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|[[File:Mark_Hill.jpg|50px|left]] This historic 1923 book by Wada is a historic description of the {{rat}} {{inner ear}}.
|[[File:Mark_Hill.jpg|50px|left]] This historic 1923 book by Wada is a historic description of the {{rat}} {{inner ear}}.
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'''Modern Notes:''' {{rat}} | {{inner ear}}
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==Contents==
==Contents==
[[#Introduction|Introduction]]


Introduction 5
[[#Material|Material]]


Material 6
[[#Technique|Technique]]


Technique 6
[[Anatomical and physiological studies on the growth of the inner ear of the albino rat 1 (1923)|I. On the growth of the cochlea]]


I. On the growth of the cochlea 12
A. On the growth of the radial distance between the two spiral ligaments


A. On the growth of the radial distance between the two spiral
B. On the growth of the tympanic wall of the ductus cochlearis
ligaments 13


B. On the growth of the tympanic wall of the ductus cochlearis. . . 16
[[Anatomical and physiological studies on the growth of the inner ear of the albino rat 1 (1923)#1. Membrana tectoria|1. Membrana tectoria]]


1. Membrana tectoria 28
[[Anatomical and physiological studies on the growth of the inner ear of the albino rat 1 (1923)#2. Membrana basilaris|2. Membrana basilaris]]


2. Membrana basilaris 39
3. The radial distance between the habenula perforata and the inner corner of the inner pillar cell at base


3. The radial distance between the habenula perforata and  
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
the inner corner of the inner pillar cell at base 47


4. The radial distance between the habenula perforata and
5. The radial basal breadth of the outer pillar cell (including the outer pillar)
the outer corner of the inner pillar cell (resp., the inner
corner of the outer pillar cell) at base 48


5. The radial basal breadth of the outer pillar cell (including
6. The radial distance between the habenula perforata and the outer border of the foot of the outer pillar cell  
the outer pillar) 57


6. The radial distance between the habenula perforata and
7. The greatest height of the greater epithelial ridge (''dem grossen Epithelwulst Bottcher's s. Organon Kollikeri'') resp. of the inner supporting cells


the outer border of the foot of the outer pillar cell 63
8. The radial distance between the labium vestibulare and the habenula perforata


7. The greatest height of the greater epithelial ridge (dem
9. The radial distance between the labium vestibulare and the inner edge of the head of the inner pillar cell
grossen Epithelwulst Bottcher's s. Organon Kollikeri) resp.


of the inner supporting cells 63
10. Vertical distance from the membrana basilaris to the summit of the pillar cells


8. The radial distance between the labium vestibulare and
11. The greatest height of the tunnel of Corti


the habenula perforata 68
12. The height of the papilla spiralis at the third series of the outer hair cells


9. The radial distance between the labium vestibulare and
13. The greatest height of Hensen's supporting cells


the inner edge of the head of the inner pillar cell 71
14. The angle subtended by the extension of the surface of the lamina reticularis with the extended plane of the membrana basilaris


10. Vertical distance from the membrana basilaris to the
15. Lengths of the inner and outer pillar cells
summit of the pillar cells 75


11. The greatest height of the tunnel of Corti 77
16. Inner and outer hair cells


12. The height of the papilla spiralis at the third series of the
17. Deiter's cells
outer hair cells 77


13. The greatest height of Hensen's supporting cells 83
18. Summary and discussion


14. The angle subtended b> the extension of the surface of
C. On the growth of the largest nerve cells in the ganglion spirale
the lamina reticularis with the extended plane of the  
membrana basilaris 84


15. Lengths of the inner and outer pillar cells 85
Observations


16. Inner and outer hair cells 94
Discussion


17. Deiter's cells 109
Conclusions


18. Summary and discussion 116
[[Anatomical and physiological studies on the growth of the inner ear of the albino rat 2 (1923)|II. Correlation between the inception of hearing and the growth of the cochlea]]
 
C. On the growth of the largest nerve cells in the ganglion spirale . 124
 
observations 124
 
Discussion 136
 
Conclusions . ... 143
 
II. Correlation between the inception of hearing and the growth of the  
 
cochlea 145


Observation 146  
Observation 146  
Line 110: Line 91:
Conclusions 155  
Conclusions 155  


III. On the growth of the largest nerve cells in the ganglion vestibulare. . . 156
[[Anatomical and physiological studies on the growth of the inner ear of the albino rat 3 (1923)|III. On the growth of the largest nerve cells in the ganglion vestibulare]]


Material and technique 156  
Material and technique 156  
Line 120: Line 101:
Conclusions 168  
Conclusions 168  


Final summary 169
[[Anatomical and physiological studies on the growth of the inner ear of the albino rat 4 (1923)#Final Summary|Final Summary]]
 
Literature cited . . . 171


[[Anatomical and physiological studies on the growth of the inner ear of the albino rat 4 (1923)#Literature Cited|Literature Cited]]


==Introduction==
==Introduction==
Line 394: Line 374:
pectinata of the membrana basilaris.  
pectinata of the membrana basilaris.  


==On the Growth of the Cochlea==
==Final summary==


As noted above, I have selected from at least seven serially
This study is concerned with the age changes in the organ
sectioned cochleas in each age group, four for this study, taking
of Corti and the associated structures. The changes in the
one section in good condition from each labyrinth. From these
largest nerve cells which constitute the spiral ganglion and the  
four sections the average values were taken for each age. Table 1
vestibular ganglion, respectively, have also been followed from
gives the data for the rats used here. As we see, sometimes two,  
birth to maturity. On pages 116 to 124 are given the summary
sometimes three animals were used at each age to get the four
and discussion of the observations on the growth of the tympanic
best-prepared sections which corresponded. Determinations
wall of the ductus cochlearis.  
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
The conclusions reached from the study of the largest nerve cells
IV turns of the cochlea. This calls for a word of explanation.
in the ganglion spirale appear on pages 143 to 145. On pages
As the cochlea of the rat has nearly 2^ complete turns, four
155 and 156 are presented the results of the study on the correlation
cochlear canals are usually obtained in the radial vertical sections,
between the response to sound and to the conditions of the cochlea.  
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
Finally, the observations on the growth of the largest cells in  
arbitrary, as the changes in the elements take place in a graded
the ganglion vestibu'are are summarized on pages 168 and 169.  
manner.  


It is not necessary to again state in detail the conclusions
reached in the various parts of this study.


At the same time, if we endeavor to obtain a very general
picture of the events and changes thus described, this may be
sketched as follows:


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


170 ANATOMICAL AND PHYSIOLOGICAL STUDIES ON


Within the membranous cochlea there occurs a wave of growth
passing from the axis to the periphery as shown in figures 4 to 13.
The crest or highest point of the tissue mass appears at birth
near the axis, in the greater epithelial ridge, and then progressively shifts toward the periphery, so that at maturity it is in
the region of the Hensen cells. With advancing age the hair
cells come to lie more and more under the tectorial membrane
and the pillar cells seem to shift toward the axis.


TABLE 1
At from 9 to 12 days the tunnel of Corti appears and the rat
Data on the albino rats used for the study of the cochlea
can hear.


All of these changes occur first in the basal turn and progress
toward the apex. The mature relations are established at about
twenty days. There are thus two waves of change in the membranous cochlea, from the axis to the periphery and the other
from the base to the apex. The rat can usually hear at twelve
days of age or about three days before the eyes open.


The largest cells in the ganglion spirale are very immature at
birth, reach their maximum at twenty days, and after that diminish in size, slightly but steadily. The rat hears, therefore,
before these cells have reached their full size.


AGE
The largest cells in the vestibular ganglion are precocious
 
and remarkably developed, even at birth. They cease their  
 
rapid growth at about fifteen days of age, but increase very
BODY WEIGHT
slightly though steadily throughout life.
 
 
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.
 
 
+
 
 
 
 
sections. These distances measure the radial breadth of the
 
membranous cochlea and of the modiolus combined at these levels.
 
In table 2 (chart 1) are entered the values for the radial
 
distances found between the two spiral ligaments in fourteen
 
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
 
 
 
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
 
 
 
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.
 
 
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.
 
 
 
 
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 cochkaris
 
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
 
 
 
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.
 
 
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
21
 
 
 
HS
 
 
 
 
22
 
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
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
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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.
 
 
 
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
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.
 
 
 
40
 
 
 
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}
 
 
 
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
 
 
 
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
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.
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
41
 
 
 
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.
 
 
 
220
 
M
180
 
140
100
60
20
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
i
 
 
 
 
 
 
 
 
 
 
 
 
 
 
*
 
 
 
 
^
 
i
 
-^
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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'
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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G
 
 
E
 
 
D
 
 
A N
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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.
 
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.
 
 
 
42
 
 
 
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
 
 
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Right side
Left side
Average
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
43
 
 
 
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.
 
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).
 
 
 
44
 
 
 
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
 
 
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
 
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
 
 
 
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
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
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
45
 
 
 
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,
 
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
 
 
 
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).
 
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.
 
According to all these authors, the breadth of both the inner
and outer zones increases from base toward apex and results
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
47
 
 
 
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
 
 
 
 
 
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
 
 
 
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
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
 
 
 
48
 
 
 
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
 
 
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
 
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
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
 
 
 
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
 
 
 
TABLE 17
 
 
 
BABBIT
 
 
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
 
 
 
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT 49
 
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.
 
 
 
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
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
 
 
 
 
 
 
 
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
 
 
 
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.
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
51
 
 
 
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
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 "
 
 
 
 
 
 
 
 
 
 
: l.o
 
 
 
40
U
20
 
n
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
"
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
\
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Ab
 
 
 
 
DA'
 
 
/q
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
a
 
 
 
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
 
 
 
52
 
 
 
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
 
 
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
 
 
 
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
 
 
 
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
between the outer corner of the inner pillar (not pillar cell)
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
53
 
 
 
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 "
 
 
 
2.2
1.4
1.1
 
 
 
ou
 
14,
 
60
40
20
 
r\
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
<
 
 
 
 
 
 
t=
 
 
 
 
 
 
 
 
 
 
MM
 
 
 
 
 
.
 
 
=
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
/
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
i
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
/
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
i
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
G
 
 
E
 
 
DA>
 
 
/C
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
 
 
13
 
 
 
o
 
 
 
25
 
 
 
50
 
 
 
50 1OO 20O 3OO 40O 5OO
 
 
 
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.
 
 
 
54
 
 
 
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
 
 
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.
 
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
 
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
 
 
 
 
 
 
 
BATIO8 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.
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
55
 
 
 
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
 
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
 
 
 
56
 
 
 
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
 
 
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
 
c\
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
^
 
 
r*
 
 
r^
 
 
 
 
 
 
 
 
_ !
 
 
1
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
e=
 
 
 
 
 
 
 
 
 
 
 
 
-_
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
G
 
 
^
 
 
c
 
 
A
 
 
/s
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
25
 
 
 
50
 
 
 
50 1OO 2OO 3OO 4OO 5OO
 
 
 
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.
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
57
 
 
 
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).
 
