ito


546 days






730







days


Considering the course of growth in these cells, we find it to be similar in both the spiral ganglion and the lamina pyramidalis of the cerebral cortex (rat) as reported by Sugita ('18). In the former the cells attain at twenty days of age, the time of wean- ing, their maximum size, and then diminish slowly with advancing age. The cells of the lamina pyramidalis also reach their full size at twenty days, and then diminish in the same way. There- fore, the course of the growth of both of these groups of nerve cells coincides. However, I do not know of other instances of the phenomenon. When tabulated, the relations here noted appear as in table 106.

The difference between them is only in the absolute values of the diameters of the cell bodies and especially of the nuclei,


138

the nuclei in the cells of the lamina pyramidalis being decidedly larger than in those of the spiral ganglion. The ratios of in- crease are, however, similar.

When we consider the increasing ratios of the diameters of the ganglion cells, we see a close similarity in the maximum values between the cells in the spiral and gasserian ganglion (Nittono, '20). Nevertheless while in the former the ratios from 1 to 20 and 1 to 366 days are in the cell bodies 1:1.7 and 1 : 1.6, respec- tively, in the latter the ratios for the corresponding intervals are 1: 1.43 and 1: 1.69, respectively (Nittono, '20, p. 235). In the nucleus also similar relations are to be seen in both ganglia.

As these ratios show, there is in the gasserian ganglion a definite increase in the diameters of cells and nuclei after 20 days of age; the time when the maximum is reached by the cells of the spiral ganglion. Thus the former continue to grow after growth in the latter has ceased. These results suggest that the neurons in the more specialized ganglia, like the spiral ganglion, may mature earlier than do those in the less specialized.

On the correlation between the growth of the hair cells of the papilla spiralis and of the nerve cells of the ganglion spirale. When we compare the growth changes in the hair cells with those in the ganglion cells, we find that the course of the development is similar. Both classes increase in volume from one to twenty days of age, then tend to diminish slowly the hair cells more slowly than the ganglion cells. In the ratios of increase, however, there are marked differences. Thus in table 67 (bottom of last column) the volume ratios from 1 to 20 and 20 to 546 days are 1 : 2.4 and 1 : 0.9, respectively in the hair cells, and in the ganglion cells, table 108, the ratios of the volumes in the fourth column work out for the corresponding ages as 1: 5.1 and 1: 0.8, re- spectively. In the case of the nuclei the growth changes are somewhat different. In the hair cells the nucleus grows in diameter more rapidly, and therefore reaches at nine days its maximum value and then diminishes at succeeding ages.

I have sought to determine whether there was any correlation in growth between either the entire cylindrical surface or the area of the cross-section of the hair cells, on the one hand and the volume


139


of the cells of the ganglion spirale on the other. The reason for making this comparison was the fact that Levi ('08), Busacca ('16), and Donaldson and Nagasaka ('18) have noted in the cells of the spinal ganglia of several mammals that the postnatal growth in volume was correlated with the increase in the area of the body surface, and recently Nittono ('20) has found in the rat a similar relation between the growth of the cells of thegasserian ganglion and the area of the skin of the head. On examining this problem, it is evident that the correlations thus far reported

TABLE 107

Comparison of ratios between the volumes of the cells of the ganglion spirale. nn<l ///

ratios of the area of the cylijidrical surface of the hair

cells of the organ of Corti on the maximum values


AOE


BOOT WEIGHT


VOLUME OP 1 III ClANllI.ION CELL, /'


RATIOS ON THE MAXIMUM VALUE


AKEA OF CYLINDRICAL SURFACE OF THE HAIR CF.LLH- M *


1ATIO8 ON THE MAXIMUM VALUE


days


gms.




I


5


606


3105


1 :5.12


395


723


1


1.83


3


8


796




3.90


463





1.56


6


11


1124




2.76


582





1.24


9


10


1317




2.36


648





1.12


12


13


1376




2.26


681





1.03


15


13


1732




1.79


729





0.99


20


29


3105




1.00


723





1.00


25


36


2903




1.07


691





1.05


50


59


2806




1.11


697





1.04


100


112


2527




1.23


678





1.07


150


183


2439




1.28


691





1.05


257


137


2483




1.25


689





1.05


366


181


2527




1.23


683





1.06


546


255


2527




1.23


699





1.03


apply to the postnatal growth period, and that we must consider that the functional relations of the skin are well established, even at the earliest age. The data with which we have worked in the case of the cochlea are presented in several tables (107 to 110).

