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=An Atlas Of The Medulla And Midbrain=
 
[[File:Sabin1901 titlepage.jpg|right|400px]]
'''AN ATLAS OF THE MEDULLA AND MIDBRAIN'''
[[File:Florence Sabin 1938.jpg|thumb|alt=Florence Rena Sabin (1871 - 1953)|link=Embryology History - Florence Sabin|Florence Rena Sabin (1871-1953)]]
 
By [[Embryology History - Florence Sabin|Florence R. Sabin]]  
By [[Embryology History - Florence Sabin|Florence R. Sabin]]  






A LABORATORY MANUAL
A Laboratory Manual


ILLUSTRATED WITH SEVEN COLORED PLATES, ONE BLACK PLATE AND FIFTY-TWO FIGURES
Illustrated With Seven Colored Plates, One Black Plate And Fifty-Two Figures




EDITED BY
Edited By




Line 22: Line 21:




BALTIMORE, MD., U. S. A.  
Baltimore, Md., U. S. A.  


THE FRIEDENWALD COMPANY
The Friedenwald Company


PUBLISHERS
Publishers


1901  
1901  
Line 32: Line 31:




COPYRIGHT, 1901,  
Copyright, 1901,  
BY FLORENCE R. SABIN
By Florence R. Sabin




THE FRIEDENWALD COMPANY
The Friedenwald Company
BALTIMORE, MD M U. S. A.  
Baltimore, Md M U. S. A.  


{{Historic Disclaimer}}
{{Historic Disclaimer}}
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==Editor's Preface==
==Editor's Preface==


This Atlas is planned to meet the practical need of some quick and simple, yet full and reliable, means of aiding the student to  
This Atlas is planned to meet the practical need of some quick and simple, yet full and reliable, means of aiding the student to obtain, from a few sections (or from a series of sections), a reasonably clear idea of the important central relay-station of the brain  
obtain, from a few sections (or from a series of sections), a reasonably clear idea of the important central relay-station of the brain  
here presented. (Though representing the human brain, the atlas can be applied to the study of the brains of lower mammals.)  
here presented. (Though representing the human brain, the atlas  
can be applied to the study of the brains of lower mammals.)  


The time allotted to a course in Neurology is generally so short;  
 
the sections to be studied exhibit such great special complexity of  
The time allotted to a course in Neurology is generally so short; the sections to be studied exhibit such great special complexity of  
structure, due to the presence and association of many different  
structure, due to the presence and association of many different  
centres in the narrow limits of the region; and the descriptions in  
centres in the narrow limits of the region; and the descriptions in  
Line 56: Line 53:
shown in their preparations, without spending more time in the  
shown in their preparations, without spending more time in the  
effort than is reasonable.  
effort than is reasonable.  


We believe, and a number of well-known teachers in several of  
We believe, and a number of well-known teachers in several of  
Line 62: Line 60:
stated above; and will save the student much time for real study,  
stated above; and will save the student much time for real study,  
now often spent in getting started.  
now often spent in getting started.  


Supplied with these excellent drawings of the reconstruction, showing for the first time accurately and satisfactorily structures  
Supplied with these excellent drawings of the reconstruction, showing for the first time accurately and satisfactorily structures  
to be studied, the student can quickly compare his own sections  
to be studied, the student can quickly compare his own sections with the figures of the Atlas and find the parts there clearly  
with the figures of the Atlas and find the parts there clearly  
designated and explained.  
designated and explained.  


Again, if, as is usually the case, a student has only a few cross
 
-J-Tiio -narnrvn + Vi a A+laa with if.a 4-8 fiomrPS of
Again, if, as is usually the case, a student has only a few cross-sections through this region the Atlas with its 48 figures of sections.






At the urgent solicitation of Professor Ph. Stohr,  
At the urgent solicitation of Professor Ph. Stohr, of Wiirzburg, Germany, Dr. F Ziegler, of Freiburg, Germany, is considering the reduplication of the model on which this atlas is based. It is expected that such models, from his studio, will be available within  
of Wiirzburg, Germany, Dr. F Ziegler, of Freiburg,  
Germany, is considering the reduplication of the model  
on which this atlas is based. It is expected that  
such models, from his studio, will be available within  
the year .  
the year .  


Line 93: Line 87:
==Editor's Preface==
==Editor's Preface==


This Atlas is planned to meet the practical need of some quick The need of
This Atlas is planned to meet the practical need of some quick and simple, yet full and reliable, means of aiding the student to obtain, from a few sections (or from a series of sections), a reasonably clear idea of the important central relay-station of the brain here presented. (Though representing the human brain, the atlas can be applied to the study of the brains of lower mammals.)
and simple, yet full and reliable, means of aiding the student to  
obtain, from a few sections (or from a series of sections), a reasonably clear idea of the important central relay-station of the brain  
here presented. (Though representing the human brain, the atlas  
can be applied to the study of the brains of lower mammals.)  


The time allotted to a course in Neurology is generally so short;
the sections to be studied exhibit such great special complexity of
structure, due to the presence and association of many different
centres in the narrow limits of the region; and the descriptions in
text-books or lectures are commonly so detailed, or so general or
diagrammatic; that many students get but hazy ideas of what is
shown in their preparations, without spending more time in the
effort than is reasonable.


We believe, and a number of well-known teachers in several of  
The time allotted to a course in Neurology is generally so short; the sections to be studied exhibit such great special complexity of structure, due to the presence and association of many different centres in the narrow limits of the region; and the descriptions in text-books or lectures are commonly so detailed, or so general or diagrammatic; that many students get but hazy ideas of what is shown in their preparations, without spending more time in the effort than is reasonable.
our large universities have agreed in this opinion, that this little
Atlas will offer a valuable and new remedy for the difficulties
stated above; and will save the student much time for real study,
now often spent in getting started.  


Supplied with these excellent drawings of the reconstruction, its use with , sections.


showing for the first time accurately and satisiactorily structures
We believe, and a number of well-known teachers in several of our large universities have agreed in this opinion, that this little Atlas will offer a valuable and new remedy for the difficulties stated above; and will save the student much time for real study, now often spent in getting started.
to be studied, the student can quickly compare his own sections
with the figures of the Atlas and find the parts there clearly
designated and explained.  


Again, if, as is usually the case, a student has only a few crosssections through this region, the Atlas, with its 48 figures of sections cut in two planes and drawn to resemble actual preparations,
furnishes a good supplementary series of sections for comparison.


It is thus easy to understand the many sections which are not
Supplied with these excellent drawings of the reconstruction, showing for the first time accurately and satisiactorily structures to be studied, the student can quickly compare his own sections with the figures of the Atlas and find the parts there clearly designated and explained.
through particularly well-marked points usually figured in textbooks; and it is possible to get a very satisfactory idea of any structure, by turning to the two series figured, to the colored plates
and to the index,
with sections of Tracts in the Spinal Cord may be more readily understood and Spinal Cord. 'traced forward into the brain with the aid of this manual.
The arrangement The text not only describes, in a convenient manner and fully,
' everything figured in the reconstruction; but the paragraphs of  
small print, and others referred to in the headings and index, explain just how to compare sections with the model, and how to trace
nerve-fibre tracts or masses of gray matter, from section to section through this region.  


The importance When it is realized that this model represents that part of the
f the Braku brain in which the nuclei of origin of all the true cranial nerves
are found; that association tracts between these centres are here
included; that the cells and fibre-tracts are brought into intimate
association, from their central position, with those of the Spinal
Cord, Cerebellum, and Forebrain; the usefulness of the Atlas to
the Anatomist, Physiologist, Pathologist, and Psychologist, whether
in the laboratory or in connection with lectures and demonstrations,
may be seen.


supplementary A short list of text-books and journals has been included, to
Again, if, as is usually the case, a student has only a few crosssections through this region, the Atlas, with its 48 figures of sections cut in two planes and drawn to resemble actual preparations, furnishes a good supplementary series of sections for comparison.
" permit the tracing of certain tracts of nerve-fibres further up into
the higher brain centres or down into the cord, and to encourage the
student to seek information as to the many and varied sides of  
Neurology from reliable sources where more extensive references
are to be found.  


The Editor wishes to explain that his participation in this Atlas
is confined to the suggestion of publishing the original research in
the present modified new form, and to assistance in a considerable
rearrangement of the text and index to facilitate ready reference.
He has urged this publication in order to furnish the student, in a
new and especially available form, a valuable guide to the ready


interpretation of his preparations.  
It is thus easy to understand the many sections which are not through particularly well-marked points usually figured in textbooks; and it is possible to get a very satisfactory idea of any structure, by turning to the two series figured, to the colored plates and to the index.


HENRY Mo E. KNOWER.
Tracts in the Spinal Cord may be more readily understood and Spinal Cord traced forward into the brain with the aid of this manual.
ANATOMICAL LABORATORY,


JOHNS HOPKINS UNIVERSITY.  
The text not only describes, in a convenient manner and fully, everything figured in the reconstruction; but the paragraphs of small print, and others referred to in the headings and index, explain just how to compare sections with the model, and how to trace nerve-fibre tracts or masses of gray matter, from section to section through this region.