 
 
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
 
 
 
58
 
 
 
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
 
 
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
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
t
 
 
 
 
\,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
 
 
-=a
 
 
<
 
 
 
 
-<
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
G
 
 
 
 
D
 
 
A'
 
 
^
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
i
 
 
 
25
 
 
 
50
 
 
 
5O 1OO 2OO 300 4OO 500
 
 
 
Chart 11 The radial basal breadth of the outer pillar (not pillar cell)
table 29, figure 2, distance 7.
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
59
 
 
 
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
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
61
 
 
 
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
 
 
 
ou
 
M.
40
 
20
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
.-'
 
 
 
 
>-i
 
 
 
 
 
 
 
 
 
 
^
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
a*
 
 
 
 
 
 
 
 
-^
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
'
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
/
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
r~
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
G
 
 
:
 
 
DA >
 
 
/c
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
25 50 50 1OO 20O 30Q 4(X) 5QO
 
 
 
Chart 12 The radial basal breadth of the outer pillar cell, table 32, figure 2,
distance 9.
 
 
 
 
5O 50 1OO 2OO 30O 40O 50O
 
 
 
Chart 13 The radial basal breadth of the outer pillar cell, according to
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
 
 
 
62
 
 
 
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
 
 
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.)
 
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.
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT 63
 
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
 
 
 
64
 
 
 
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
 
 
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
 
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
 
 
 
AG^E DAYSH
 
 
 
O
 
 
 
25 5O 50 too 2OO 3OO 40O 500
 
 
 
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.
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
65
 
 
 
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).
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
67
 
 
 
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.
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT 69
 
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
 
 
 
70
 
 
 
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
 
 
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 speak
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
71
 
 
 
ing, the habenula perforata is to be considered as a 'punctum fixurn, 'at least after birth.
 
9. The radial distance be'.ween 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.
 
 
 
i cr\
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
loO
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
it
 
 
 
 
 
 
 
 
/
 
 
 
 
'
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
a
 
 
 
 
: _
 
 
 
 
*
 
 
 
 
 
 
- v
 
 
 
 
 
 
 
 
/
 
 
^
 
 
 
 
 
 
.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
/
 
 
 
 
 
 
 
 
>
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
\
 
 
 
 
 
 
_
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
140
 
 
 
 
A
 
 
it
 
 
*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
k
 
 
 
 
 
 
;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
^
 
- !
 
 
 
 
 
 
_
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
/
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
/
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
12O
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
,*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
\t\f\
 
 
 
 
 
 
 
 
y
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
~
 
 
~
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1UO
 
 
 
 
1
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Qf\
 
 
 
 
1
 
 
o
 
~j
 
 
^
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
(
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
^
 
 
a
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
ou
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
fj
 
 
i
 
 
 
 
g
 
 
/A
 
f*f\
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
|
 
 
2
 
 
 
 
 
 
 
 
Y
 
 
 
25
 
 
 
50
 
 
 
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
 
 
 
72
 
 
 
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
 
 
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
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
73
 
 
 
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
 
 
 
140
 
 
 
12O
 
 
 
1OO
 
 
 
AGE DAYS'
 
 
 
25
 
 
 
50 50 1OO 2OO 300 400 50O
 
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.
 
 
 
74
 
 
 
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
 
 
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
 
 
 
80
 
 
 
60
 
 
 
40
 
 
 
20
 
 
 
AGE.qAYS
 
 
25 50 5Q 1QO 2OO 300 4OO 5OO
 
Chart 20 The vertical distance from the membrana basilaris to the surface
of the pillar cells, table 46, figure 1, 1-1.
 
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
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
 
 
 
76
 
 
 
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
 
 
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.
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT 77
 
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. There
 
 
78
 
 
 
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
 
 
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.
 
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
 
 
 
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
 
 
 
GROWTH OF THE INNER EAR OF ZLBINO RAT
 
 
 
79
 
 
 
fore, the difference between the ratios at 1 to 20 and 1 to 546
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.
 
 
 
60
40
 
20
n
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
 
 
^
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
JS.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
/
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
x
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
G
 
 
E
 
 
c
 
 
A
 
 
Y5
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
25
 
 
 
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
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
A*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
fir\
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
ou
 
 
 
 
 
 
 
 
 
 
/
 
 
,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
k-
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2
 
 
 
 
 
 
 
 
 
 
 
 
{/
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
""
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
:,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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\
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
/
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
f-'
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
.
 
 
.'"1
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
\
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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\
 
 
 
 
 
 
 
 
 
 
/
 
 
*
 
 
^
 
 
 
 
 
 
 
 
 
 
 
 
 
 
~
 
~
 
 
^
 
 
^
 
 
 
 
 
 
 
 
 
 
 
 
~
 
 
 
 
* *
 
 
"'
 
 
"~
 
 
 
 
 
 
 
 
 
 
 
 
" *
 
 
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
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
^
 
 
<
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
="
 
 
 
 
 
 
 
>
 
 
"^
 
 
 
 
 
 
 
 
 
 
/
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
/
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
~
 
 
 
 
 
 
~
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
/
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
,'
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
>
 
P
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
*-.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
'*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
,/
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
"'
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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)
 
 
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GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
119
 
 
 
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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
 
 
 
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.
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
125
 
 
 
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 measurements, 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 approximate 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.
 
 
 
126
 
 
 
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
 
 
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.
 
 
 
*u
 
M
 
15
 
10
 
5
r\
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
/
 
 
'*
 
 
 
 
 
 
 
 
**
 
 
-4
 
 
 
 
 
 
>
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
'<
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
j
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
f *
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
/
 
 
 
 
 
 
 
 
^
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
?
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
""
 
 
-i
 
 
_
 
 
_
 
 
___
 
 
 
 
J]
 
 
 
 
 
_
 
 
-.
 
 
 
 
 
. _,
 
 
 
 
_
 
 
 
 
..
 
 
_
 
 
 
 
 
 
_.
 
 
 
 
 
 
v*
 
 
'
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
G
 
 
E
 
 
D
 
 
A
 
 
/Si
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
25 50 5Q .Qo 2(X) 30Q 40Q
 
 
 
5OO
 
 
 
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 according to side, but reveals no evident difference in this character.
 
 
 
128
 
 
 
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
 
 
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 histological 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 fluctuations. Generally speaking, the ratios increase with the advancing 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 nucleus 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).
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
137
 
 
 
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 obtained 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 COMPUTED DIAM. M
 
 
CELL BODY IN
THE LAMINA
PYRAMID COMPUTED 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 weaning, 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. Therefore, 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 increase 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, respectively, 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, respectively. 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 consideration 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 corresponds 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 measurements 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
 
 
 
144
 
 
 
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
 
 
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 corresponding 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 variability 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)
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT 145
 
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 similar 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 Donaldson 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 influence 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.
 
II. CORRELATION BETWEEN THE INCEPTION OF HEARING
AND THE GROWTH OF THE COCHLEA
 
The present study aims merely to compare in the rat the
size of each element of the cochlea just before and just after
the appearance of hearing and to ascertain the changes in the
cochlea which take place during this phase. The rats which
have sense of hearing show the so-called ' Ohrmuschelreflex '
 
 
 
146 ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
of Preyer and other responses to auditory tests. Both the guineapig and rat react most evidently to sounds. The former animal
responds usually five to six hours after birth. In the rat, however,
the development of the function is, as already stated, relatively
retarded and usually first appears at about ten days of age.
 
To test the presence of hearing there are several methods,
as for example, Preyer V Ohrmuschelreflex' and the reflex
closure of the eyelid, and these I used in making my observations.
As the source of the sound I selected the hand clap, a whistle
(Triller-pfeife, about c 4 ) and a low sound made by drawing in
the breadth with nearly closed lips (about c 1 ).
 
Since it is my purpose merely to determine the first appearance of a response to sound, it is not nescessary to carry out such
refined examinations as did Hunter ('14, '15, '18) Watson
('07), and others on white rats, and Marx ('09) on the guineapig, nor was it necessary to use the tuning-fork which by the
way is not so good for tests on animals as for those on man.
Since sometimes we may have a defect of hearing in animals,
as shown by many investigators, it was deemed necessary to
use several sources of sound and to take care not to produce
ah* currents striking the test animal or to touch it in any way.
For this purpose a large sheet of glass was placed between the
source of sound and the rats to be tested. While the rat was
resting I suddenly produced the sound and noted whether the
rat responded. When the animals already had their eyes open
the test was made from behind to avoid visual reflexes.
 
Observations
 
Rats at birth show no response to auditory stimuli. Most
of them respond at twelve days of age very clearly, sometimes
at ten to eleven days Under certain circumstances, the time
of the reflex can be rather accurately noted. For example,
while in the morning at ten days no reflex was noted it was
present in the evening of the same day. Fortunately, I obtained
five nine-day-old rats belonging to one litter and in nearly the
same condition of nourishment and developnent. One of these
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT 147
 
responded to the test very evidently at noon on the ninth day,
but the others did not. The sound which was effective was
fairly intense, but to a faint and low-pitched sound this rat
did not respond. In this case the external auditory canal was
open. In the others there was in some a small open canal,
but more or less closed by a cellular plug. In the latter cases
I removed this obstruction without much difficulty or damage
by washing, yet no reaction could be obtained to the stimuli.
As it was to be expected, that also in the latter the reflexes would
very shortly appear, all the cochleas of these young rats, both
the not-hearing and hearing, were fixed by the method previously described and later examined.
 
In chapter 1, in which I followed the growth changes in the
constituents of the membranous cochlea and in its ganglion
cells from birth to maturity, including ' not hearing ' and ' hearing '
rats, very evident differences were observed in rats between
nine and twelve days of age. In view of this, it will be of interest to compare the measurements obtained from the 'not
hearing' and 'hearing' rats nine days old and members of the
same litter. From the differences thus obtained we can conclude
concerning the developmental changes in the cochlea requisite
for the first appearance of hearing, provided there are no obstacles
in the sound-conducting apparatus or deficiencies in the central
organ.
 
In table 113 are given the values for the size of the several
constituents of the cochlea 'from a rat which did not hear and
one which did, at nine days. The former data are the averages
from four cochleas, while the latter are from two. The table
shows in a striking way that where there is a significant difference. The values obtained from the rat which could hear are
usually larger than those of the rat which could not hear.
 
Among these measurements we see sometimes very marked
and sometimes only slight differences. Only the radial distance
between the labium vestibulare and the inner edge of the head
of the inner pillar cell in the first two turns and the diameter of
the nuclei of the inner and outer hair cells are in the former smaller
than in the latter. In both instances, however, these smaller
 
 
 
148
 
 
 
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
 
 
TABLE 113
 
Comparison of the dimensions of the constituents of the cochlea in a hearing rat (H.)
with those in a rat not hearing (N.) at nine days of age measurements
 
in micro
 
 
 
BAT
 
 
AGE
 
 
BODY
WEIGHT
 
 
(N.)
(H.)
 
 
days
9
9
 
 
grams
10
11
 
 
(N.)
(H.)
 
 
1430
1434
 
 
Average
 
 
distance between two spiral ligaments
 
 
 
 
 
Breadth of membrana tectoria
 
 
 
 
 
TURN I
 
 
II
 
 
III
 
 
IV
 
 
Average
 
 
 
 
Th ids ness
 
 
(N.)
(H.)
 
 
243
 
242
 
 
270
268
 
 
304
308
 
 
306
314
 
 
281
283
 
 
 
 
27
27
 
 
 
Breadth of membrana basilaris
 
 
 
 
 
TURN I
 
 
II
 
 
III
 
 
IV
 
 
AVERAGE
 
 
ZONA ZONA
ARCUATA PECTINATA
 
 
(N.)
(H.)
 