In tables 107 and 108 are given the volumes of the cells of the ganglion spirale and the areas of the cylindrical surface of the hair cells. In table 107 the ratios are computed by dividing the maximum value by the values at each age, and in table 108 by dividing the values at each age by the initial value.


TABLE 108

Comparison of the ratios of the volume of the cells of the ganglion spirals with the

ratios of the area of the cylindrical surface of the hair cells of the organ of

Corti on the initial values


AGE


BOOT WEIGHT


VOLUME OF THE GANGLION

CELLS M *


RATIOS ON THE INITIAL VALUE


AREA OF THE CYLINDRICAL SURFACE OF THI HAIR CELLS M


RATIOS ON , THE INITIAL \ VALUE


days


grams




1


5


606 : 606



1


1.00


395


395



1


1.00


3


8


796




1.31



463




1.17


6


11


1124




1.85



582




1.47


9


10


1317




2.17



648




1.64


12


13


1376




2.27



681




1.72


15


13


1732




2.86



729




1.85


20


29


3105




5.12



723




1.83


25


36


2903




4.79



691




1.75


50


59


2806




4.63



697




1.76


100


112


2527




4.17



678




1.72


150


183


2439




4.02



691




1.75


257


137


2483




4.10



689




1.74


366


181


2527




4.17



683




1.73


546


255


2527




4.17



699




1.77


TABLE 109

Area of the cross-section of the inner and outer hair cells






WEIGHTED





DIAMETER OF


AVERAGE


DIAMETER OF


WEIGHTED


AGE


BODY


ONE INNER


DIAMETER OF


INNER AND


AREAS OF CROSS



WEIGHT


HAIR CELL


THREE OUTER


OUTER HAIR


SECTION OF




M


HAIR CELLS


CELLS


HAIR CELLS





M


M


M 2


days


grams






1


5


6.6


6.0


6.2


30


3


8


8.0


7.4


7.6


45


6


11


8.1


7.6


7.7


48


9


10


8.8


8.5


8.6


5S


12


13


8.5


8.3


8.4


55


15


13


8.4


7.7


7.9


50


20


29


8.8


8.2


8.4


55


25


36


8.8


8.1


8.3


55


50


59


8.8


8.2


8.4


55


100


112


8.6


8.1


8.2


53


150


183


8.5


8.3


8.4


55


257


137


8.5


8.3


8.4


55


366


181


8.8


8.4


8.5


58


546


255


8.6


8.2 | 8.3


55


GROWTH OF THE INNER EAR OF ALBINO RAT


141


I have calculated the cylindrical surface of the hair cells according to the formula for the lateral surface of a cylinder; therefore, this area equals 2 v r a (r = radius, a = height of the cylinder) . As the hair cells are more or less pointed at their lower end, the surface obtained by this formula has nearly the value of the total surface of the hair cells less that for the upper end disk.

As has been already shown, both classes of cells grow rapidly from birth to twenty days, and after that both tend to decrease slightly in volume. It is evident that during the growing period,

TABLE 110

Comparison of the ratios of the volume of the cells of the ganglion spirale with the

ratios of the areas of the cross-section of the inner and outer hair cells

of the organ of Corti


AOE

days


BODY WEIGHT

gms


VOLUME OF THE GANGLION CELLS M '


RATIOS ON THE INITIAL VALUE


AREA Or THE CROSS-SECTION OF THE HAIR CELLS


RATIOS ON THE INITIAL VALUE


1


5


606


606


1


1.00


30 :30


1


1.00


3


8



796



1.31


45



1.50


6


11



1124



1.85


48



1.60


9


10



1317



2.17


58



1 . 9


12


13



1376



2.27


55



1.83


15


13



1732



2.86


50



1.67


20


29



3105



5.12


55



1.83


25


36



2903



4.79


55



l s:;