When it is realized that this model represents that part of the brain in which the nuclei of origin of all the true cranial nerves are found; that association tracts between these centres are here included; that the cells and fibre-tracts are brought into intimate association, from their central position, with those of the Spinal Cord, Cerebellum, and Forebrain; the usefulness of the Atlas to the Anatomist, Physiologist, Pathologist, and Psychologist, whether in the laboratory or in connection with lectures and demonstrations, may be seen.


AUTHOR'S PREFACE.


A description and the plates of a reconstruction of the medulla
A short list of text-books and journals has been included, to permit the tracing of certain tracts of nerve-fibres further up into the higher brain centres or down into the cord, and to encourage the student to seek information as to the many and varied sides of Neurology from reliable sources where more extensive references are to be found.
oblongata of the new-born babe was published in the " Contributions to the Science of Medicine," dedicated to William Henry
Welch. 1 The model was built in the Anatomical Laboratory of
the Johns Hopkins University at the suggestion of Dr. Franklin
P. Mall and Dr. Lewellys F. Barker. It was the original thought
that such a reconstruction would not only show graphically for the
first time the form and relations of the tracts and nuclei, but that
it would simplify for the student of anatomy a region both complex and difficult. The shape of the tracts in the cord was well
known, the forms of the internal capsule in the brain could be
fairly well imagined, but the tracts between the cord and brain
were too complex to give mental pictures without the aid of a
model. The suggestion has been made by Dr. H. Me E. Knower,
of the Anatomical Laboratory of the Johns Hopkins Medical
School, that the description of the model be put into a more convenient form for the student; by means of fuller references to  
the plates and sections; by a rearrangement of contents to make
the location in the model of any set of serial sections or any single
section of the region an easy matter; by adding a full index; and  
by a list of literature containing a few of the most important
references valuable to the student at the beginning of a study
of the central nervous system of man or the mammals. I am indebted to him for the arrangements for this edition.  


I wish to thank Dr. John Hewetson for the material which
made the model possible. Both series were unbroken, and so admirably prepared that any omissions in the model are due not to the material, but to the nature of the structures in question.
I am greatly indebted to Mr. Max Broedel for the beautiful illustrations of the model. They are so accurate and clear as to be
equal in value to the model itself. It is through the kindness of
Dr. Henry M. Hurd that the plates of these drawings can be used
for the present edition. Dr. Franklin P. Mall controlled the construction of the model, Dr. Lewellys F. Barker its study. I acknowledge with thanks their unfailing help and interest.


The Editor wishes to explain that his participation in this Atlas is confined to the suggestion of publishing the original research in the present modified new form, and to assistance in a considerable rearrangement of the text and index to facilitate ready reference. He has urged this publication in order to furnish the student, in a new and especially available form, a valuable guide to the ready interpretation of his preparations.




1 Model of the Medulla, Pons and Midbrain of a New-born Babe, by Florence R. Sabin. Contributions to the Science of Medicine, and vol. ix of the Johns Hopkins Hospital Reports.
Henry Mc E. Knower. Anatomical Laboratory,


Johns Hopkins University.


==Author's Preface==


==Contents==
A description and the plates of a reconstruction of the medulla oblongata of the new-born babe was published in the " Contributions to the Science of Medicine," dedicated to William Henry Welch.<ref> Model of the Medulla, Pons and Midbrain of a New-born Babe, by Florence R. Sabin. Contributions to the Science of Medicine, and vol. ix of the Johns Hopkins Hospital Reports.</ref> The model was built in the Anatomical Laboratory of the Johns Hopkins University at the suggestion of Dr. Franklin P. Mall and Dr. Lewellys F. Barker. It was the original thought that such a reconstruction would not only show graphically for the first time the form and relations of the tracts and nuclei, but that it would simplify for the student of anatomy a region both complex and difficult. The shape of the tracts in the cord was well known, the forms of the internal capsule in the brain could be fairly well imagined, but the tracts between the cord and brain were too complex to give mental pictures without the aid of a model. The suggestion has been made by Dr. H. Me E. Knower, of the Anatomical Laboratory of the Johns Hopkins Medical School, that the description of the model be put into a more convenient form for the student; by means of fuller references to the plates and sections; by a rearrangement of contents to make the location in the model of any set of serial sections or any single section of the region an easy matter; by adding a full index; and by a list of literature containing a few of the most important references valuable to the student at the beginning of a study of the central nervous system of man or the mammals. I am indebted to him for the arrangements for this edition.


Chapter I.


Introductory
I wish to thank Dr. John Hewetson for the material which made the model possible. Both series were unbroken, and so admirably prepared that any omissions in the model are due not to the material, but to the nature of the structures in question. I am greatly indebted to Mr. Max Broedel for the beautiful illustrations of the model. They are so accurate and clear as to be equal in value to the model itself. It is through the kindness of Dr. Henry M. Hurd that the plates of these drawings can be used for the present edition. Dr. Franklin P. Mall controlled the construction of the model, Dr. Lewellys F. Barker its study. I acknowledge with thanks their unfailing help and interest.
I wish to thank Dr. John Hewetson for the material which made the model possible. Both series were unbroken, and so admirably prepared that any omissions in the model are due not to the material, but to the nature of the structures in question.
I am greatly indebted to Mr. Max Broedel for the beautiful illustrations of the model. They are so accurate and clear as to be
equal in value to the model itself. It is through the kindness of
Dr. Henry M. Hurd that the plates of these drawings can be used
for the present edition. Dr. Franklin P. Mall controlled the construction of the model, Dr. Lewellys F. Barker its study. I acknowledge with thanks their unfailing help and interest.