 
169
171
 
 
189
186
 
 
202
214
 
 
201
204
 
 
191
196
 
 
79 112
93 103
 
 
Distance between the habenula perforata and the outer corner of the inner
hair cell
 
 
 
 
TURN I
 
 
II
 
 
III
 
 
IV
 
 
AVERAGE
 
 
 
 
(N.)
(H.)
 
 
38
40
 
 
38
42
 
 
44
 
58
 
 
49
60
 
 
42
50
 
 
Distance between habenula perforata and the outer corner ol the outer pillar
cell at foot*
 
 
 
 
TURN I
 
 
II
 
 
ill
 
 
IV
 
 
Average
 
 
 
 
(N.)
(H.)
 
 
70
 
79
 
 
76
 
88
 
 
86
103
 
 
86
102
 
 
79
93
 
 
Height of greater epithelial ridge
 
 
 
 
TURN I
 
 
II
 
 
III
 
 
IV
 
 
AVERAGE
 
 
 
 
(N.)
(H.)
 
 
36
42
 
 
40
43
 
 
41
 
48
 
 
42
50
 
 
40
46
 
 
Distance between the labium vestibulare and the habenula perforata
 
 
 
 
TURN I
 
 
II
 
 
III
 
 
IV
 
 
Average
 
 
 
 
(x.)
 
(H.)
 
 
83
 
85
 
 
108
104
 
 
137
140
 
 
145
150
 
 
118
120
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
149
 
 
 
TABLE 113 Continued
 
Distance between the labium vestibulare and the inner edge of the head of the
 
inner pillar cell
 
 
 
 
 
TURN I
 
 
II
 
 
III
 
 
IV
 
 
Average
 
 
 
 
(N.)
(H.)
 
 
94
 
78
 
 
131
 
108
 
 
168
170
 
 
179
210
 
 
143
142
 
 
Height from basal plane to surface of pillar cells
 
 
 
 
TURN I
 
 
II
 
 
III
 
 
IV
 
 
AVERAGE
 
 
 
 
(N.)
(H.)
 
 
32
40
 
 
33
 
42
 
 
35
 
45
 
 
36
45
 
 
34
43
 
 
Height of tunnel of Corti
 
 
 
 
TURN I
 
 
II
 
 
III
 
 
IV
 
 
AVERAGE
 
 
 
 
(N.)
(H.)
 
 
 
 
20
 
 
 
 
18
 
 
 
 
14
 
 
 
 
11
 
 
 
 
16
 
 
Height of papilla spiralis at the third series of outer hair cells
 
 
 
 
TURN I
 
 
II
 
 
III
 
 
IV
 
 
AVERAGE
 
 
 
 
(N.)
(H.)
 
 
28
42
 
 
28
43
 
 
27
39
 
 
28
36
 
 
28
 
40
 
 
Height of Hensen's cells
 
 
 
 
TURN I
 
 
II
 
 
ill
 
 
IV
 
 
AVERAGE
 
 
 
 
(N.)
(H.)
 
 
20
42
 
 
23
45
 
 
23
 
38
 
 
24
30
 
 
23
 
39
 
 
Angle of lamina basilaris with plane of membrana basilaris degrees
 
 
 
 
TURN I
 
 
II
 
 
HI
 
 
IV
 
 
AVERAGE
 
 
 
 
(N.)
(H.)
 
 
 
 
+7
 
 
 
 
+4
 
 
 
 
-8
 
 
 
7
 
 
 
 
 
 
Length of the inner and outer pillar cells
 
 
 
 
 
INNER
 
TURN I
 
 
II
 
 
III
 
 
IV
 
 
AVERAGE
 
 
 
 
 
 
(N.)
(H.)
 
 
35
36
 
 
39
39
 
 
41
42
 
 
40
45
 
 
39
 
41
 
 
 
 
OUTER
TURN I
 
 
II
 
 
III
 
 
IV
 
 
AVERAGE
 
 
WEIGHTED
AVERAGE
 
 
(N.)
(H.)
 
 
26
45
 
 
26
 
54
 
 
29
50
 
 
29
40
 
 
28
47
 
 
30
46
 
 
 
Volume of inner and outer hair cells
 
 
 
 
 
INNER: AVERAGE
 
 
OUTER: AVERAGE
 
 
WEIGHTED AVERAGE
 
 
(N.)
(H.)
 
 
1798
1815
 
 
1277
1279
 
 
1407
1428
 
 
 
150
 
 
 
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
 
 
TABLE 113 Concluded
Diameter of nuclei of the inner and outer hair cells
 
 
 
 
 
INNER: AVERAGE
 
 
OUTER: AVERAGE
 
 
WEIGHTED AVERAGE
 
 
(N.)
(H.)
 
 
8.3
8.2
 
 
8.0
7.4
 
 
8.1
 
7.6
 
 
 
 
DEITERS' CELLS:
 
VOLUME M '
 
 
DIAMETER OF
NUCLEI
 
 
LENGTH OF CELL
BODY
 
 
PHALANGEAL
PROCESS
 
 
(N.)
(H.)
 
 
518
1193
 
 
7.0
 
7.2
 
 
14
32
 
 
22
22
 
 
 
Ganglion spirale: diameters computed
 
 
 
 
 
CELLS
 
 
NUCLEI
 
 
(N.)
(H.)
 
 
13.6
13.7
 
 
8.5
8.6
 
 
 
values are marks of maturity. These changes in size accord
with the results given in chapter 1 at twelve days of age, though
there are some differences between them in the absolute values.
 
Figures 7 and 8 illustrate the outlines of the tympanic wall
of the membranous cochlea in nine-day-old rats which could
not and could hear, respectively. These figures have been
drawn from the corresponding sections at the beginning of
the middle turn of the cochlea and are comparable with figures
3 to 6 and 9 to 12. On comparing figures 7 and 8, the more
noticeable differences appear to be the following.
 
The membrana tectoria is a bit longer in the hearing rat.
The appearance and the position of it with reference to the
surface of the papilla spiralis is also different. In the not-hearing
cochlea it has an infantile look.
 
The outer end of the main part does not yet reach the second
row of the outer hair cells and connects with the Hensen's
prominence by a thick thread. There are also many fine fibers
to be seen between the basal surface of the membrane and the
papilla. In the hearing rat the fine fibers are absent. The
membrane reaches already the row of the outer hair cells and
there is a strong connection between this part and the terminal
 
ame (Schlussrahmen) of the lamina reticularis by a thick
 
read as shown in figure 8 Thus the position of the membrane
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT 151
 
above the papilla depends a little bit upon the increase of
the length of the membrane itself, but chiefly upon other factors
such as the inward shifting of the papilla. The membrana
basilaris as a whole shows a small increase o" breadth in the
hearing rat. The zona arcuate, however, increases much in
its breadth, while the zona pectinata rather decreases. This
is due to the development of the pillar cells. The base of the
inner and outer pillar cell spread much on the membrane. At
the same time the length of the cells, especially of the outer,
increases nearly twice as much as in the not-hearing rat.
 
Thus the foot of the outer pillar cell moves out ward, as Bottcher
('69, 72) stated, while the inner corner of the inner pillar cell
does not move in any way, as the habenula perforata stands at
a fixed point. This results in a change in the form of the arch
of Corti. The hitherto outward inclined arch tends to bend
inward and between both inner and outer cells arises a space,
the tunnel of Corti. The appearance of the tunnel seems to have
some relation to hearing. The tunnel is always present in the
cochleas of hearing rats. Sometimes the tunnel is present in
the lower turns, but not in the upper turns in the not-hearing rats.
We can say, therefore, that it probably appears through all the
turns before the special function of the cochlea begins. In this
way the zona arcuata of the membrana basilaris increases its
breadth.
 
The next striking change is the rapid increase in the size of
the Deiters' cells, Hensen's cells, and the resultant change of
the form, with an inward shifting, of the papilla spiralis.
 
The Deiters' cells increase their height very rapidly; the length
of the cell body becomes over twice that in the not-hearing rat,
but the processus phalangeus changes only slightly. Hensen's cells develop also, but not so much as Deiters' cells. The
papilla spiralis thus increases in height. On the other hand,
the greater epithelial ridge vanishes inwards from the inner
supporting cells and appears as a furrow the sulcus spiralis
internus. Through the pressure of these outward-lying cells
the papilla spiralis swings inward as a whole, without really
moving on the membrana basilaris. The lamina reticularis
 
 
 
152 ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
 
 
becomes inclined inward instead of outward and subtends a
slight angle with the plane of the membrana basilaris. The
distance from the labium vestibulare to the inner edge of the
head of the inner pillar cell becomes smaller through the inward
shifting of the papilla.
 
In the hair cells and the cells of the ganglion spirale we see
a smaller difference between the hearing and not-hearing rats.
Only the diameter of the nuclei of the hair cells in the hearing
rat diminishes a little, as it continues to do in the adult cochlea.
 
All the changes just enumerated begin at the base of the
cochlea and progress to the apex. Therefore we see the high
and outward ascending papilla spiralis in turn I, while in the
upper turns the papilla is not yet so developed, is smaller in all
the constituents, and shows in general the characters of a younger
and less mature cochlea conditions which disappear with age.
This upper and immature part seems not to respond to the test
for hearing. Indeed, my testing result is positive for sounds of
high pitch, but not for low pitch. Therefore we conclude that
the papilla spiralis develops functionally from base to apex and
that when the papilla spiralis has developed in the basal turns,
but not in the upper turns, it responds to sounds of high pitch
alone.
 
Discussion
 
If we assume that our tests for hearing are trustworthy, then
the differences between the size of the constituents of the cochlea
in nine-day-old rats which could and could not hear will indicate
what developmental changes in the cochlea of the albino rat are
necessary for the appearance of the hearing reflex. Whether all
the differences found by us are necessary is difficult to determine,
and the problem is open for further study; but as the matter
stands, our results give the closest correlation between structural
changes and the appearance of function which has as yet been
reported.
 
Kreidl and Yanase ('07) studied the differences between the
not-hearing and hearing rat and summarized their results on
page 509: "Kurz vor Eintritt des Horreflexes ist das Cortische
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT 153
 
Organ im wesentlichen fertig ausgebildet. " They publish no
measurements nor data. The condition of the development of
the organ of Corti described as 'fertig ausgebildet' is not sufficiently precise.
 
Further, on the same page they say, "Der auffalligste und,
soweit die Untersuchungen bis jetzt eregben haben, einzige
Unterchied, der zwischen dem anatomischen Bild des Labyrinthes
eines neugeborenen Tieres, das den Reflex eben nochnichtaufweist,
und dem eines solchen, dasdenselben zum ersten Male eben erkennan lasst, ist der, dass beim ersteren noch ein Zusammenhang zwischen Cortischem Organ und Cortischer Membran besteht, beim
letzteren dagegen dieser Zusammenhang bereits gelost oder gelockert ist." Their observation is quite different from mine. In my case
the papilla spiralis shows in the development of its constituent
elements pretty large differences between the not-hearing and
hearing rats. Therefore it seems probable that the changes in the
growth and form of the papilla just before the first appearance of
the special function, take place very quickly. Also we cannot
agree to then* statement concerning the relation of the membrana
tectoria to the papilla spiralis. In our preparations there is
still a connection of the membrane with the terminal frame of the
lamina reticularis through a thick thread in the cochlea of the
rat which could hear (fig. 8) and also in that of the rat which
could not hear (fig. 7).
 