50


59



2806



4.63


53



1.77


100


112



2527



4.17


53



1.77


150


183



2439



4.02


55



1.83


257


137



2483



4.10


55



1.83


366


181



2527



4.17


58



1.93


546


255



2527



4.17


55



1.83


from one day to the end of the record, the volumes of the ganglion cells increase more rapidly than do the cylindrical areas of the hair cells (table 108). If we seek a numerical expression of these relations, it seems best to start not with the values at birth, but with those at nine days of age when the cochlea is just beginning to function, and to extend the comparison only up to twenty days when both groups of cells have reached their maximum size. Thus at nine days (table 108) the volume of the ganglion cells is 1317 [A 3 , while at twenty days it is 3105 [A 3 , or as 1: 2.3, while the area of the cylindrical surfaces of the hair cells at the respective


142 ANATOMICAL AND PHYSIOLOGICAL STUDIES ON

ages is 648 [x 3 and 723 [i 3 , or as 1 : 1.1, thus showing a rapid growth of the ganglion cell bodies accompanied by but slight enlargement of the hair cells.

It is evident from these ratios that the ganglion cells are increasing in volume more rapidly than the hair cells in area. It is possible that the nervus cochlearis innervates the other cells of the cochlea as well, but even if this is taken into con- sideration the general relations remain the same.

It follows from this that during the period between the earliest appearance of the functional response (nine days) and the attainment of the maximum size of the cells, the innervation of the hair cells is steadily improving, if we may infer such an improvement from the increase in the volume of the ganglion cells. After the close of this early growing period the relations are approximately fixed through the remainder of life. We do not find, therefore, in the cochlea any relation which corres- ponds to those found between the spinal ganglion cells or those of the gasserian ganglion and the associated areas of the skin during postnatal growth. This seems to indicate that in the cochlea growth is fixed or limited, while in the body as a whole it is more or less continuous, and the ganglion cells behave differently in the two cases.

In table 109 are shown the diameters of the inner and outer hair cells and their weighted diameters. In the last column is given the area of the cross-section of the hair cells.

The ratios of these areas on the initial area are shown in table 110 in comparison with the volumes of the ganglion cells on the initial volume, and indicate that from three days of age the values for the ganglion cells are increasing more rapidly than those for the area of the cross-section of the hair cells, and at twenty days the increase in the case of both elements has reached a maximum. Here, as in the case of the cylindrical surface, both elements show like phases of growth, but the increase in the volumes of the ganglion cells is much greater than the increase in the cylindrical area or cross-section of the hair cells.

As it may be desirable to use for comparison the measure- ments on the cells of the ganglion spirale as here reported, the


GROWTH OF THE INNER EAR OF ALBINO RAT


143


constants for the determinations based on 160 cells in each age group are given in . table 111 for the radial vertical sections and in table 112 for the cross-sections.

TABLE 111

A nalytical constants* giving the mean, standard deviation and coefficient of variability unth their respective probable errors for the diameters of the cells and their nuclei of the ganglion spirale in radial vertical section