Method Of Using Atlas


Chapter Ii. The Long Tracts.
A. In The Medulla (Medulla Sheet)
B. In The Pons And Midbrain (Lemnisci And Formatio Reticularis)
Chapter Iii. The Columns Of The Spinal Cord.
A. Ventrolateral Column
(A) Ventral Part
(&) Dorsal Part
B. Dorsal Column
Chapter Iv. Cerebellar Peduncles.
Inferior Peduncle, Or Corpus Restiforme
Superior Peduncle, Or Brachium Conjunctivum
Chapter V. The Cerebral Nerves And Their Nuclei. Median Group (Red In Model).
(A) N. Hypoglossus, XII
Nucleus N., XII
(&) N. Abducens, VI
Nucleus N., VI
(C) N. Trochlearis, IV
Nucleus N., Iv 56
(D) N. Oculomotorius, III
Nucleus N., III
Chapter Vi. The Cerebral Nerves And Their Nuclei (Continued). Lateral Group.
A. Motor Nerves (Red In Model)
(A) N. Accessprius, XI
Nucleus N., XI. 
(B) N. Glossopharyngeus Et N. Vagus, Ix And X
Nucleus N., Ix And X
(C) N. Facialis, VII
Nucleus N., VII
(D) N. Trigeminus, V
Nucleus N., V
B. Sensory Nerves (Blue In Model)
(A) N. Glossopharyngeus Et N. Vagus, Ix And X
Nucleus N. , Ix And X
(&) N. Trigeminus, V
Nucleus N., V
(C) N. Vestibuli, Viii
Nuclei N. Vestibuli
(D) N. Cochleae, Viii
Nuclei N. Cochlese
Chapter Vii. The Inferior And Accessory Olives 86
Chapter Viii. The Midbrain.
1. Relation Of Its Structures To The Central Fibre Mass
2. The Nucleus Ruber (Red Nucleus) And Its Capsule
3. The Fasciculus Retroflexus (Meynerti)
4. The Decussatio Tegmenti Dorsalis (Meynerti)
5. The Decussatio Tegmenti Ventralis Of Forel
6. Stratum Album Prof Undum (Deep White Layer)
7. Substantia Centralis Grisea (Central Gray Matter)
8. The Pyramidal Tract
9. Substantia Nigra
Chapter Ix. The Formatio Reticularis Alba And Grisea
General Summary of what Is shown In Reconstruction
References To Literature
==List of Illustrations==
FIGURES : PAGE
1. Transverse Section of the Spinal Cord. Outline 36
2. Diagram of Medial Accessory Olive 91
3-24. Series of Horizontal (frontal) Sections, including Medulla and Midbrain 125-132
25-51. Series of Transverse Sections from the Cord to the Midbrain. .133-145
52. Diagram of the Model giving Levels of Sections here Figured 146
PLATES following page 146
I. The Inferior Olive.
II. View of the Lateral Surface of the Reconstruction.
III. View of the Dorsal Surface of the Reconstruction.
IV. First Dissection of the Reconstruction. Lateral view, showing
Fibre Tracts, &c., and the Sensory Nuclei of Cerebral Nerves.
V. Second Dissection of the Reconstruction. Lateral view, showing
Fibre Tracts, &c., and Motor Nuclei of Cerebral Nerves.
VI. Third Dissection of the Reconstruction. Lateral view, showing
the Long Tracts of the Medulla.
VII. Fourth Dissection of the Reconstruction. Dorsomedian view,
showing the Long Fibre Tracts as Related to Nuclei of Cerebral Nerves and to other Structures.
VIII. View of the Midbraiu from Above, showing Relations of Fibre Tracts.
==Chapter VII. The Inferior and Accessoey Olives==
1. NUCLEUS OLIVARIS INFERIOE.
inferior " Position. The surface form of the olive, as seen on the uncut
medulla, is shown in all text-books (Fig. 33). Its position in the
reconstruction is seen on Plates n, in and iv. The nucleus itself
extends from the proximal limit of the decussatio pyramidum to
the pons (Fig. 20). It lies in the ventral portion of the medulla
oblongata, lateral to the stratum interolivare lemnisci, from which
it is separated by the root-fibres of the N. hypoglossus and the
median accessory olive. Dorsal to the olive lies the large area of
formatio reticularis in the medulla oblongata, but the lateral and
ventral aspects of the olive are superficial. Opposite the distal half
of the lateral surface is a considerable mass of medullated fibres
belonging to the lateral funiculus of the spinal cord, but only one
small bundle of these fibres extends opposite the proximal half of
the olive (Plate iv).
The dimensions of the olive are as follows: The dorsoventral
diameter 4.48 mm., the transverse 6.5 mm., and the anteroposterior
7.5 mm.
The gray matter of the olive forms a hollow shell with a wrinkled
wall (Fig. 35). In the model it is made nearly solid inasmuch as,
with the magnification used, its walls made strips of wax too thin
to handle. It presents for examination six surfaces dorsolateral,
lateral, ventral, proximal, distal and medial the last surface including the hilus. The dorsolateral surface, as its name indicates,
slopes toward the lateral surface and passes over into it by a gradual
curve. On the other hand, the ventral surface is practically level,
but likewise rounds onto the lateral surface. This corresponds to
the familiar form of the olive in cross-section (Fig. 35).
In Plate i, Fig. 1, is shown a lateral view, including the dorsolateral surface. The general outline of this view is of interest.
The dorsal border is practically level. Starting from the distal
THE INTEBIOB AND ACCESSORY OLIVES 87
end of the nucleus, the outline passes ventralward and forward by
a gradual curve which reaches its most ventral point at the proximal
end of the ventral surface. This will be recognized as the curve
of the olive seen on the uncut medulla. The proximal border is
slightly curved and represents the edge that faces the pons.
The surface of the olive is marked by deep sulci and more shallow grooves, so that the whole suggests the surface of a brain.
From the view of the lateral surface it will be noted that all of these
grooves run in an approximately dorsoventral direction.
The dorsal or dorsolateral surface shows three sulci. They are
approximately parallel and divide the dorsal part of the olive into
four lobes. These sulci are distinguishable from the other grooves
on this surface in being deeper, for they reach down to the opening
of the hilus, as can be seen in Fig. 19. The sulci do not pass
over onto the curve of the lateral surface, which is marked by
comparatively shallow grooves that more or less alternate with the
deep sulci of the dorsolateral surface. From this fact it follows
that the lobes are well marked only in the dorsal portion. It is
evident that transverse sections of the olive would be all comparatively similar over the lateral curve, but would differ on the dorsolateral surface, according as the section passed through a sulcus or
a lobe. This will be clear by comparing Figs. 31 and 32.
Of the four lobes, the first or proximal is the largest (Plate i,
Fig. 1, L. p.). It is subdivided in the dorsal portion by two or
three fairly deep grooves. The first sulcus runs a little obliquely,
the dorsal end being further spinalward than the ventral. The
first lobe has three surfaces (1) a dorsolateral, (2) a proximal and
(3) a mesial. In other words, the first lobe curves around the
proximal end of the nucleus to the mesial surface, so as to enclose
a portion of the hilus. This explains why a cross-section of the
proximal lobe shows the gray matter as a complete ring (Fig. 36).
The first lobe is made up of three convolutions, or gyri, two of
which are seen from the lateral view and the other from the mesial.
The second and third lobes consist each of a single convolution,
or gyrus. They present but one surface, directed dorsolaterally.
At the dorsal border they are comparatively narrow, but broaden
out in joining the lateral surface.
The fourth lobe forms the distal end of the olive and is the
smallest of all, consisting, like the second and third, of a single convolution or gyms. It does not curve around the hilus as does
the first lobe (Fig. 20). Nevertheless, the lobe is placed obliquely,
so that a cross-section of the extreme distal part is a small closed
ring, the same as the cross-section of the proximal lobe.
The surface of the lobes and the sides of the sulci are marked by
small grooves which run in a dorsoventral direction. Indeed, in the
depth of the sulci are small folds in the nuclear wall. These can
be seen in longitudinal section (Fig. 19).
The lateral surface forms the curve of the shell. Its dorsal
margin (Plate i, Fig. 1) is an indistinct line where it curves onto
the dorsolateral surface. Its ventral border makes the curve of
the surface form. This curve or ventral border is so placed that
the distal part of the lateral surface is narrow, that is, the part
opposite the fourth lobe. The greatest breadth of the lateral surface is at the proximal end. The entire surface is covered by
shallow grooves, of which the deepest alternates with the first and
second sulci. It is worthy of note that all of the grooves of this
surface run in a dorsolateral direction, as do those of the dorsolateral surface.
The ventral surface is smaller than the dorsal (Plate i, Fig. 2).
It is for the most part horizontal, but at the spinal end it passes
by a gradual curve onto the distal surface (Fig. 33). In its surface
markings it contrasts with the dorsolateral and lateral surfaces, for
instead of taking a dorsoventral direction, its grooves all radiate out
from a point in the ventral border of the hilus (Plate i, Fig. 2).
This point is opposite the word mesial in the figure. Thus it
happens that while the distal groove runs transversely, as do those
of the dorsolateral surface, the proximal groove runs longitudinally
parallel to the raphe and at right angles to the grooves of the dorsolateral surface.
The grooves of the ventral surface are not marked by secondary
furrows, as are the sulci of the dorsolateral surface. As has been
said, these grooves appear to radiate from a point about the middle
of the ventral border of the hilus. The first or most medial of these
grooves (S. p.) runs directly parallel to the long axis of the olive,
that is, in an anteroposterior direction. It is a deep groove and
extends far dorsalward on the median surface, separating off a
small gyrus from the main lobe. This is seen only on a view of the
mesial surface which, unfortunately, is not given. The second (S. s.) passes obliquely toward the cerebrum and becomes continuous with one of the grooves of the lateral surface. The third (S. t.)
lies still more obliquely and does not leave the ventral surface.
The distal part of the ventral surface is somewhat damaged, inasmuch as the sections were here a little too much decolorized in
preparation, but enough can be made out to say that the grooves
run transversely and are the continuation of the grooves of the
lateral surface.
The medial surface is not given in the plates. It shows the hilus.
From this aspect it can be seen that the ventral part of the olive
makes a floor for the hilus and the dorsal part, a roof (Fig. 33).
The proximal end of the hilus is closed in by the first lobe (Fig. 20).
Opposite each lobe of the surface is a deep groove in the cavity to
which the hilus leads, and the sides of these main grooves are
marked again by grooves which correspond each to one convolution