This is a point on which opinions differ. While one opinion,
represented by Kishi ('07) and others, is to the effect that this
connection remains through life, the other, represented by Kolliker('67) and others, asserts the membrane projects free in the
endolymph. I have never seen this connection in the adult
cochlea, nor have I found such a connection of the membrane
with the hairs of the hair cells, as Shambaugh ('10) described in
the pig. In the young rats, at fifteen days for example, we very
often see upon the terminal frame the broken remainder of this
connecting thread. Whether this break arises through natural
development or is the result of artificial manipulation it is hard
to say. At any rate, Held's assertion ('90), that in an animal
capable of hearing the membrana tectoria is never connected
 
 
 
154 ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
with the papilla spiralis, is not supported by my observation.
That the freeing of the outer zone of the membrane is not absolutely necessary for the mediation of auditory impulses is
demonstrated in the cochlea of birds, as shown by Hasse ('66),
Retzius ('84), Sato ('17), and others. In these forms the membrane remains through life attached to the epithelial ridge.
 
My results agree with those of Hardesty ('15) on this point,
though he obtained a tectorial membrane which floats free in
the endolymph with its outer zone. Lane ('17) studied the correlation between the structure of the papilla spiralis and the
appearance of hearing in the albino rat, but his description is
brief and does not touch on this relation of the papilla to the
tectorial membrane.
 
Thus the inception of hearing does not coincide with the
detachment of the tectorial membrane from the papilla spiralis,
but with the development of each constituent of the papilla
spiralis and the membrane tectoria, as has been described. As
these changes occur first at the base and then pass to the apex,
the animal can perceive at first only the sounds of high pitch.
One or two days later development is complete in all the turns,
and then the rat can hear the sounds of lower pitch also. Thus
the process of the development of the cochlea does not support
the ' telephone theory' of audition, but on the contrary agrees with
the conclusion that the papilla in different locations in the turns
of the cochlea responds to sounds of a definite pitch, as Wittmaack ('07), Yoshii ('09), Hoessli ('12), and others have shown
by experimental studies on the mammals.
 
Concerning the exact age of the first appearance of the function
in the rat, there are several different statements. Lane ('17)
found no response to sound before the twelfth day after birth,
and on the sixteenth day he reports hearing well established.
Kreidl and Yanase ('07) state that hearing begins in the rat at
from twelve to fourteen days. My rats responded usually at
ten to twelve days, but one at nine days. These differences
depend in all probability on the vigor of the young during the
first days of postnatal life, and it seems probable that exceptionally well-nourished young might develop precociously in this
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT 155
 
respec t. The intensity of the stimulus is important in determining
the hearing reflex, as Small ('99) has stated. In my cases the
young rats responded very evidently to intense sounds, while
they reacted weakly or not at all to those which were faint.
Thus only the intense sounds were perceived by the rat of nine
days.
 
Conclusions
 
1. The hearing reflex was never obtained in rats less than
nine days of age.
 
2. At nine days a single rat, one of five in a litter, responded to
a sharp sound like clapping the hands and to a whistle of high
pitch; the other four did not respond. At the tenth day some
of the four reacted, and at the twelfth day all could hear.
 
3. The hearing reflex probably occurs early in young rats
that are vigorous and well nourished.
 
4. To obtain the first hearing reflexes it is necessary to have
rather strong sounds of high pitch.
 
5. A comparison of the histological structure of the cochlea
in rats of nine days, one of which could hear and the other could
not, shows clear differences in its development of the cochlea.
These consist not in the detachment of the tectorial membrane
from the papilla spiralis, but in the degree of differentiation of
the constituents of the papilla. The tectorial membrane is
connected in both cases at its outer end with the terminal frame
of the lamina reticularis by a thick thread. The papilla is more
differentiated in the hearing rat in several characters. The
tectorial membrane has reached with its outer end the outermost
row of the outer hair cells, but in the not-hearing rat it has not
yet reached the second row of the cells.
 
6. The form of the papilla and its relation to the surrounding
structures, especially to the tectorial membrane, are in the hearing
rat at nine days very similar to those in the rat at twelve days
of age, though there are some differences between them in absolute size.
 
7. The freeing of the tectorial membrane from the papilla
spiralis is not necessary to the appearance of the hearing reflex,
 
 
 
156 ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
but the differentiation of the papilla, its shifting inward, its
change in form and position under the membrana tectoria, appear
to be important.
 
8. Since the papilla develops from the base toward the apex, it
first reaches in the lower turn a high degree of differentiation,
and this part first begins to function. Therefore the rat can
hear only sounds of high pitch when it first responds.
 
9. This result accords with that well-known fact that the
papilla in the lower turn responds to sounds of a high pitch,
while in the upper turn it responds to sounds of low pitch.
 
III. ON THE GROWTH OF THE LARGEST NERVE CELLS
IN THE GANGLION VESTIBULARE
 
Material and technique
 
The material used for the present study was in a great part the
same that was employed for the studies reported in chapter 1,
with the addition of some new specimens as shown in table 114
and table 94. In the slides obtained in the radial vertical section
we see the vestibular ganglion cells situated in a single group
at the radix of the cochlea (Fig. 3 G. V.). As four ears were used
in each age group, four cell groups were examined at each age.
Besides these fourteen age groups, six rats used for cross-sections,
in chapter 1, were also included.
 
The measurements were made in the same way and under
the same conditions as those described earlier for the cells of
the spiral ganglion. Since the ganglion vestibulare consists of
two parts, the ganglion vestibulare superius and inferius, the ten
largest cells were taken from each part and the results averaged.
 
Observations
 
By way of introduction I wish to say a word about equilibration
in the young rat. The young just born crawl over on each other
and seem to attempt to find the mothers nipples. They turn
the head to and fro and roll over on the flanks, belly, or back.
While resting they take their normal position or lie on the side.
When turned on their backs they endeavor to regain the normal
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
157
 
 
 
position. The fore legs are of more use than the hind in making
readjustments. The tails hang down between the hind legs.
 
TABLE 114
 
Data on rats used for the study of the cells of the ganglion vestibulare (radial section).
 
See also table 94
 
 
 
AOB
 
 
BOOT
WEIGHT
 
 
BODY
LENGTH
 
 
BEX
 
 
BIDE
 
 
AUDITOHT
RESPONSE
 
 
days
 
 
grams
 
 
mm.
 
 
 
 
 
 
 
 
1
 
 
5
 
 
44
 
 
9
 
 
R.
 
 
 
 
 
 
 
4
 
 
44
 
 
9
 
 
R.
 
 
 
 
 
 
 
5
 
 
48
 
 
d 1
 
 
R. L.
 
 
 
 
 
3
 
 
9
 
 
60
 
 
<?
 
 
R. L.
 
 
 
 
 
 
 
8
 
 
56
 
 
9
 
 
R. L.
 
 
 
 
 
6
 
 
10
 
 
64
 
 
a
 
 
R.
 
 
 
 
 
 
 
10
 
 
64
 
 
9
 
 
R. L.
 
 
 
 
 
 
 
11
 
 
62
 
 
(7
 
 
R.
 
 
 
 
 
9
 
 
11
 
 
67
 
 
<?
 
 
R. L.
 
 
+
 
 
 
 
9
 
 
58
 
 
9
 
 
R.
 
 
 
 
 
 
 
10
 
 
57
 
 
tf
 
 
R.
 
 
 
 
 
12
 
 
13
 
 
70
 
 
d 1
 
 
R. L.
 
 
+
 
 
 
 
12
 
 
68
 
 
9
 
 
R.
 
 
+
 
 
 
 
15
 
 
72
 
 
c?
 
 
R.
 
 
+
 
 
15
 
 
13
 
 
74
 
 
d"
 
 
R. L.
 
 
+
 
 
 
 
14
 
 
75
 
 
9
 
 
R. L.
 
 
+
 
 
20
 
 
30
 
 
.96
 
 
d 1
 
 
R. L.
 
 
+
 
 
 
 
28
 
 
94
 
 
c?
 
 
R. L.
 
 
+
 
 
25
 
 
34
 
 
101
 
 
9
 
 
R. L.
 
 
+
 
 
 
 
34
 
 
100
 
 
d 1
 
 
R. L.
 
 
+
 
 
50
 
 
58
 
 
121
 
 
9
 
 
R. L.
 
 
+
 
 
 
 
43
 
 
104
 
 
(f
 
 
R. L.
 
 
+
 
 
100
 
 
146
 
 
176
 
 
c?
 
 
L.
 
 
+
 
 
 
 
103
 
 
154
 
 
9
 
 
L.
 
 
+
 
 
 
 
101
 
 
152
 
 
9
 
 
R. L.
 
 
+
 
 
150
 
 
154
 
 
184
 
 
9
 
 
R. L.
 
 
+
 
 
 
 
189
 
 
191
 
 
c?
 
 
R.
 
 
+
 
 
 
 
199
 
 
192
 
 
d 1
 
 
R.
 
 
+
 
 
260
 
 
137
 
 
162
 
 
9
 
 
R.
 
 
+
 
 
 
 
140
 
 
171
 
 
9
 
 
R. L.
 
 
+
 
 
 
 
134
 
 
178
 
 
9
 
 
R.
 
 
' +
 
 
367
 
 
205
 
 
202
 
 
rf
 
 
L.
 
 
+
 
 
 
 
170
 
 
182
 
 
9
 
 
L.
 
 
+
 
 
 
 
179
 
 
196
 
 
9
 
 
R. L.
 
 
+
 
 
546
 
 
282
 
 
222
 
 
d 1
 
 
R. L.
 
 
+
 
 
 
 
227
 
 
204
 
 
d 1
 
 
R. L.
 
 
+
 
 
 
At three days they move and crawl very actively. They
tend to assume the normal position. When rolled over on the
back or side they succeed in regaining the normal position in
 
 
 
158
 
 
 
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
 
 
a few seconds. When six days old the rats have fairly well
coordinated movements. They use their fore and hind legs
effectively and in the same way. When the mother 's body touches
them they respond quickly by searching for the nipples.
 
At nine days they move much more quickly and the movements
are well coordinated. .Though the eyes are still closed, they
 
 
 
TABLE 115
 
Diameters of the cells and their nuclei in the ganglion vestibulare in radial vertical section
 
(Chart 43)
 
 
 
AGE
 
 
BODY
WEIGHT
 
 
DIAMETERS IN M
 
 
CELL BODY
 
 
NUCLEUS
 
 
Long
 
 
Short
 
 
Computed
 
 
Long
 
 
Short
 
 
Computed
 
 
days
 
 
grams
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
 
 
5
 
 
21.2
 
 
19.5
 
 
20.3
 
 
12.4
 
 
11.1
 
 
11.7
 
 
3
 
 
9
 
 
23.7
 
 
22.2
 
 
22.9
 
 
12.5
 
 
11.6
 
 
12.0
 
 
6
 
 
11
 
 
24.0
 
 
22.1
 
 
23.0
 
 
12.3
 
 
11.9
 
 
11.9
 
 
9
 
 
10
 
 
24.8
 
 
23.0
 
 
23.9
 
 
12.5
 
 
11.6
 
 
12.0
 
 
12
 
 
13
 
 
24.9
 
 
23.0
 
 
23.9
 
 
12.5
 
 
11.7
 
 
12.1
 
 
15
 
 
13
 
 
24.8
 
 
23.0
 
 
23.9
 
 
12.5
 
 
11.6
 
 
12.0
 
 
20
 
 
27
 
 
25.0
 
 
23.3
 
 
24.1
 
 
12.3
 
 
11.6
 
 
11.9
 
 
25
 
 
34
 
 
25.2
 
 
23.6
 
 
24.4
 
 
12.5
 
 
11.8
 
 
12.1
 
 
50
 
 
50
 
 
25.6
 
 
23.6
 
 
24.5
 
 
12.5
 
 
11.6
 
 
12.0
 
 
100
 
 
112
 
 
25.5
 
 
23.9
 
 
24.7
 
 
12.8
 
 
11.9
 
 
12.3
 
 
150
 
 
174
 
 
25.4
 
 
23.5
 
 
24.4
 
 
12.8
 
 
11.6
 
 
12.2
 
 
260
 
 
138
 
 
25.8
 
 
23.4
 
 
24.6
 
 
12.4
 
 
11.7
 
 
12.0
 
 
367
 
 
184
 
 
26.2
 
 
24.9
 
 
25.5
 
 
12.9
 
 
11.8
 
 
12.3
 
 
546
 
 
255
 
 
26.5
 
 
24.2
 
 
25.3
 
 
12.8
 
 
11.8
 
 
12.2
 
 
Ratios 1
 
-367 days
 
 
 
 
 
 
1 1.3
 
 
 
 
 
 
1:1.1
 
 
1546 "
 
 
 
 
 
 
1.2
 
 
 
 
 
 
:1.0
 
 
15367 "
 
 
 
 
 
 
1.1
 
 
 
 
 
 
:1.0
 
 
 
crawl toward the object sought. When turned over on the back
they regain the normal position immediately. While resting they
lie on their bellies with all the legs spread well apart.
 