AOK

days


FOR TOTAL NUMBER "K CELLS


Cell Nucleus


Mean


Standard deviation


Coefficient of variability


1


Cell


10.2 0.05


0.90 0.03


8.9 0.33



Nucleus


7.8 0.02


0.46 0.01


5.9 0.22


3


Cell


11.3 0.03


0.50 0.02


4.4 0.17



Nucleus


7.9 0.02


0.32 0.01


4.1 0.15


6


Cell


12.6 0.04


0.68 0.03


5.4 0.20



Nucleus


8.4 0.03


0.48 0.02


5.7 0.22


9


Cell


13.1 0.03


0.61 0.02


4.7 0.18



Nucleus


8.5 0.03


0.52 0.02


6.1 0.23


12


Cell


13.4 0.05


0.86 0.03


6.4 0.24



Nucleus


8.4 0.03


0.61 0.02


7.3 0.28


15


Cell


14.6 0.04


0.73 0.03


5.0 0.13



Nucleus


8.7 0.03


0.58 0.02


6.7 0.25


20


Cell


17.8 0.06


1.17 0.04


6.6 0.25



Nucleus


10.0 0.02


0.40 0.02


4.1 0.15


25


Cell


17.3 0.05


0.88 0.03


5.1 0.19



Nucleus


9.9 0.02


0.36 0.01


3.6 0.14


50


Cell


17.2 0.04


0.78 0.03


4.5 0.17



Nucleus


9.7 0.02


0.34 0.01


3.6 0.14


100


Cell


16.5 0.03


0.65 0.02


3.9 0.15



Nucleus


9.4 0.02


0.38 0.01


4.0 0.15


150


Cell


16.4 0.03


0.79 0.02


4.8 0.18



Nucleus


9.1 0.02


0.42 0.02


4.6 0.17


257


Cell


16.6 0.06


1.09 0.04


6.6 0.25



Nucleus


9.5 . 02


0.39 0.01


4.1 0.15


366


Cell


16.7 0.05


1.02 0.01


6.1 0.22



Nucleus


9.3 0.03


0.52 0.02


5.6 0.21


546


Cell


16.7 0.06


1 . 06 . 04


6.4 24



Nucleus


9.3 0.02


0.45 0.02


4.9 is


Conclusion

For the study of the growth of the nerve cells in the ganglion spirale fourteen age groups were taken and the data obtained from the 160 largest cells in each age group. Besides these, six age groups, representing six cochleas, were examined in cross-sections to determine the form of the ganglion cells and the relation of their long axes to the axis of the cochlea. Here also the ten largest cells in each of four, nearly corre- sponding turns, were measured. We obtained the following results :

1 . As thus prepared, the ganglion cells at birth have a maximum size of 11 x 10 [i in cell body and 8.2 x 7.6 [x in nucleus. At twenty days the diameters are the largest, 18.7 x 16.9 [x in cell body and 10.3 x 10.0 [x in nucleus.

TABLE 112

Analytical constants giving the mean, standard deviation and coefficient of vari- ability with their respective probable errors for the diameters of the cells and their nuclei of the ganglion spirale, in cross-section


AGE


CeU Nucleus


FOB TOTAL NUMBER OP CELLS


Mean


Standard deviation


Coefficient of variability


days 15


Cell


14.7 0.04


0.40 0.03


2.7 0.21



Nucleus


8.9 0.04


0.34 0.03


3.8 0.29


20


Cell


17.1 0.09


0.83 0.06


4.9 0.37



Nucleus


10.0 0.06


0.58 0.04


5.8 0.44


25


Cell


17.1 0.07


0.63 0.05


3.7 0.28



Nucleus


9.8 0.03


0.30 0.02


3.1 0.23


100


Cell


16.7 0.05


0.44 0.03


2.6 0.20



Nucleus


9.6 0.04


0.36 0.03


3.7 0.25


150


Cell


16.4 0.07


0.69 0.05


4.2 0.32



Nucleus


9 . 4 . 05


. 46 . 03


4.9 0.37


371


Cell


16.0 0.06


0.55 0.04


3.5 0.24



Nucleus


9.1 0.05


0.43 0.03


4.7 0.36


2. The ganglion cells grow relatively rapidly after birth and reach at twenty days of age their maximum size. After having passed the maximum at twenty days, they diminish in size very slowly, but the internal structure matures more and more with successive age.

3. The nuclei are relatively large at birth but increase more slowly than the cell bodies do; nevertheless, they follow the same course of development as the latter. This peculiar course in the growth of the ganglion cells is similar to that followed by the cells of the lamina pyramidalis of the cerebral cortex of the rat as found by Sugita ('18)


4. Within the cochlea the cell bodies and nuclei increase their diameters from the base toward the apex, except in the earlier stages.

5. There are no evident differences in the diameters of the cell bodies and the nuclei of the ganglion cells either according to sex or side.

6. Both the cell bodies and the nuclei are immature at birth, but differentiate rapidly, and even at six days the Nissl bodies are visible. The differentiation proceeds with advancing age.

7. The ganglion cells are bipolar and oval in shape. The direction of the long axis of the cells differs according to the turn of the cochlea and in the upper turn it runs almost parallel to the axis of the modiolus but inclines more and more to the horizontal position on passing to the base.

8. The nucleus-plasma ratios of the ganglion cells increase with age in both the radial and cross-sections.

9. The increase in the volume of the ganglion cells and the area of the cross-section of the hair cells is approximately sim- ilar during the first nine days of life, but after that the ganglion cells increase relatively very rapidly. These relations are very different from those found for the spinal ganglion cells by Don- aldson and Nagasaka ('18) and for the cells of the gasserian ganglion by Nittono ('20).

The nervus cochlearis innervates not only the hair cells, but all the elements of the cochlea, and this may have some in- fluence upon this relation. It is interesting to note that the rate of increase in the cylindrical surface of the hah* cells is similar to that in the area of the cross-sections of these same cells.

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