of the external surface. In brief, the essential points of the form
of the olive are (1) its general shape as a hollow shell, (2) its hilus,
(3) its transverse grooves on the dorsolateral surface, and (4) its
radiating grooves on the ventral surface.
The olives of both sides were modelled in the effort to see if the
fissures above described offered a basis of symmetry. The symmetry proved to be sufficiently apparent to lead one to an emphasis of the differences. The three deep fissures of the external
surface, as well as the three radiating grooves of the ventral aspect,
corresponded in the two lines. The differences consisted in the
relative size of two of the lobes. The first lobe of the right olive
was larger than the corresponding lobe of the other side, while the
fourth lobe of the right side was proportionately smaller. The
term proportionately is accurate, inasmuch as the two olives are of
the same length and the second and third lobes correspond in size
on the two sides. The symmetry of the two olives is shown in
Fig. 19. At this level the fourth lobe of the right side is but a
single fold in the nuclear wall.
It is now necessary to relate the appearance of the sections to the Inferior olive
form of the olive in the model. A typical cross-section, so to speak, in sections,
shows the thin folded wall and the open hilus (Fig 1 . 33). Attention has
already been called to the fact that the form of the wall varies according as a section passes through a sulcus or a lobe (Figs. 32 and 33). It
will be noticed that, inasmuch as the sulci run slightly obliquely, no
one section passes through the entire length of one sulcus. The sulci can be used in determining the symmetry of an olive cut in crosssection. In tracing the olive of the cross series of the same stage, it
is found that the first lobe of one side is larger and the fourth smaller
than the corresponding lobes of the other side, the same peculiarity
that has been noted in the model. I have, however, no method of determining right and left side of either series as compared with a real
medulla.
Sections in a longitudinal direction differ widely from those of the
transverse series; they illustrate the symmetry of the olive, that is they
show the relation of the lobes and sulci and the varying depth of the
sulci and grooves far better than the transverse series (Figs. 16 to 23).
The first section shows the dorsal border of the olive. In the next three
sections the symmetry can be traced, and note made of the relative size
of the first and fourth lobes. The relation of the wall of these two
lobes to cross-sections is evident, that is, the obliquity of the fourth
lobe and the curve of the wall of the first account for the closed circles
at either end in the transverse series. The last three sections pass
through the ventral wall and the direction of the sulci is the point of
special interest.
In the various longitudinal sections it will be noted that there are
groups of cells either as rings or as irregular figures, that are wholly
separate from the main wall; some of these lie within and some without
the hilus (Fig. 19). These can be understood by reference to the transverse series. If, for example, in Fig. 33, a transverse line is drawn
across the dorsal wall of the olive, it will cut off rings of cells, and these
rings will be of two types: (1) a ring from a fold that projects on the
lateral surface, and (2) a ring from a fold that projects into the hilus.
The rings of the first type lie without the hilus and have their outer
margin corresponding to the surface of the olive; the rings of the
second type lie within the hilus and have their inner margin corresponding to the surface of the olive. This is a practical point in modeling
the olive.
Fibres of From this study of the sections it is clear that the fibres of the olive
inferior olive. are non-medullated at birth and hence are not in the model.
3Pf
Median Nucleus oUvaris accessorius medialis. The medial accessory
' olive is an irregular nucleus, much broken by bands of fibres running through it. It lies opposite the main olive, between the interolivary layer of the lemniscus and the root-bundle of the !N".
hypoglossus (Plate v). Its inferior limit extends farther spinalward than the nucleus olivaris inferior, but its proximal does not
reach as far cerebralward. From the view of the lateral surface
(Fig. 2), it consists of. three columns of cells running in a dorsoventral direction. Each of the columns has small separate masses
of cells opposite its dorsal border. The first or distal column is
by far the largest. Its ventral portion is thick and a prominent
process from the distal ventral angle curves around the distal border
of the N". hypoglossus and the main olive (Plate vn). It makes an indentation in the ventral part of the medulla sheet (Plate YI).
At the proximal ventral angle the first column connects with the
second. The dorsal border of the first column shows a spur of
cells from the distal half, while corresponding to the proximal half
is a small separate group of cells. The spur corresponds to the
second indentation on the medulla sheet (Plate vi). The second
column is thin and flat; opposite its dorsal border are two small
masses of cells. The third column is about one-third as broad as
the others; it makes a narrow column of cells, opposite the dorsal
end of which is still another small nucleus.
Dorsal
in sections.
Ventral.
FIG. 2. Diagram of Nucleus olivaris accessorius medialis.
In longitudinal sections these relations are clear. Fig". 20 passes Median
through the three columns near the ventral border. The first, which is accessory olive
clearly the largest, appears curving around the inferior border of the
main olive. The root-fibres of the N. hypoglossus cut through it. The
second and third columns need only be mentioned. Passing dorsalward,
we have the three columns, making groups of cells between the fibres
of the N. hypoglossus and the stratum interolivare lemnisci (Fig. 19).
Fig. 17 shows the scattered groups of cells of the medial-accessory olive.
Cross-section. In Fig. 29, is seen the ventral part of the first column.
This is, however, much better developed in Figs. 30 and 31. In Fig. 32
the second column is present, while in Figs. 33 and 35 the third column
is seen.
The nucleus olivaris accessorius dorsalis is not shown in the
model, but Fig. 15 skows its shape. It varies in shape on the two
sides. The distal portion lies dorsal to the third lobe of the nucleus
olivaris inferior, and the proximal portion corresponds to the second
lobe.
==Chapter VIII. The Midbrain==
1. THE RELATION OF ITS STRUCTURES TO THE CENTRAL FIBRE MASS.
The midbrain has been difficult to model, inasmuch as it is not
easy to give definite outlines to all of its nuclei and fibre-bundles.
The key to the form relations of the region was given in the description of the medial lemniscus. The central fibre mass, including
the medial lemniscus, the superior lemniscus and the lateral part of
the capsule of the red nucleus, is placed obliquely in the midbrain
and divides it into two areas. The medial area contains the red
nucleus, a formatio reticularis area, the nuclei of the oculomotor
and trochlear nerves and the fasciculus longitudinalis medialis
(Plates ni, vn, vni), while the lateral area contains the substantia
nigra, and, later in course of development, the pyramidal tract
(Plate n). In the view from the lateral surface given in Plate n,
the midbrain sheet is shown, with the substantia nigra in place.
In Plate v the substantia nigra has been removed and the complete fibre-sheet is thus revealed. In a third view (Plate iv) the
fibre-sheet itself has been removed and the whole midbrain medial
to it is visible. In the ventral portion is seen the nucleus ruber
and its capsule; dorsal to it is the space for the formatio reticularis,
while toward the median line can be seen the fasciculus longitudinalis medialis, the stratum profundum album of the superior colliculus, together with the nucleus and root-fibres of the oculomotor
nerve. These three views give a general idea of the whole area.
Plate vni shows the midbrain seen from above. The form
relations of the region are (1) the great size of its nuclei, namely,
the nucleus ruber and the substantia nigra and (2) the deflection
of the medial lemniscus, apparently due to the development
of the nucleus ruber. In describing the midbrain, then, the relations of the fibre-sheet will first be considered; secondly, the structures that lie medial to it; and finally, those that lie lateral to it.
The fibre-sheet as a whole has been described in connection with the medial lemniseus, and reference will be made here only to
those parts of it that belong essentially to the midbrain, namely,
the lemniscus superior and the lateral capsule of the red nucleus.
The latter will be considered in connection with that nucleus.
The lemniscus superior is best seen in a lateral view (Plates n superior
and v). Its shape has already been described; it is a triangular
sheet of fibres placed upon the lemniscus medial is. In the model
the only means of distinguishing it from the medial lemniscus lies
(1) in the thinness of the sheet and (2) in the fact that, while the
medial lemniscus passes on beyond the region of the model, and is
therefore shown with a square-cut edge, the lemniscus superior
ends within the limits of the model and has a rounded edge.
The lemniscus superior appears to begin opposite the proximal
part of the pons, where a few of the fibres of the medial lemniscus
seem to radiate from the main bundle, making a fairly thick sheet
at the start, which, however, grows thinner as it becomes wider. A
further point of interest is that the dorsal border of the superior
lemniscus comes to lie adjacent to the capsule of the nucleus
colliculi inferioris.
The transverse series shows many interesting points in regard to the g uper i or
lemniscus superior. In Fig. 40 there is no distinction to be made be- lemniscus
tween the medial and the lateral lemnisci; but by passing farther cere- insectlons bralward to Fig. 42, it becomes evident that the two separate; between
them is an area of fine fibres, those of the lemniscus superior. In Fig.
43 the fibres of the lemniscus superior are passing farther dorsalward.
This shows clearly on the model. The lemniscus superior lies even
farther lateral than the lemniscus lateralis itself. The next section
(Fig. 44) shows interesting relations. The nucleus colliculi inferioris
has almost disappeared. The lemniscus medialis is gradually curving
into its characteristic midbrain position and the superior lemniscus is