Twelve-day-old rats, though the eyes are still closed, go to
and fro actively with good coordination, but are somewhat slower
than the adults. The body loses its fetal red color through the
development of the first hairs. After this period the rats do
not differ greatly from the adult in their general behavior.
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
159
 
 
 
The growth changes in the ganglion cells of the ganglion vestibulare.
In table 115 (chart 43) are given the values for the diameters
of the cell bodies and their nuclei in the largest cells of the ganglion vestibulare. At the bottom of the last column for the cell
body and for the nucleus, respectively, are recorded the ratios at
1 to 367, 1 to 546, and 15 to 367 days. The last ratio was taken
 
 
 
25
 
a
 
20
15
10
 
 
 
*GEDAYSH
 
 
 
 
 
 
 
25
 
 
 
50
 
 
 
5O 1OO 2OO 30O 4OO 5OO
 
 
 
Chart 43 The diameter of the largest cell bodies and of the nuclei from
the ganglion vestibulare. table 115.
 
Cell bodies. -.-.-.-.-. Nuclei.
 
to facilitate a comparison with the data in table 118 which begin
at 15 days.
 
Looking at the ratios of the cell bodies and of their nuclei
from 1 to 546 days, it appears that the ganglion cells increase 1.2
in diameter, while their nuclei have only a very slight increase,
and therefore the ratio is 1 : 1.0. This increase in the cell bodies
is continuous from birth to old age, but after fifteen days is
very slow. In the nucleus we see a slight increase at the earlier
 
 
 
160 ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
ages, after which the values are nearly constant. This means
that after birth the size of the cell bodies and their nuclei does
not increase so much as do those of the spiral ganglion cells,
or, expressed in another way, the cells in the vestibular ganglion
have developed earlier than those of the spiral ganglia and at
birth have already attained nearly their full size.
 
On the comparison of the diameter of the cell bodies and their
nuclei in the nerve cells of ihe ganglion vestibulare according to sex.
For this purpose twelve age groups of albino rats were used.
In seven cases we have two cochlea in each group in the same sex,
in which the average value is recorded. In table 116 are entered
the values for these diameters and at the foot of the table the
data are analysed. They reveal no evidence of a significant
difference in the diameters according to sex.
 
On the comparison of the diameters in the cell bodies and nuclei
of the nerve cells in the ganglion ves ibulare according to side. For the
present study fourteen age groups were employed. As indicated
in table 117, the data in five instances are based on the average
of two cochleas of the same side. Table 117 enables us to make
the comparison of the diameters of the cell bodies and their
nuclei on both sides, and the analysis of the data given at the
bottom of the table shows that there is no difference in these
characters according to side.
 
On the morphological changes in the cells of the vestibular ganglion.
Figure 14 illustrates semi-diagrammatically the ganglion cells
in the vestibular ganglion of the albino at birth, 20 and 367 days
of age. These figures, as in the ganglion spirale, have been
magnified 1000 times and the absolute values of the diameters
are given in table 115.
 
As seen in figure 14, both the cell body and the nucleus are at
birth already well developed and more precocious in their development than the cells in any of the other cerebrospinal ganglia
thus far examined. The cytoplasm is relatively abundant and
the Nissl bodies are present, though both of these characters
become more marked later.
 
The nucleus is also large, the chromatin somewhat differentiated
and the so-called 'Kernfaden' often occur. Generally speaking,
 
 
 
 
 
 
I Day
 
 
 
20 Days
 
 
 
14
 
 
 
366 Days
 
 
 
Fig. 14 Showing setrii-diagrammatically the size and the morphological changes in
the ganglion cells in the ganglion vestibulare of the albino rat at the age of 1, 20 and 366
days. All cell figures have been magnified 1000 diameters.
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
161
 
 
 
therefore, the cells have the characteristics of the mature elements
though they stain less deeply than in the adult. At twenty days
of age the cell body is enlarged and fully mature. The Nissl
 
TABLE 116
 
Comparison of the diameters of the cells and their nuclei in the ganglion vestibidare
 
according to sex
 
 
 
AGE
 
 
BODY
WEIGHT
 
 
NUMBER OF
RATS
 
 
8EX
 
 
COMPUTED DIAMETERS
 
 
Cell body
 
 
Nucleus
 
 
days
 
 
grams
 
 
 
 
 
 
 
 
 
 
1
 
 
6
 
 
2
 
 
f
 
 
20.8
 
 
11.9
 
 
 
 
 
 
 
 
9
 
 
19.9
 
 
11.5
 
 
3
 
 
9
 
 
2
 
 
tf
 
 
21.7
 
 
11.8
 
 
 
 
8
 
 
2
 
 
9
 
 
23.8
 
 
12.2
 
 
6
 
 
11
 
 
2
 
 
tf
 
 
22.7
 
 
11.9
 
 
 
 
10
 
 
2
 
 
9
 
 
23.1
 
 
12.1
 
 
9
 
 
11
 
 
1
 
 
d*
 
 
23.8
 
 
12.5
 
 
 
 
9
 
 
1
 
 
9
 
 
23.8
 
 
12.1
 
 
12
 
 
15
 
 
1
 
 
cf
 
 
24.4
 
 
12.2
 
 
 
 
12
 
 
1
 
 
9
 
 
23.1
 
 
11.9
 
 
15
 
 
13
 
 
2
 
 
cf
 
 
24.3
 
 
12.2
 
 
 
 
13
 
 
2
 
 
9
 
 
23.4
 
 
11.9
 
 
20
 
 
30
 
 
1
 
 
cf
 
 
24.7
 
 
11.9
 
 
 
 
19
 
 
1
 
 
9
 
 
24.6
 
 
12.6
 
 
25
 
 
34
 
 
2
 
 
d"
 
 
24.4
 
 
11.9
 
 
 
 
34
 
 
2
 
 
9
 
 
24.4
 
 
12.4
 
 
50
 
 
43
 
 
2
 
 
cT
 
 
26.1
 
 
12.4
 
 
 
 
58
 
 
2
 
 
9
 
 
22.6
 
 
11.4
 
 
100
 
 
146
 
 
1
 
 
<?
 
 
26.3
 
 
12.8
 
 
 
 
103
 
 
1
 
 
9
 
 
23.4
 
 
12.6
 
 
150
 
 
194
 
 
2
 
 
rf 1
 
 
24.4
 
 
12.5
 
 
 
 
154
 
 
2
 
 
9
 
 
24.4
 
 
12.0
 
 
365
 
 
205
 
 
1
 
 
<f
 
 
24.2
 
 
11.7
 
 
 
 
170
 
 
1
 
 
9
 
 
24.6
 
 
12.1
 
 
Average for male
 
 
24.0
 
 
12.1
 
 
Average for female
 
 
23.4
 
 
12.1
 
 
Males larger
 
 
6
 
 
7
 
 
Females larger
 
 
3
 
 
5
 
 
Males and females equal
 
 
3
 
 
 
 
 
 
bodies are more differentiated and the nucleus is mature, though
it shows only a slight increase in size.
 
At 367 days the histological structures appear much as at
twenty days, but the diameters of both the cell body and the
nucleus have very slightly increased. This is in contrast to
the change which occurs in the cells of the spiral ganglion.
 
 
 
162
 
 
 
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
 
 
In order to study the form of the cells of the ganglion vestibulare
the measurements also were made on the cross-sections. Table
 
 
 
TABLE 117
 
 
 
Comparison of the diameters of the cells and their nuclei in the ganglion vestibulare
according to side
 
 
 
AGE
 
 
BODY
WEIGHT
 
 
NUMBER
OF RATS
 
 
SIDE
 
 
COMPUTED DIAMETERS
 
 
Cell body
 
 
Nucleus
 
 
days
 
 
grams
 
 
 
 
 
 
 
 
 
 
1
 
 
4
 
 
1
 
 
R.
 
 
20.1
 
 
12.0
 
 
 
 
5
 
 
1
 
 
L.
 
 
22.0
 
 
12.5
 
 
3
 
 
9
 
 
2
 
 
R.
 
 
23.0
 
 
11.8
 
 
 
 
 
 
 
 
L.
 
 
22.6
 
 
12.3
 
 
6
 
 
10
 
 
1
 
 
R.
 
 
23.2
 
 
12.1
 
 
 
 
 
 
 
 
L.
 
 
23.5
 
 
12.0
 
 
9
 
 
11
 
 
1
 
 
R.
 
 
25.1
 
 
12.3
 
 
 
 
 
 
 
 
L.
 
 
23.8
 
 
12.5
 
 
12
 
 
15
 
 
1
 
 
R.
 
 
24.4
 
 
12.2
 
 
 
 
13
 
 
1
 
 
L.
 
 
25.1
 
 
12.5
 
 
15
 
 
13
 
 
2
 
 
R.
 
 
24.2
 
 
12.2
 
 
 
 
 
 
 
 
L.
 
 
23.6
 
 
11.9
 
 
20
 
 
30
 
 
1
 
 
R.
 
 
24.7
 
 
11.9
 
 
 
 
 
 
 
 
L.
 
 
23.5
 
 
11.4
 
 
25
 
 
34
 
 
2
 
 
R.
 
 
23.9
 
 
12.1
 
 
 
 
 
 
 
 
L.
 
 
24.9
 
 
12.2
 
 
50
 
 
50
 
 
2
 
 
R.
 
 
23.1
 
 
11.6
 
 
 
 
 
 
 
 
L.
 
 
25.6
 
 
12.3
 
 
100
 
 
101
 
 
1
 
 
R.
 
 
25.0
 
 
12.0
 
 
 
 
 
 
 
 
L.
 
 
24.8
 
 
11.7
 
 
150
 
 
199
 
 
1
 
 
R.
 
 
25.1
 
 
12.8
 
 
 
 
154
 
 
1
 
 
L.
 
 
25.4
 
 
12.5
 
 
263
 
 
140
 
 
1
 
 
R.
 
 
26.5
 
 
12.3
 
 
 
 
 
 
 
 
L.
 