making its way to the region just lateral from the capsule of the nucleus of the inferior colliculus. Figs. 46, 47 and 48 take the superior
lemniscus well into the region of the superior colliculus, and here the
fibres are few, fine, and cut in cross-section. The transverse series is
not complete enough to show the proximal limit of the lemniscus
superior. In the longitudinal series, on the other hand, the lemniscus
superior is apparently complete and the sections show that it does not
pass beyond the midbrain (Fig. 12). Three sections will show the relative widths of the lemniscus medialis and the lemniscus superior: (1)
Fig. 16, which shows the lemniscus medialis; (2) Fig. 13, a transition,
and (3) Fig. 12, which shows the lemniscus superior. In this last section, as well as in Fig. 9, the superior lemniscus borders the large area
of gray matter in the superior colliculus and, indeed, appears to have
some relation with its cells. Indeed, there is a closely packed group of cells, almost a definite nucleus, opposite the end of the tract. 1 In
passing still farther dorsalward it becomes impossible to distinguish
the superior lemniscus from the capsule of the nucleus colliculi inf erioris (Fig. 7) ; but in the next section (Fig. 6) is seen the area of the
nuclear capsule without question.
The model bears out closely the description of the relations of
the lemniscus superior given by Forel. 2 If any of its fibres pass
on, it must be those in the ventral part, where the bundle lies adjacent to the lemniscus medialis. On the other hand, the view of
Elechsig, that the superior lemniscus ends in the superior colliculus, is well sustained.
The end of the tract, as seen in the model, is about opposite the
point at which the fasciculus retroflexus of Meynert plunges into
the nucleus ruber.
2. THE NUCLEUS RUBER AND ITS CAPSULE (PLATE iv).
Red nucleus. The nucleus ruber has a capsule of cells and fibres on its dorsal,
lateral and superior surfaces. The spinal surface of the nucleus,
on the other hand, is related (1) to the fibres of the !N". oculomotorius, (2) to the brachium conjunctivum, (3) possibly to some
fibres of the lemniscus medialis. The ventral surface at this stage
lies in a mass of cells which underlies both the nucleus ruber and
the substantia nigra (Plates iv, v and vm). This mass I have
called the lectus or bed of the two nuclei.
The red nucleus will be described first, inasmuch as it makes
so prominent a feature of the midbrain. It is seen from the side
in Plate iv, and from a mesial aspect, in Plate vn. In the latter
view a portion of the superior capsule of the red nucleus has been
removed, as can be seen by comparing with Plates v and vm. The
connection of the brachium conjunctivum with the red nucleus is seen in part on Plate iv, but far better in Plate vin. where other Red nucleus, structures have been sacrificed to show this relation on the right
side of the view. The position of the nucleus ruber in this view is
judged by the shape of its capsule.
1 This is in accord with v. Monakow, C., Experimentelle und pathologisch-anatomische Untersuchungen ueber die Haubenregion, den Sehhuegel und die Regio subthalmica, nebst Beitragen zur Kenntniss friih
erworbener Gross- und Kleinhirn defecte. Arch. f. Psychiat., Berl., Bd.
27 (1895), S. 1-128. On S. 452 in the same volume, he refers to what I
have termed the proximal limit of the lemniscus superior, as the place
where the superior lemniscus and the chief part of the lemniscus fuse.
2 Forel, A., Untersuchungen iiber die Haubenregion un ihre oberen
Verkniipfungen im Gehirne des Menschen und einiger Sangethiere mit
Beitragen zu den Methoden der Gehirnuntersuchung. Arch. f. Psychiat.,
Berl., Bd. VII (1877), S. 393-495.
The nucleus is roughly oval but not regular in shape. It is
placed in the ventral portion of the midbrain, surrounded on its
dorsal, lateral and superior surfaces by a capsule of cells and fibres.
The lemniscus medialis, in passing toward the thalamus, lies adjacent to the dorsolateral angle of the capsule, where the two fibre
masses are practically indistinguishable. Just distal to the red
nucleus, or at least to its dorsal portion, is situated the decussation
of the brachium conjunctivum. In order to study the relations of
the brachium conjunctivum to the red nucleus, it will be necessary
to recall the various decussations of the tegmeiitum. In the description of the brachium conjunctivum, note was made of three
decussations : (1) a commissure between Bechterew's nuclei, (2) the
dorsal bundle of the brachium conjunctivum and (3) the ventral or
main part of the brachium conjunctivum (Plate vin).
In regard to the relations of the brachium conjunctivum to the
nucleus ruber, the model makes three points clear: first, that some
of the fibres of the brachium conjunctivum pass into the dorsal
capsule of the nucleus ; second, that some of the fibres pass through
the nucleus ; and third, that others end in the nucleus. The fibres
entering the dorsal capsule are distinctly visible on the left side
of Plate vin, where they appear to spread out over the nucleus.
The relation is evident in section (Fig. 16) which is taken just
dorsal to the level of the nucleus ruber. The fibres that pass
through the nucleus appear as a bundle cut in cross-section at the
lateral, proximal angle of the dorsal capsule (Plate vin, left side).
In regard to this bundle, a comparison of the two sides of the model
will show three points: (1) that the bundle passes obliquely through
the dorsal portion of the nucleus and leaves its dorsolateral portion ;
(2) that it enters the lateral region of the capsule, which is Forel's x
Feld BATh; (3) that it comes to lie immediately adjacent to the
lemniscus medialis. The fibres that end in the red nucleus enter
the dorsomedian portion and the space has been left vacant in
1 Forel says that BATh. consists mainly of an upward continuation of
the brachium conjunctivum. Forel, op. cit., S. 426.
Plate vin to show their position. A single section will make these
relations plain (Fig. 19). In passing ventralward through the
nucleus, the fibres become much fewer and more scattered (Figs.
20 to 23). In fact, there are no medullated fibres in the ventral
portion.
Capsule of the The capsule of the nucleus ruber is peculiar in being a complex
* of cells as well as fibres. The dorsal capsule is almost wholly made
up of fibres; in the proximal capsule, however, cells predominate,
while the ventral capsule at this stage of development is made up
of cells with no medullated fibres.
The spinal surface of the nucleus is related to three groups of
fibres; first, to the brachium conjunctivum ; second, to the fibres of
the jSL oculomotorius, and third, to a few fibres that enter the midbrain from the lemniscus medialis (Plate iv).
The medial wall of the capsule is incomplete and consists of a
few fine fibres adjacent to the dorsal capsule. Besides these, the
fasciculus retroflexus of Meynert bounds a part of this surface
(Plate vn). The dorsal capsule consists mainly, as has been said,
of fibres from the brachium conjunctivum (Plates iv and vm). It
covers the dorsal surface of the nucleus, and its lateral border lies
adjacent to the medial lemniscus. Dorsal to this capsule is the
formatio reticularis region of the midbrain, and medial to it is the
fasciculus longitudinalis medialis. According to Forel, 1 the capsule receives fibres from each of these structures.
The dorsal capsule passes immediately into the superior capsule.
Plate vm shows well the superior capsule with its relations to the
fasciculus longitudinalis medialis, the fasciculus retroflexus Meynerti and the lemniscus medialis.
The area adjacent to the lemniscus medialis, including a portion
of the dorsal and superior walls of the capsule, corresponds to
Forel's 2 Feld BATh.
1 Forel, op. cit., S. 424.
2 Forel describes the area BATh as being dorsolateral to the nucleus
ruber. Op. cit., S. 415.
The proximal capsule of the model will serve to illustrate in part
ForeFs description of the area between the nucleus ruber and the
thalamus, though the model includes but the lower border of the
region. The dorsal part of the proximal capsule is rich in fibres, which it receives from the dorsal capsule. The middle part consists of mixed fibres and cells, while the ventral part has more
cells than fibres; indeed, toward the lateral border there is a fairly
definite nucleus. 1
In the centre of the dorsal edge of the proximal capsule the fasciculus retroflexus of Meynert plunges through the capsule and into
the nucleus ruber (Plates iv and vm). The capsule is thickest at
its lateral border. The relation of the fasciculus longitudinalis
medialis to the capsule is an interesting one. In Plate vm will be
seen the trough of the fasciculus longitudinalis medialis ' and the
groove for the nucleus of Darkschewitsch. This groove opens out
onto the surface of the superior capsule. "While the main bulk of
the fibres of the fasciculus longitudinalis medialis do not pass beyond the nucleus, yet a small bundle of fine fibres passes onward
into the medial border of the superior capsule and is gradually lost
among its cells and fibres. This relation has been demonstrated
already by Forel. 2
Reference has already been made to the lateral capsule as a
part of the midbrain sheet. The lemniscus medialis itself forms
a part of the lateral wall of the nucleus. The part of the capsule
adjacent to the lemniscus medialis is by far its densest portion and
its fibres enter Forel's B Feld BATh, and Flechsig's Haubenstralilung. The fibres of the ventral part are few and scattered.
The origin of the fibres of the lateral capsule deserves consideration. (1) The lemniscus medialis, as has been said, forms a part
of the capsule; (2) fibres of the medial and ventral portion of the
pontal sheet enter the midbrain and spread out over the lateral surface of the nucleus. In the sections it is hard to separate these
fibres from those of the brachium conjunctivum (Fig. 20).
(3) Fibres of the brachium conjunctivum appear in some sections
to enter the lateral capsule. (4) In Plate v of the model can be
seen a small nucleus lying in a lateral capsule and in the corresponding sections, certain fibres appear to be definitely related to
this nucleus (Fig. 21). According to Fore], the capsule receives
fibres from the nucleus ruber.
1 This agrees exactly with Forel, who has divided the area into three
zones: a dorsal or Forel's Feld H, a middle or the zona incerta, and a
ventral, or Liiy's body. Forel, op. cit., S. 415.
2 Forel, op. cit., S. 420.
3 Forel, op. cit., S. 425; v. Monakow, op. cit., S. 28. 7
The description of the lateral capsule as given in For el's article
appears to me to apply more to its dorsal portion. Their origin is
hard to trace. In passing farther ventralward (Fig. 20), there is a
great thinning out of the capsular fibres. In the first place, the
lateral wall has become reduced to a few scattered fibres. By
following carefully between the last two sections, it seems clear
that some of the fibres of the lateral wall come from the pontal
sheet and the brachium conjunctivum. At the level of Fig. 21,
however, its fibres appear to be directly related to a small mass of
cells lying distal to the nucleus ruber and surrounded by the fibres
of the root of the 1ST. oculomotorius (K\i. x. of 1. c. of N"u. r.,
Plate iv). Forel's Feld H shows clearly in Fig. 21. The fasciculus retroflexus on the medial border will be described later. In
passing through Figs. 22 and 23, it is evident that the fibres around
the nucleus are becoming fewer, while the cells become more and
more numerous, especially in the proximal and adjacent lateral
capsules. In Fig. 24 are the cell masses that underlie both the
nucleus ruber and the substantia nigra.
The longitudinal series is better than the transverse for obtaining
a clear idea of the relations described above. Starting from, the dorsal
aspect, in Fig. 13, is seen the area of the formatio reticularis which
lies dorsal to the nucleus ruber; from this, one passes into the area of
the definite dorsal capsule in Fig. 16. The relation of the fasciculus
longitudinalis medialis to the nucleus of Darkschewitsch and the
superior capsule of the nucleus ruber may be followed at the same time
as far as Fig. 21. In Fig. 19 are seen, (1) the lemniscus medialis as a
part of the lateral capsule; (2) the brachium conjunctivum just distal
to the nucleus; (3) the relations of the N. oculomotorius; (4) Feld BATh
of Forel; and (5) the fibres of the fasciculus longitudinalis medialis
passing into the nucleus of Darkschewitsch (Nu. f. 1. m.). In this section it will be noted that there are a few fibres making a medial capsule.
3. FASCICULUS EETROFLEXUS OF MEYKEKT.
Fasciculus The f asciculus retroflexus of Meynert is easy to follow in sections
t 8 (Fig. 19). Its position and relation to the nucleus ruber are clear
in the illustrations (Plates iv, vn and vm). Its nucleus of origin
is outside of the limits of the model. The bundle enters on the
proximal aspect of the model as a band 1 mm. wide, and passes
obliquely medialward and ventralward, and plunges through the
nucleus ruber and its capsule. It both enters and leaves the
medial surface of the nucleus entering near the proximal border just dorsal to the middle of the nucleus and leaving near the distal
border at about the middle of the dorsoventral diameter. On
emerging from the nucleus the bundle immediately spreads out
into a sheet more than twice as broad as the entering bundle (Plate
vn). The fibres end in the borders of the fossa interpedunculare
just distal to the nucleus ruber. Between the fibres are to be seen
a few scattered cells, the remains of the ganglion interpedunculare.
The root-fibres of the !N". oculomotorius pass through the area of
the bundle as it emerges from the nucleus ruber.
In longitudinal sections the bundle is easily traced. In Fig. 16 are
seen a few fibres just entering* the edge of the section. It will be noted
that only the peripheral fibres of the bundle are medullated. Figs. 19
and 20 carry the bundle to the edge of the nucleus ruber, while Figs. 21
and 22 take it through the nucleus. The last trace of the bundle is seen
in Fig. 23, and here the cells of the ganglion are especially clear. The
transverse series does not go entirely through the nucleus ruber, so the
entrance of the bundle can not be seen; however, Fig. 50 shows its fibres
near the region of the ganglion interpedunculare.
4. DECUSSATIO TEGMENTI DORSALIS MEYNEKTI.
The decussatio tegmenti dorsalis Meynerti shows in Plate vm Dorsal tegmentai
(Fig. 47). It lies proximal to the ventral part of the brachium
conjunctivum. The course of the fibres to the decussatio is indicated in Plate iv. If the bundle in Plate iv be imagined as continued to the level of the radix descendens (m.) 1ST. trigemini, the
tract can be well traced. The fibres are difficult to follow in the
longitudinal series in this part of their course, but easy to trace in
transverse sections. The bundle then starts just lateral to the radix
descendens (m.) E". trigemini, 1 and curves across the midbrain
between the brachium conjunctivum and the stratum album profundum.
1 Meynert believed that the bundle has a definite relation to this nerve.
Cf. Forel, op. cit., S. 442.
The decussation is just ventral to the fasciculus longitudinalis medialis. In Plate vm it can be made out that the
decussation curves so that the fibres on leaving it turn toward the
spinal cord. In the longitudinal sections these fibres can be seen
to pass through the brachium conjunctivum and to enter the longitudinal bundles of the formatio reticularis alba of the pars dorsalis
pontis. These fibres have not been differentiated in the model from the other longitudinal bundles of the middle region of the
tegmentum. 1
In tracing the fibres of this bundle in the longitudinal series, it
will be easiest to begin with the decussation (Fig 1 . 19). By passing
dorsalward, one can trace at the same time the fibres coming- to the
decussation from the level of the radix descendens (m.) N. trigemini,
and the fibres leaving the decussation to form a longitudinal path in
the pons. In Figs. 16 and 18 are seen the fibres turning toward the
pons. The bundles passing to the decussation do not come out in these
drawings, since the fibres are delicate and are mixed with the bundles
of the root of the N. oculomotorius. In Fig. 13 (D. t.), however, these
fine fibres are plain.
In the transverse series the decussation is seen just ventral to the
nucleus of the N. oculomotorius (Fig. 48), while the fibres passing to it
are plain on Fig. 47. In this section the fibres show a broad curve and
there is a space between them and the stratum profunduin album.
5. DECUSSATIO TEGMENTI VENTBALIS or FOEEL.
ventral tegmentai The decussatio tegmenti ventralis of Forel is represented at this
VonL stage by a few delicate fibres ventral to the decussatio tegmenti
dorsalis Meynerti. They show in Plate vm, and in Fig. 48 and
in Fig. 20 (D. t).
6. STBATUM ALBUM PBOFTJNDTJM.
Deep white layer The stratum album profundum of the superior colliculus is conn ' spicuous in the model of the midbrain (Plates in, iv, v and vm).
The deep white fibre layer is, in reality, a composite of fibre
systems, but its shape as a whole will be considered first. It is a
hollow shell that outlines the central gray matter of the midbrain
(Plate m). Through the centre of the cavity of the shell passes
the central canal describing the midbrain curve; the sides of the
shell rest upon the fasciculus longitudinalis medialis as a base
(Plate iv). As seen in Plate m, the shell is open on its distal and
dorsal aspects, while at the proximal end it is completed across the
midline by an arch. The arch is placed vertically (Plate vm).
The side view is of value in studying its relations (Plate iv). This
view shows the curve of the fasciculus longitudinalis medialis
through which passes the radix N. oculomotorii. Dorsal to the
1 The fibres from Meynert's decussation have been called the descending bundle of the tegmentum, and are pictured by Eamon y Cajal.
Ramon y Cajal, op. cit., S. 114.
fasciculus longitudinalis medialis stretches the lateral wall of the
deep white shell. In this wall is an oval space, the distal end of
which is just dorsal to the opening for the root of the oculomotor
nerve. The wall is divided into two parts by a curved ridge that
runs in a dorsoventral direction. This ridge lies at the junction
of the middle and proximal thirds of the wall and extends dorsalward from the proximal end of the space just mentioned. Distal
to the ridge is a depression, which is due simply to the prominence
of the ridge. This ridge appears to mark a difference in structure
between the two parts, for distal to it the wall consists of a thin
flat sheet in which the fibres run longitudinally, while proximal
to it is the arch of the shell in which the fibres curve across the midline. This arch, in contrast to the thin sheet below the ridge, is
thick and densely packed, at least in its ventral portion. The
details of the direction of the fibres are to be considered later.
The distal margin of the flat sheet is marked on the external surface
by a dorsoventral groove, below which pass the fibres of the radix
descendens (m.) !N". trigemini. This root of the trigeminal nerve
passes spinalward in about the same plane as that occupied by the
deep white sheet.
The internal wall of the shell is practically the converse of the
external (Plate m), for opposite the external ridge is a concavity,
while just distal to it is an internal ridge. Passing spinalward
from this internal ridge is the flat sheet, which runs down to a
second ridge on the internal surface. This ridge lies in the lower
part of the midbrain and practically limits the deep white layer.
Distal to it runs the radix descendens 1ST. trigemini. The exact
point at which the deep white ends and the root of the ~N. trigeminus begins has never been determined, but the model at least
suggests that this ridge is the junction of two different fibre systems. The arch or commissure is to be seen in Figs. 5 and 12.
In the latter the inner wall of the base of the arch comes into sight.
Just at the junction of the pillars of the commissure with the fasciculus longitudinalis medialis and the proximal capsule of the
nucleus ruber is the groove for the nucleus of Darkschewitsch.
This groove has already been noted as opening out upon the superior capsule. The relative thickness of parts of the arch varies
markedly. The ventral part contains most of the fibres. Dorsal
to it is an area which shows no medullated fibres at all. The sections in this area, however, are decolorized more than the rest of
the series. Just dorsal to this space is a narrow band of a few, fine,
decussating fibres.
Deep white layer These form relations, namely, the external and internal ridges and the
in sections. i ower limiting ridge, together with the arch over the canal, will make
clear the direction of the fibres, as seen in sections. For example, between the proximal, internal ridge and the lower limiting ridge, the
fibres run in a longitudinal direction and form a definitely circumscribed, though narrow bundle (Figs. 5 and 6). At the limiting groove
these fibres appear to break, and distal to the groove is situated the
radix descendens (m) N. trigemini. This can be traced in Fig. 5 directly
to the level of the main root of the N. trigeminus, a point which is seen