 
25.1
 
 
12.4
 
 
368
 
 
179
 
 
1
 
 
R.
 
 
27.2
 
 
12.6
 
 
 
 
 
 
 
 
L.
 
 
26.2
 
 
13.0
 
 
546
 
 
255
 
 
2
 
 
R.
 
 
26.0
 
 
12.4
 
 
 
 
 
 
 
 
L.
 
 
24.6
 
 
12.0
 
 
Average right side
 
 
24.4
 
 
12.2
 
 
Average left side
 
 
24.3
 
 
12.2
 
 
Right larger
 
 
8
 
 
6
 
 
Left larger
 
 
6
 
 
8
 
 
 
118 (chart 44) shows the results. Looking at the ratios of 15 to
371 days, we see the same rate of increase in the cell bodies and
the nuclei as that in the radial section; i.e., in the cell bodies
1 : 1.1 and in the nuclei 1 : 1.0. Comparing the diameters at each
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
163
 
 
 
TABLE 118
 
Diameters of the cell bodies and their nuclei in the ganglion vestibulare, on crosssection (chart 44)
 
 
 
 
 
 
 
DIAMETERS M
 
 
AOK
 
 
BOOT
WEIGHT
 
 
CELL BODY
 
 
NUCLEUS
 
 
 
 
 
 
Long
 
 
Short
 
 
Computed
 
 
Long
 
 
Short
 
 
Computed
 
 
days
 
 
grams
 
 
 
 
 
 
 
 
 
 
 
 
 
 
15
 
 
20
 
 
25.1
 
 
22.8
 
 
23.9
 
 
12.4
 
 
11.6
 
 
12.0
 
 
20
 
 
27
 
 
25.2
 
 
23.4
 
 
24.3
 
 
12.5
 
 
11.7
 
 
12.1
 
 
25
 
 
39
 
 
25.2
 
 
24.0
 
 
24.6
 
 
12.3
 
 
12.0
 
 
12.1
 
 
100
 
 
95
 
 
26.6
 
 
24.7
 
 
25.6
 
 
12.8
 
 
11.8
 
 
12.3
 
 
150
 
 
169
 
 
26.7
 
 
24.7
 
 
25.7
 
 
13.0
 
 
11.7
 
 
12.3
 
 
371
 
 
220
 
 
26.8
 
 
25.3
 
 
26.0
 
 
12.8
 
 
11.8
 
 
12.3
 
 
Ratio 15-371 days 1:1.1
 
 
 
 
 
 
1 :1.0
 
 
 
25
 
 
 
20
 
 
 
15
 
 
 
10
 
 
 
25
 
 
 
50
 
 
 
50 10O 20O 300 40O 5OO
 
 
 
Chart 44 The diameters of the cell bodies and of their nuclei from the
ganglion vestibulare, after fifteen days (cross-section), table 118.
Cell bodies. -.-.-.-.-. Nuclei.
 
 
 
164
 
 
 
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
 
 
age in both the radial and cross-sections, they are almost the
same, with a slight tendency for the cells in the cross-section to
give higher values, which suggests that the long axes of these
cells tend to lie in the plane of the section.
 
On the nucleus-plasma relations of the ganglion cells in the ganlion vestibulare. In table 119 are entered the computed diameters
of the cell bodies and their nuclei in the radial section, and in
the last column the ratios of the volume of the nucleus to that of
the cytoplasm obtained by the method previously given. As
 
TABLE 119
 
Nucleus-plasma ratios of the cells in the. ganglion vestibulare radial vertical section
 
 
 
 
 
 
 
COMPUTED DIAMETERS M
 
 
AGE
 
 
BODY WEIGHT
 
 
Cell body
 
 
Nucleus
 
 
Nucleus-plasma
ratios
 
 
days
1
 
 
grams
5
 
 
20.3
 
 
11.7
 
 
1 :4.2
 
 
3
 
 
9
 
 
22.9
 
 
12.0
 
 
:5.9
 
 
6
 
 
11
 
 
23.0
 
 
11.9
 
 
:6.2
 
 
9
 
 
10
 
 
23.9
 
 
12.0
 
 
:6.9
 
 
12
 
 
13
 
 
23.9
 
 
12.1
 
 
:6.7
 
 
15
 
 
13
 
 
23.9
 
 
12.0
 
 
:6.9
 
 
20
 
 
27
 
 
24.1
 
 
11.9
 
 
:7.3
 
 
25
 
 
34
 
 
24.4
 
 
12.1
 
 
:7.2
 
 
50
 
 
50
 
 
24.5
 
 
12.0
 
 
:7.5
 
 
100
 
 
112
 
 
24.7
 
 
12.3
 
 
:7.1
 
 
150
 
 
174
 
 
24.4
 
 
12.2
 
 
:7.0
 
 
260
 
 
138
 
 
24.6
 
 
12.0
 
 
:7.6
 
 
367
 
 
184
 
 
25.5
 
 
12.3
 
 
:7.9
 
 
546
 
 
255
 
 
25.3
 
 
12.2
 
 
:7.9
 
 
 
seen, the ratio is at birth relatively large, 1 : 4.2, and this increases
with age, in the earlier stages considerably, but in the later, less
rapidly. In the oldest age group it is largest, 1: 7.9.
 
On the cross-section the nucleus-plasma ratio is also progressive
and the increase is very regular (table 120). Comparing the
ratios in the radial with those in the cross-sections, they are
found to be nearly the same at fifteen twenty and twenty-five days,
but at the later ages those in the cross-sections are somewhat
larger than in the radial. It is difficult to determine whether
the ratios on the cross-section are really larger or whether the
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
105
 
 
 
result depends on the fact that the number of the cells here
measured is only one-fourth of that measured in the radial
section, and hence fewer cells of smaller size were included.
At any rate, these ganglion cells in both the radial and crosssections of the cochlea appear to grow at about the same rate.
The statistical constants for these cells and their nuclei are
given in tables 121 and 122.
 
Discussion
 
The nerve cells in the ganglion vestibulare are, as seen from
the above description, already well developed at birth both in
size and histological structure. After that time they grow con
TABLE 120
 
Nucleus-plasma ratios of cells of the ganglion vestibulare, in cross-section
 
 
 
 
 
 
 
DIAMETERS COMPUTED M
 
 
 
 
BOOT
 
 
 
 
AGE
 
 
WEIGHT
 
 
 
 
 
 
 
 
 
 
Cell body
 
 
Nucleus
 
 
Nucleus-plasma
 
 
 
 
 
 
 
 
 
 
ratios
 
 
days
 
 
grams
 
 
 
 
 
 
 
 
15
 
 
20
 
 
23.9
 
 
12.0
 
 
1 :6.9
 
 
20
 
 
27
 
 
24.3
 
 
12.1
 
 
:7.1
 
 
25
 
 
39
 
 
24. ti
 
 
12.1
 
 
:7.4
 
 
100
 
 
95
 
 
25.6
 
 
12.3
 
 
:8.0
 
 
150
 
 
169
 
 
25.7
 
 
12.3
 
 
:8.1
 
 
371
 
 
220
 
 
26.0
 
 
12.3
 
 
:8.4
 
 
 
tinuously but slowly so long as followed. The increase from 1
to 546 days in the ratios of the diameters is in the cell body
1: 1.3, in the nucleus 1: 1.1, and is therefore very small. In the
cerebrospinal ganglion cells and in the cells of the cerebral
cortex, studied in the albino rat, there is no case which shows such
a small rate of increase between birth and maturity. The following table 123 shows the ratios of increase which have been found.
 
It is to be noted that for the cells of the seventh spinal ganglion and the spinal cord, the ratios were taken from 17 to 360
days. If we had the ratios from 1 to 360 days, they would be
without question much larger.
 
There are a few measurements on the size of the ganglion
cells in the vestibular ganglion of various animals in the liter
 
 
166
 
 
 
ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
 
 
ature. Schwalbe ('87) and Alexander ('99) report measurements
on these cells in several animals, but for the reasons already
given when considering the diameters of the cells in the ganglion
spirale, the values obtained by the authors are not repeated here.
 
TABLE 121
 
Giving the mean, standard deviation and coefficient of variability, with their respective probable errors, for the diameters of the cells in the ganglion vestibulare,
in radial-vertical section
 
 
 
AGE
 
 
CELL
NUCLEUS
 
 
MEAN
 
 
STANDARD
DEVIATION
 
 
COEFFICIENT OF
VARIABILITY
 
 
days
1
 
 
Cell
 
 
20.1 0.16
 
 
1.46 0.11
 
 
7.3 0.55
 
 
 
 
Nucleus
 
 
11.7 0.11
 
 
0.99 0.07
 
 
8.5 0.64
 
 
3
 
 
Cell
 
 
22.6 0.14
 
 
1.33 0.10
 
 
5.9 0.44
 
 
 
 
Nucleus
 
 
11.9 0.07
 
 
0.63 0.05
 
 
5.3 0.40
 
 
6
 
 
Cell
 
 
22.8 0.13
 
 
1.23 0.09
 
 
5.4 0.41
 
 
 
 
Nucleus
 
 
11.9 0.05
 
 
0.43 0.03
 
 
3.6 0.27
 
 
9
 
 
Cell
 
 
23.6 0.16
 
 
1.48 0.11
 
 
6.3 0.48
 
 
 
 
Nucleus
 
 
12.0 0.0<9
 
 
0.82 0.06
 
 
6.8 0.52
 
 
12
 
 
Cell
 
 
23.6 0.14
 
 
1.28 0.10
 
 
5.4 0.41
 
 
 
 
Nucleus
 
 
12.0 0.06
 
 
. 59 . 04
 
 
4.9 0.37
 
 
15
 
 
Cell
 
 
23.6 0.13
 
 
1.21 0.09
 
 
5.1 0.39
 
 
 
 
Nucleus
 
 
12.1 0.06
 
 
0.60 0.05
 
 
5.0 0.38
 
 
20
 
 
Cell
 
 
23.9 0.16
 
 
1.54 0.11
 
 
6.5 0.49
 
 
 
 
Nucleus
 
 
11.9 0.10
 
 
0.90 0.07
 
 
7.6 0.55
 
 
25
 
 
Cell
 
 
24.2 0.16
 
 
1.48 0.11
 
 
6.1 0.46
 
 
 
 
Nucleus
 
 
12.1 0.08
 
 
0.74 0.06
 
 
6.1 0.46
 
 
50
 
 
Cell
 
 
24.1 0.30
 
 
2.80 0.21
 
 
11.6 0.88
 
 
 
 
Nucleus
 
 
11.8 0.09
 
 
0.86 0.06
 
 
7.3 0.55
 
 
100
 
 
Cell
 
 
24.3 0.20
 
 
1.86 0.14
 
 
7 . 7 . 58
 
 
 
 
Nucleus
 
 
12.2 0.09
 
 
0.86 0.06
 
 
7.0 0.53
 
 
150
 
 
Cell
 
 
24.1 0.18
 
 
1.70 0.13
 
 
7.1 0.53
 
 
 
 
Nucleus
 
 
12.2 0.09
 
 
0.83 0.06
 
 
6.8 0.52
 
 
260
 
 
Cell
 
 
24.3 0.26
 
 
2.45 0.18
 
 
10.1 0.76
 
 
 
 
Nucleus
 
 
11.9 0.07
 
 
0.67 0.05
 
 
5.6 0.42
 
 
367
 
 
Cell
 
 
25.2 0.22
 
 
2.07 0.16
 
 
8.2 0.62
 
 
 
 
Nucleus
 
 
12.3 0.09
 
 
0.88 0.07
 
 
7.2 0.54
 
 
546
 
 
Cell
 
 
25.0 0.19
 
 
1.80 0.14
 
 
7.2 0.54
 
 
 
 
Nucleus
 
 
12.1 0.09
 
 
0.81 0.06
 
 
6.7 0.50
 
 
 
On the differences between the growth of the cells in the ganglion
spirale and ganglion vestibulare. The foregoing discussion has
made plain that the vestibular ganglion cells grow not only in
size, but also in histological structure very much before birth,
while after birth they grow slowly though continuously. On the
other hand, the spiral ganglion cells are relatively immature at
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT
 
 
 
167
 
 
 
birth, but in the earlier stages after birth grow very rapidly,
reach at twenty days their maximum size, and then diminish
slowly. This great difference in the course of growth is probably related to the maturity of the functions of the animal.
 
TABLE 122
 
Giving the mean, standard deviation and coefficient of variability with their respective
probable errors for the diameters of the cells in the ganglion
vestibulare on cross-section
 
 
 
AGE
 
days
 
 
CELL
NUCLEUS
 
 
MEAN
 
 
STANDARD
DEVIATION
 
 
COEFFICIENT OF
VARIABILITY
 
 
15
 
 
Cell
 
 
23.8 0.21
 
 
1.00 0.15
 
 
4.2 0.58
 
 
 
 
Nucleus
 
 
12.0 0.12
 
 
0.55 0.08
 
 
4.6 0.69
 
 
20
 
 
Cell
 
 
23.9 0.20
 
 
0.92 0.14
 
 
3.9 0.58
 
 
 
 
Nucleus
 
 
12.1 0.06
 
 
0.30 0.05
 
 
2.5 0.37
 
 
25
 
 
Cell
 
 
24.4 0.20
 
 
0.94 0.14
 
 
3.9 0.58
 
 
 
 
Nucleus
 
 
12.1 0.03
 
 
0.16 0.02
 
 
1.3 0.20
 
 
100
 
 
Cell
 
 
25.4 0.32
 
 
1.51 0.23
 
 
5.9 0.90
 
 
 
 
Nucleus
 
 
12.3 0.15
 
 
0.72 0.11
 
 
5.9 0.88
 
 
150
 
 
Cell
 
 
25.6 0.20
 
 
0.94 0.14
 
 
3.7 0.55
 
 
 
 
Nucleus
 
 
12.4 0.09
 
 
0.42 0.06
 
 
3.4 0.51
 
 
371
 
 
Cell
 
 
25.9 0.41
 
 
1.91 0.29
 
 
7.4 1.11
 
 
 
 
Nucleus
 
 
12.3 0.06
 
 
0.26 0.04
 
 
2.1 0.32
 
 
 
TABLE 123
Ratios of diameters between the ages given.
 
 
 
 
 
CEREBRAL CORTEX
 
 
 
 
DONALDSON AND
 
 
 
 
(SUGITA, '18)
 
 
 
 
NAOABAKA. '18
 
 
CELL
GROUP
 
 
LAMINA
 
 
LAMINA
 
 
OA88ERIAN
 
 
SPIRAL
 
 
VESTIBULAR
 
 
7TH
 
 
EFFERENT
 
 
 
 
PYHA
 
GANO
 
GANGLION
 
 
GANGLION
 
 
GANGLION
 
 
SPINAL
 
 
SPINAL
 
 
 
 
MIDIS
 
 
LIONARIS
 
 
NITTONO
 
 
WADA
 
 
WADA
 
 
GANGLION
 
 
CORD
 
 
 
 
 
 
 
 
C20)
 
 
 
 
 
 
 
 
CELLS
 
 
Age
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
days
 
 
1-730
 
 
1-730
 
 
1-330
 
 
1-546
 
 
1-546
 
 
17-360
 
 
17-360
 
 
Cell
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
body
 
 
1 :1.6
 
 
1 : 1.6
 
 
1 : 1.69
 
 
1 : 1.6
 
 
1 :1.2
 
 
1 :1.3
 
 
1 :1.2
 
 
Nucleus
 
 
: 1.5
 
 
: 1.5
 
 
: 1.20
 
 
: 1.2
 
 
: 1.0
 
 
: 1.2
 
 
: 1.2
 
 
 
As a consequence, in the nucleus-plasma ratio there is also
a large difference between the cells in the two ganglia. Table 124
shows this.
 
The ratio at birth in the ganglion vestibulare is large as compared with that in the ganglion spirale, but the increase in this ratio
 
 
 
168 ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
at 546 days is relatively slight as compared with what takes
place in the cells of the ganglion spirale. It appears, therefore,
that the cells in the vestibular ganglion are at birth in a more
mature condition.
 
As to the correlation between the development of the ganglion
cells and the equilibrium function, we have noted that the albino
rats, even just after birth, show some sense of equilibrium,
though the movements are lacking in coordination. With advancing age the balance of the body is held much better and all
the movements gradually become coordinated. The histological
structure and the size of the cells at birth suggest that they are
functional at that time, and the later increase in the volume
and maturity of the cells is accompanied by a corresponding
 
TABLE 124
 
 
 
 
 
GANGLION
VESTIBULARE
 
 
GANGLION
SPIRALE
 
 
Nucleus-plasma ratio at one day
Nucleus-plasma ratio at 546 days
 
 
1 :4.8
:7.9
 
 
1 : 1.3
 
:4.2
 
 
 
increase in the functional development. When the tactile sense
is well developed and the eyes open equilibrium is almost perfected.
It is a well-known fact that these two senses have very intimate relations to the maintenance of equilibrium. In this case,
as we might expect, the early development of a function is
accompanied by an early maturing of the neural mechanism
on which it depends.
 
Conclusions (for the ganglion vestibulare)
 
1. The measurements were taken on the largest nerve cells
of the ganglion vestibulare in the radial section of the cochlea,
and the developmental changes during portnatal growth studied
in fourteen age groups, comprising four ears in each group.
Further, in six age groups the cell size was determined in crosssections. The results have been given n tables 115 and 118
and charts 43 and 44.
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT 169
 
2. The computed diameter at birth is 20.3 [x for the cell body
and 11.7 ^ for the nucleus, and at 546 days, 25.3 and 12.2 n,
respectively. Therefore the cells at birth are comparatively large
and increase in size very slowly, but the increase is continuous.
 
3. The increase in the ratio of the cell body is as 1 : 1.3, of the
nucleus as 1 : 1.1. We have between the same age limits no such
small rate of increase in any other cerebrospinal ganglion studied
in the albino rat. This small ratio indicates that the cells in
the vestibular ganglion are well developed at birth.
 
4. We find no appreciable difference in the diameters of the
cell bodies or the nuclei according either to sex or side.
 
5. Morphologically, the cells at birth are well differentiated.
The form of the cells is ovoid.
 
6. The nucleus-plasma ratios are large at birth and increase
regularly with age.
 
7. Comparing the development of the function of equilibrium
with the growth of the cells, we see that these are correlated.
 
Final summary
 
This study is concerned with the age changes in the organ
of Corti and the associated structures. The changes in the
largest nerve cells which constitute the spiral ganglion and the
vestibular ganglion, respectively, have also been followed from
birth to maturity. On pages 116 to 124 are given the summary
and discussion of the observations on the growth of the tympanic
wall of the ductus cochlearis.
 
The conclusions reached from the study of the largest nerve cells
in the ganglion spirale appear on pages 143 to 145. On pages
155 and 156 are presented the results of the study on the correlation
between the response to sound and to the conditions of the cochlea.
 
Finally, the observations on the growth of the largest cells in
the ganglion vestibu'are are summarized on pages 168 and 169.
 
It is not necessary to again state in detail the conclusions
reached in the various parts of this study.
 
At the same time, if we endeavor to obtain a very general
picture of the events and changes thus described, this may be
sketched as follows:
 
 
 
170 ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
Within the membranous cochlea there occurs a wave of growth
passing from the axis to the periphery as shown in figures 4 to 13.
The crest or highest point of the tissue mass appears at birth
near the axis, in the greater epithelial ridge, and then progressively shifts toward the periphery, so that at maturity it is in
the region of the Hensen cells. With advancing age the hair
cells come to lie more and more under the tectorial membrane
and the pillar cells seem to shift toward the axis.
 
At from 9 to 12 days the tunnel of Corti appears and the rat
can hear.
 
All of these changes occur first in the basal turn and progress
toward the apex. The mature relations are established at about
twenty days. There are thus two waves of change in the membranous cochlea, from the axis to the periphery and the other
from the base to the apex. The rat can usually hear at twelve
days of age or about three days before the eyes open.
 
The largest cells in the ganglion spirale are very immature at
birth, reach their maximum at twenty days, and after that diminish in size, slightly but steadily. The rat hears, therefore,
before these cells have reached their full size.
 
The largest cells in the vestibular ganglion are precocious
and remarkably developed, even at birth. They cease their
rapid growth at about fifteen days of age, but increase very
slightly though steadily throughout life.
 
 
 
GROWTH OF THE INNER EAR OF ALBINO RAT 171
 
 
 
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174 ANATOMICAL AND PHYSIOLOGICAL STUDIES ON
 
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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

Tokujiro Wada

Wistar Institute Of Anatomy And Biology

Contents

Introduction

Material

Technique

I. On the growth of the cochlea

A. On the growth of the radial distance between the two spiral ligaments

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

1. Membrana tectoria

2. Membrana basilaris

3. The radial distance between the habenula perforata and the inner corner of the inner pillar cell at base

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

5. The radial basal breadth of the outer pillar cell (including the outer pillar)

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

7. The greatest height of the greater epithelial ridge (dem grossen Epithelwulst Bottcher's s. Organon Kollikeri) resp. of the inner supporting cells

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

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

10. Vertical distance from the membrana basilaris to the summit of the pillar cells

11. The greatest height of the tunnel of Corti

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

13. The greatest height of Hensen's supporting cells

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

15. Lengths of the inner and outer pillar cells

16. Inner and outer hair cells

17. Deiter's cells

18. Summary and discussion

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

Observations

Discussion

Conclusions

II. Correlation between the inception of hearing and the growth of the cochlea

Observation 146

Discussion 152

Conclusions 155

III. On the growth of the largest nerve cells in the ganglion vestibulare

Material and technique 156

Observations 156

Discussion 165

Conclusions 168

Final Summary

Literature Cited

Introduction

Since Alphonse Corti, in 1851, published his famous work on the cochlea of mammals, studies on this organ have been made by many authors and have produced fairly concordant results. Concerning the postnatal growth of the internal ear, however, systematic studies are lacking. Especially is there no investigation, so far as I know, on the growth of the nerve cells in the ganglion spiral, not even in the great work of Retzius. ('84).

It was the special object of these studies, therefore, to follow the growth of the cells forming the spiral ganglion from birth to maturity and to correlate the changes in them with the appearance of the functional responses and with the structural changes in the membranous cochlea. In the course of this investigation studies were made also on the cells of the ganglion vestibulare, in order to see whether these cells differed in their growth from the cells in the spiral ganglion. Both of these ganglia are situated in the course of nervus acusticus, but have, as is well known, entirely different functions.