clearly in the model (Plate v). In section (Fig. 6) the descending root
of the nerve is more broken, inasmuch as this is the level of its nucleus,
of origin, which is situated in the locus cseruleus.
To return to the midbrain shell, the same two sections (Figs. 5 and 6)
will show that the external ridge is made up of fibres running in a
wholly different direction. Indeed, they slant into the deep white from
the formatio reticularis, so that while the internal border of the deep
white is definite, the external border is extremely indefinite. These
fibres from (or to) the formatio reticularis slant into the ridge and
decussate in the commissure.
Passing Tentralwa'rd we come to a level in which no decussating fibres
can be seen, but the external ridge continues to have the same structure (Fig. 9). The next few sections, however, enter into the area of
the decussation and the pillars of the arch (Figs. 11, 12 and 13). The
section in Fig. 16 passes through the nucleus of Darkschewitsch at
the base of the pillars of the arch. In the transverse series the stratum
album profundum can be traced through Figs. 43 to 51. Certain points
are brought out more clearly here than in the longitudinal series: (I)
the fibres that slant into the ridge (Figs. 47 and 48), (2) the posterior
commissure and its relation to the nucleus of Darkschewitsch (Figs.
50 and 51) (Nu. c. p.).
In regard to the course of these fibres the model confirms the
findings of Held rather than those of Ramon y Cajal, the former
stating that the fibres slant into the posterior commissure from the
superior colliculus. These fibres decussate in the arch and pass
down in the pillars to the nucleus of Darkschewitsch.
The fibre relations of the deep white layer have now been completed, except the fact that the space left in the lateral wall really
contains fibres (Plate iv). A single section will show, however,
why this space was left in the model (Fig. 12). The contrast between this section and Fig. 6 is marked, for instead of having the
narrow band between the medial ridge and the N. trigeminus, as
in Fig. 6, the corresponding area in Fig. 12 is evidently a place where fibres of the fonnatio reticularis alba end (or begin) in the
central gray matter of the midbrain. This stratum profundum
album forms the boundary of the central gray matter, and the
area just described shows that at least some of its fibres are connected with the cells within. The contents of the midbrain shell
are: (1) the nuclei of the oculomotor and trochlear nerves and the
roots of these nerves, (2) the central gray matter, and (3) the central
canal.
7. SUBSTANTIA CENTRALIS GRISEA.
The shape of the central gray matter, substantia centralis grisea, central gray
is worthy of mention. Its outline is given in the model only in the m
region of the midbrain, where the stratum album profundum
forms a definite border for it (Fig. 6). In the medulla oblongata,
however, it can be readily constructed from the shape of the floor
of the fourth ventricle. Certain structures in the central gray
matter have already been considered, namely, the various nuclei of
the cerebral nerves. These can be divided into two groups, first,
the median motor groups of nuclei, that is, of the Nn. hypoglossi,
abducentes, trochleares et oculomotorii, which lie embedded in the
fasciculus longitudinalis medialis on the border of the central gray
matter (Figs. 6 and 12); second, certain of the sensory nuclei,
namely, the superior and medial, vestibular nuclei, the nucleus
tractus solitarii and the nucleus alse cinerese (Figs. 6 and 7).
Besides these nuclei connected with the cerebral nerves, there is
a definite and clearly defined nucleus in the pons region. It corresponds to the descriptions of the substantia ferruginea and lies
opposite the decussation of the brachium conjunctivum (Plate m,
Fig. 7). In both series, and in the model as well, this nucleus
is situated in the central gray matter, exactly dorsal to the fasciculus longitudinalis medialis, whereas, in ForeFs picture, it is
placed slightly dorsolateral (Figs. 7 and 41).
The central gray matter of the midbrain is better developed than
that elsewhere. Its shape is outlined by the stratum album profundum and the fasciculus longitudinalis medialis; it contains the
nuclei of the oculomotor and trochlear nerves, as well as the nucleus
of Darkschewitsch. It has been mentioned that certain of the
fibres of the formatio reticularis appear to be connected with it.
To complete the description of the area of the midbrain medial to the midbrain fibre-sheet, there is left the large area which lies
between the stratum album profundum and the lemniscus superior
and dorsal to the nucleus ruber (Plate vm). This area contains,
first, the nucleus colliculi inferioris, which has already been described, and second, the formatio reticularis of the inferior and
superior colliculi. The formatio reticularis of the entire model,
however, is to be considered later.
These structures, lateral from the midbrain sheet, are the substantia nigra (together with a small nucleus possibly derived from
it) and the pyramidal tract.
8. THE PYRAMIDAL TRACT.
The pyramidal The pyramidal tract is non-medullated at birth, but its position
' can be related as follows: In Plate n it lies just external to the
substantia nigra. (This is best seen in Quain's Anatomy, op. cit.,
Vol. in, Pt. i, page 42, Fig. 33; also see other text-books). It
plunges through the pons (Fig. 22) and lies on the ventral surface
of the medulla oblongata. Its decussation at the junction of the
cord and medulla is on Fig. 21.
9. SUBSTANTIA NIGRA.
substantia nigra. The substantia nigra lies in the ventral part of the midbrain
(Plate n). It is larger than the nucleus ruber. It is oblong in
shape and is placed against the lateral surface of the lemniscus
medialis and lateral capsule of the nucleus ruber. It lies at an
angle to the long axis of the model, so that its proximal edge is
farther from the midline than the distal. Just lateral to it is the
area in which the pyramidal tract develops at a later stage, and
though the model does not show the tract, it can readily be imagined
plunging into the pons in this region.
The shape of the nucleus is fairly regular. The ventral border
a straight line in the model rests upon the cellular area which
the substantia nigra and the nucleus ruber have in common. The
nucleus ruber can be easily outlined from this cell-mass by its
color, but it is practically impossible to make a definite ventral limit
in these sections for the substantia nigra. The dorsal border of the
substantia nigra is curved, and, at the distal dorsal angle, the
nucleus is notched to receive a bundle of fibres from the lemniscus
medialis (Plate n). This bundle is shown in Plate v.
The substantia nigra is familiar in the sections ; it is to be seen in all Substantia nigrs
the cross-sections of the midbrain and in all the longitudinal sections in sections.
of the ventral part of the same. Its relations to the lemniscus medialis
and the nucleus ruber are brought out well in both series (Figs. 19 to
24). The first two sections of the series show the bundle of fibres of
the lemniscus medialis, that enters the substantia nigra. The last section shows the cell-area common to the two large nuclei of the midbrain. (Lectus substantia nigrse et nuclei rubri.) The absence of fibres
except the small bundle from the lemniscus medialis is to be noted in
the sections. The transverse series (Fig. 49) may be taken as a type of
the nucleus. The angle, at which this section is cut, readily explains
itself on the model. A cross-section taken at the extreme spinal end
of the nucleus shows the bundle entering from the lemniscus medialis
(Fig. 46). The connection appears to be much more intimate from this
aspect than the longitudinal series showed.
==Chapter IX. Formation Reticulaeis Alba et Geisea==
Formatio Though the formatio reticularis is represented in the model for
a ' the most part merely by a space, nevertheless certain of its relations
can be made quite clear. In considering the three regions of the
model, each is characterized, first, by a special form of the sensory
or central fibre-mass, and second, by nuclei limited to the region.
For example, the medulla oblongata has the vertical medial sheet
and the olive; the pons has the horizontal sheet and the pontal
nuclei, while the midbrain has the oblique-lateral sheet and the
nucleus ruber and substantia nigra, which have, as has been said,
a common bed of cells.
The position of the formatio reticularis has a definite relation to
these main structures. It lies dorsal to the large nucleus of the
region in every case. In the medulla oblongata it lies dorsal to
the inferior olive and lateral to the vertical sheet; in the pons, it
lies dorsal both to the pontal nuclei and to the pontal sheet, that is,
the sheet forms a boundary between the pontal nuclei and the
formatio reticularis. In the midbrain, the formatio reticularis lies
dorsal to the nucleus ruber and the substantia nigra, but here the
fibre-sheet is reversed in position as compared with the medulla
oblongata, for it lies lateral rather than medial.
The reticular area of the medulla oblongata is best seen from
the side (Plate v); the pontal and midbrain reticular areas from
the dorsal aspect in Plate vn, and the midbrain area in Plate vm.
The intrinsic structures of the formatio reticularis are its long
and short fibre-tracts and its cells, both the diffuse areas and the
more or less definite nuclei.
The longitudinal section in Fig. 9 gives a comprehensive view
of the entire formatio reticularis. It is bounded medially by the
fasciculus longitudinalis medialis and the stratum profundum
album; laterally by the nucleus funiculi gracilis and the nucleus
funiculi cuneati, the corpus restiforme, the sensory cerebral nuclei and the lemniscus lateralis. In this section several points are to be
noted: (1) the large number of longitudinal fibres, some of which
seem to run the entire length of the formatio reticularis; (2) the
comparatively even distribution of these fibres; (3) the large number of cells, and (4) the absence at this level of special groups or
nuclei, for the whole area seems to be one continuous nucleus.
This section may be taken as a type of the dorsal area of the formatio reticularis.
This level of the formatio reticularis is in contrast to a level
farther ventral (Fig. 13). Here we have the longitudinal fibres
and the cells again ; but the fibres run in fairly definite bundles and
the cells form fairly definite nuclei. The first level was undifferentiated and showed fibres extending through the whole length of