Thus determinations have been made on the diameters of the cells of the ganglion spirale and of their nuclei at different ages; of the nucleus-plasma ratios and of then* growth in relation to those of other portions of the membranous cochlea. For the cells of the vestibular ganglion similar determinations were also made. Finally, these results have been compared with those obtained from the study of other craniospinal ganglia in the albino rat.

In presenting my results I shall begin with a description of the changes in the larger portions of the membranous cochlea and pass from these to the cell elements themselves, and then to the observations on the ganglion cells and to the correlation between hearing and the growth of the cochlea.


Material

For the present studies forty male and thirty female albino rats were used, representing every phase of postnatal growth and having approximately standard body weights. These were all from the colony of The Wistar Institute, and were sometimes from the same, and sometimes from different litters.

At first all these rats were tested for their ability to hear and their equilibrium, and it was ascertained that after about twelve days of age, or somewhat earlier, they responded positively to the test for hearing. Such examinations were deemed necessary, to make certain that the rats used were normal.

I have arranged the animals thus tested in fourteen groups according to age, each group having five individuals in it. Serial sections from all these cochleas were made by methods to be given later. Most of them were in the plane of the vertical axis of the cochlea, but some were at right angles to it.

From the former I selected four ears in each group for the study of the growth of the cochlea. For the study of the growth of the ganglion vestibulare, I have used for the most part the same specimens. For the study of the sections at right angles to the vertical axis of the cochlea, sections from one ear of each group were used.

Technique

In order to obtain good preparations of this delicate organ, the method of vital fixation (injection under anaesthesia) was used. The method employed, and which proved almost ideal, was that introduced by Metzner and Yoshii ('09), Siebenmann and Yoshii ('08) and somewhat improved by Sato ('17). After the animals had been tested to make sure that they were quite normal, the fixing solution was injected through the aorta under ether. The brain was then carefully removed, care being taken not to drag the trunk of the nervus acusticus, as noted by Nager ('05), and the bulla tympanica was opened to allow the further penetration of the fluid.


The bony labyrinth with its surrounding bones was then placed in the fixing solution for two weeks, the fluid being renewed every day.

The fixing solution which I used consists, according to Yoshii ('09), of

10 per cent formol 74 parts

M tiller's fluid 24 parts

Glacial acetic acid 2 parts

According to Tadokoro and Watanabe ('20), this solution is one of the best, ranking with that of Wittmaack ( '04, '06) and that of Nakamura ('14).

This injection method is sometimes difficult to apply to very young rats on account of the small size and the delicacy of the vessels. When injection failed in very young animals, then immediately the head was cut off and put directly in the fixing fluid. Owing to the incomplete calcification of the very young cochlea, the fixing solution enters rapidly and fixes the deepseated organs in good condition. Since the parts of the internal ear are not yet well developed in the very young rats, they do not suffer from this method of fixation as do the older cochleas.

Indeed, no differences are to be seen between the sections prepared by vital fixation and by decapitation in very young rats.

For decalcification I have employed the following solution during three days, renewing it every day.

Decalcifying fluid

5 per cent aqueous nitric acid 49 parts

10 per cent formol 49 parts

Glacial acetic acid 2 parts

After the specimens had been washed in running water for three days, they were passed through the alcohols from 50 to 97 per cent. For the imbedding I have used 'parlodion' with good results. Here it is to be mentioned that all the cochleas were treated in the same way, even unossified cochlea being passed through the decalcifying fluid, so that there should be absolutely no differences in treatment.


The next important matter is the determination of the plane of the section. For the measurement of growth changes it was necessary to obtain corresponding sections from the several cochleas. In an organ like that of Corti, which changes in its details from one end to the other, however, it is very difficult to accomplish this, but I believe that I have overcome most of the difficulties.

After much testing, I found that a section parallel to the under surface of os occipitale in the fronto-occipital direction runs nearly exactly parallel to the axis of the modiolus of the cochlea. In order to get the same direction from right to left, I have taken as the standard the transverse plane of the under surface of the os occipitale, controlling the direction of the section with a magnifying glass. Thus nearly the same radial direction and nearly corresponding places in the cochlea were obtained in the several series of sections. This makes possible a trustworthy comparison of the measurements and drawings.

The cross-section of the cochlea was gotten by making the plane of the cut transverse to the axis of the modiolus. To get the corresponding levels is difficult. At first I divided all the serial sections by 2^, which is the number of complete turns in the cochlea of the albino rat. Next, from the number of the slides representing each turn, I determined nearly the corresponding level in the cochlea according to age.

All the sections were 10;x in thickness. The sections were stained for the most part with haematoxylin and eosin, but sometimes by Heidenhain's iron haematoxylin or the iron haematoxylin and Van Gieson's stain. For the measurements, however, only the sections stained with haematoxylin and eosin were used.

For the examination of the larger parts of the cochlea and their relations, the sections were projected on a sheet of paper by the Leitz-Edinger projection apparatus, at a magnification of exactly a hundred diameters, and the outline of the image accurately traced. The remaining measurements of the ganglion cells and the smaller portions of the cochlea were made directly under the microscope. The measurements made on the tympanic wall of the cochlea are somewhat complicated, but by the aid of figures 1 and 2 they may be explained. In figure 1 lines 1-1, 1-1'. 2-2, 3-3 indicate, respectively, the height of the arch of Corti, of the tunnel of Corti, of the papilla spiralis (Huschke) at the third series of outer hair cells, and of Hensen's supporting cells, respectively, above the plane of the membrana basilaris.

Lines 4-4' which are the extensions of the surface of the lamina reticularis and of the membrana basilaris, subtend the angle 8.

To get the exact measurements of the radial breadth of the membrana tectoria is very difficult, if not impossible, because it is sinuous in its course; moreover, it differs in thickness from point to point. Therefore, it has been variously described by different authors. Intra vitam fixation tends to prevent distortion. We divide the membrana tectoria, figure 1, into two portions, the first or inner (7-7'-9-9') and the second or outer (5-5 '-7-7') or outer zones of Retzius; each of these is again divided in two at 6-6' and 8-8', as shown in figure 1.

I have measured the radial distance of each portion and added all four together. This total approximates the natural radial breadth of this membrane, and since the sections have all been prepared in the same way and examined by the same method, the relations during growth can be followed.

In figure 2, 1-1 and 2-2, mark the length of the inner and outer pillar cells, respectively, from base to the point, which is situated just under their junction. It is to be noted here that the term ' pillar cell ' here applies to the pillars in the strict sense and does not include the associated cells.

Distances 3 and 7 in figure 2 show the basal breadth of the inner and outer pillars, respectively. The former is identical with the distance between the habenula perforata and the outer corner of the inner pillar after the inner corner of the pillar has reached the habenula perforata, but there is some difference between the two distances in very young rats. Distance 4 is that between the habenula perforata and the inner corner of the outer pillar; distance 5 is that between the habenula perforata and the outer corner of the outer pillar. The latter represents at the same time the radial breadth of the zona arcuata of the membrana basilaris.



Fig. 1 Showing the localities for the measurement of each part of the tympanic wall of ductus cochlearis in the albino rat, 100 days old radial vertical section. 1-1, height from the basal plane to the surface of pillar cells; 1-1', greatest height of the tunnel of Corti; 2-2, height of papilla spiralis at the third series of the outer hair cells; 3-3, height of Hensen's supporting cells; 4~4', 4 indicates the extension of the membrana basilaris and 4' the extension of the lamina reticularis. The two lines subtend the angle 0. The radial breadth of the membrana tectoria is taken as the sum of the four segments between the lines 5-5' and 9-9'.

Fig. 2 Showing the method of measurement for several parts of the tympanic wall of the ductus cochlearis in the albino rat, 100 days old. 1-1, length of inner pillar cell without head; 2-2, length of outer pillar cell without head Distance 3 shows radial distance between habenula perforata and the outer corner of inner pillar at base after twelve days of age this equals the radial basal breadth of inner pillar. Distance 4, radial distance between habenula perforata and the inner corner of outer pillar at base. Distance 5, radial breadth of the zona arcuata (Deiters') of membrana basilaris, and at the same time it indicates radial distance between habenula perforata and the outer corner of outer pillar at base. Distance 6, radial distance between the outer corner of inner pillar and the inner corner of outer pillar at base. Distance 7, radial basal breadth of outer pillar. Distance 8, radial distance between the habenula perforata and outer corner of inner pillar cell at base. Distance 9, radial basal breadth of the outer pillar cell. Distance 10, radial breadth of zona pectinata of the membrana basilaris. Distance 11, radial breadth of entire membrana basilaris.

Fig. 3 Showing the general outline of the cochlea in the radial vertical section albino rat, 100 days of age.



Abbreviations

Line 1, 1, distance between two basal L.L.S., limbus laminae spiralis

spiral ligaments L.S., ligamentum spirale

Line 2, 2, distance between two apical L.S.O., lamina spiralis ossea

spiral ligaments M.T., membrana tectoria

7, first turn N.C., nervus cochlearis

II, second turn O., bone

///, third turn P.S., papilla spiralis

IV, fourth turn S., stria vascularis

D.C., ductus cochlearis S.T., scala tympani

G.S., ganglion spirale S.V., scala vestibuli G.V., ganglion vestibulare


Distance 6 is that between the outer corner of the inner pillar and the inner corner of the outer pillar. Distance 8 is that between the habenula perforata and the outer corner of the inner pillar cell. Distance 9 shows the radial basal breadth of the outer pillar cell plus the outer pillar. Distance 11 shows the radial breadth of the membrane basilaris comprising distance 5 (zona arcuata) and 10, which is the radial breadth of the zona pectinata of the membrana basilaris.

Final summary

This study is concerned with the age changes in the organ of Corti and the associated structures. The changes in the largest nerve cells which constitute the spiral ganglion and the vestibular ganglion, respectively, have also been followed from birth to maturity. On pages 116 to 124 are given the summary and discussion of the observations on the growth of the tympanic wall of the ductus cochlearis.

The conclusions reached from the study of the largest nerve cells in the ganglion spirale appear on pages 143 to 145. On pages 155 and 156 are presented the results of the study on the correlation between the response to sound and to the conditions of the cochlea.

Finally, the observations on the growth of the largest cells in the ganglion vestibu'are are summarized on pages 168 and 169.

It is not necessary to again state in detail the conclusions reached in the various parts of this study.

At the same time, if we endeavor to obtain a very general picture of the events and changes thus described, this may be sketched as follows:


170 ANATOMICAL AND PHYSIOLOGICAL STUDIES ON

Within the membranous cochlea there occurs a wave of growth passing from the axis to the periphery as shown in figures 4 to 13. The crest or highest point of the tissue mass appears at birth near the axis, in the greater epithelial ridge, and then progressively shifts toward the periphery, so that at maturity it is in the region of the Hensen cells. With advancing age the hair cells come to lie more and more under the tectorial membrane and the pillar cells seem to shift toward the axis.

At from 9 to 12 days the tunnel of Corti appears and the rat can hear.

All of these changes occur first in the basal turn and progress toward the apex. The mature relations are established at about twenty days. There are thus two waves of change in the membranous cochlea, from the axis to the periphery and the other from the base to the apex. The rat can usually hear at twelve days of age or about three days before the eyes open.

The largest cells in the ganglion spirale are very immature at birth, reach their maximum at twenty days, and after that diminish in size, slightly but steadily. The rat hears, therefore, before these cells have reached their full size.

The largest cells in the vestibular ganglion are precocious and remarkably developed, even at birth. They cease their rapid growth at about fifteen days of age, but increase very slightly though steadily throughout life.

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