the medulla oblongata, pons and midbrain, while this level is distinctly differentiated and shows shorter tracts breaking up into
nuclei. For example, distal to the radix 1ST. abducentis is the
middle part of the medulla sheet, namely, its formatio reticularis
Bundle; and proximal to the root of the E". abducens the fibrebundle turns lateral ward and splits into two parts, a medial and a
lateral.
These two longitudinal fibre-bundles can be traced from the
region just proximal to the E". abducens through the pons and into
the midbrain; the fibres pass directly through the brachium conjunctivum. The more centrally placed of these longitudinal fibres
run to the border of the central gray masses and there end abruptly,
while the more lateral fibres end indefinitely in a great cell area
in the midbrain, namely, the nucleus lateralis superior of Flechsig.
The fibres from the decussatio tegmenti dorsalis of Meynert turn
spinalward and pass through the formatio reticularis of the pons.
They cannot be separated as a distinct bundle.
The formatio reticularis area of the entire section is one large
nucleus; nevertheless five fairly distinct groups of cells can be
differentiated within it. The first of these is the nucleus centralis
inferior, which lies in the medulla sheet distal to the radix N". abducentis (Plate vi, Fig. 35). The second, the nucleus reticularis tegmenti, lies between the formatio reticularis fibres just proximal to
the E". abducens (Plate vm, Fig. 40). The third, the nucleus
centralis superior medialis, lies between the two medial fibrebundles in the proximal part of the pons (Plate vm, Fig. 42). In Plate vin the curve of the formatio reticularis bundle corresponds
to this nucleus. The fourth nucleus is the nucleus centralis superior
lateralis, which lies at the same level as the third but farther lateral.
It occupies the hollow of the brachium conjunctivum (Plate vm,
Fig. 42). The fifth is the nucleus lateralis superior, or formatio
reticularis grisea of the midbrain (Plate vm).
As has been said, besides these fibre-bundles and nuclei, the section in Fig. 13 shows a diffuse formatio reticularis area extending
throughout the section and lying lateral from the tracts just considered. This lateral area is in contrast to the lateral area of the
more dorsal level. The longitudinal fibres are almost entirely
wanting, their place being taken by transverse fibres or internal
arcuates. These fibres are so delicate that they show better in
transverse section (cf. Fig. 30). Beside the definite arcuate bunbles from the dorsal funiculi of the cord and the decussating fibres
of the brachium conjunctivum, the entire area from the proximal
limit of the fasciculus cuneatus to the level of the motor root of
the ~N. trigeminus shows numbers of delicate arcuate fibres cut in
cross-section. This area corresponds in extent to that of the tractus
spinalis IN", trigemini, and doubtless many of these fibres come from
its nucleus.
It will make the formatio reticularis more interesting to compare with two sections, one taken dorsal to the level of the formatio reticularis and the other ventral. In the first place Fig. 6
lies dorsal to the formatio reticularis. This might be called the
level of the dorsal cerebral nuclei or the level of the central gray
matter and its differentiated nuclei. The longitudinal fibres of
the formatio reticularis have disappeared, and the following nuclei
of the cerebral nerves are visible, the !N". glossopharyngeus, 1ST.
vagus, E". acusticus, "N. facialis and "N. trigeminus. Moreover, the
central area of the section is a mass of cells around the central canal.
The ventral level, on the other hand, as seen in Fig. 20, is the level
of the main regional nuclei, the olive, the pontal nuclei, the substantia nigra and nucleus ruber. At this level there are no nuclei
of cerebral nerves nor fibres of the formatio reticularis. It is,
in fact, a non-medullated area in which the motor fibres, that are
soon to characterize this level (i. e., pyramidal tract), can just be
seen, as lines of brown stain on the sections.
In the reticular area of the medulla are two longitudinal tracts,
first, the descending bundle from Deiters' nucleus to the spinal
cord (Plate v), and second, the tract described as extending from
Burdach's nucleus up to the region of the nucleus ambiguus
(Plate vii, Fig. 12) (Tr. fr. Nu. D. and F. c. to F. r.).
It will be noted in both of the sections (Figs. 9 and 13) that the
formatio reticularis region does not reach either the proximal or the
distal limit of the section; that is to say, the formatio reticularis
of the model region is not connected with the cord, nor yet with
the hypothalamic region at so dorsal a level. This is due to the
cervical and the midbrain curves. The model shows this point
well. A cross-section of the spinal cord, showing its reticular area
is to be seen in Plate v. The fibres of this area must curve over
the dorsal surface of the olive to enter the formatio reticularis area
of the medulla oblongata. On the other hand, the proximal connection shows best in Plate vm, where the transition is made just
over the dorsal capsule of the nucleus ruber. It is not necessary to
say that it is impossible to limit exactly the dorsal capsule from the
formatio reticularis; indeed, Forel says that the formatio reticularis enters into the formation of the capsule of the nucleus ruber.
Fig. 16 shows these relations clearly, for at either end of the section
is to be seen an area of formatio reticularis.
Beside the large diffuse cell-masses of the formatio reticularis
and the more definite cell-groups connected with the longitudinal
tracts, there are scattered in the formatio reticularis certain definite
little masses of cells. They are situated on either side of the
brachium conjuiictivum sheet in its ventral course from the cerebellum to the decussation (Plates in and iv).
CONCLUSION.
GENERAL SUMMARY.
It will now be possible, I think, to reduce the model to simple summary of
terms, even though it may seem to be complex. As viewed from
the side, the model consists, in general, of two levels a ventral J
and a dorsal. The ventral level is characterized, first, by a remarkable absence of medullated fibres at this stage of development, and
second, by the presence of large definite nuclei. These nuclei
characterize the regions they occupy; the olive of the medulla,
Comparison the pontal nuclei, the nucleus ruber and substantia nigra in the
withcSS! midbrain. This is the level and these the structures by which the
medulla oblongata, pons and midbrain differ from the cord. The
absence of medullated fibres speaks for the later development of
these structures. This level is eventually occupied by the
brachium pontis and the pyramidal tract, the fibres of which have
long been laid down at this period. 1
The pyramidal tract, which develops in this level, lies wholly on
the surface of this region, save where it plunges through the pontal
nuclei. It lies far from the dorsal area, which represents the more
developed part of the model and has no form relation to it save
that the decussation makes a slight impression on the trough for
the ventral horn; that is to say, the pyramidal tract has no influence in moulding the shape of other structures; it rather adjusts
itself to structures already formed. In this it is in contrast to the
sensory tract, which is so closely related in form to adjacent structures. This illustrates well the point which His has made, that
the difference in time development determines the relative positions of structure. 2
Continuation The dorsal half of the model, on the other hand, corresponds
structures, rather to the spinal cord. The easy transition of the cord into the
dorsal part of the model is clear in the view of the lateral surface
of the model. This level, with all its complexity, is in reality
simple. It consists (1) of long tracts on the way to the cortex,
(2) of long tracts to the cerebellum, namely, the brachium conjunctivum and corpus restiforme; (3) of the cerebral nuclei, their
root-bundles and paths; (4) the association areas or formatio reticularis alba and grisea.
The central fibre mass is a structural unit in the form of three
sheets, the medulla, pontal and midbrain, which contain the medial
and lateral lemniscus, or the main sensory path toward the cortex.
It contains also certain shorter tracts, the fasciculus longitudinalis
medialis, the lemniscus superior and unnamed formatio reticularis
fibres. Of the tracts to the cerebellum, the corpus restiforme lies on the lateral surface of the medulla oblongata, while the brachium
conjunctivum, being related to the nucleus ruber, lies within the
pons and midbrain.
1 Flechsig. Die Leitungsbahnen im Geblrn und Kiickenmark des Menschen, Leipzig, 1876, S. 192.
2 Die Neuroblasten und deren Entstehung im embryonalen Mark,
Abhandl. d. math.-phys. Cl. d. k. sachs. Gesellsch. d. Wissensch., Bd. xv,
Leipzig, 1889, S. 292.
SUMMARY: GROUPING OF CEREBRAL NERVES, ETC. Ill
The cerebral nerves are divided into two groups, a medial and a Grouping of
lateral. The motor nuclei are definite, compact masses, with the C(
exception of the nucleus ~N. accessorii, which represents the transition from the type of the nuclei to the spinal cord. The motor
nuclei correspond to the ventral-horn cells. They are related to
f ormatio reticularis areas ; the median group to the fasciculus longitudinalis medialis, the lateral to the formatio reticularis alba. The
root-fibres of the lateral group, with one exception, take an indirect
course to the surface, showing that they have developed in an area
of complex growth. The sensory nuclei all belong to the lateral
group. They correspond, in the main, to the dorsal horn of the
spinal cord, and thus occupy a dorsal level. They are diffuse and
cover a wide area. All but two of them, namely, the nuclei of the
!N". trigeminus and !N". cochleae, lie in the substantia centralis grisea.
With the exception of the nuclei N. cochleae, they border the
formatio reticularis. In general, they are characterized by long
descending tracts accompanied by nuclei. The nerves of the special
senses do not conform wholly to the general type, for the !N".
vestibuli is peculiar in its relations to the cerebellum, and the "N.
cochleae in its well-developed and complex central path.
The formatio reticularis consists of mixed cells and fibres. The Formatio
dorsal level represents the longer association paths of the model, rt
and its cells are diffuse. In the ventral level the fibres are grouped
into shorter paths and then the cells form nuclei in connection with
these short bundles.
The model brings out the fact that the region is divided into
four levels, as has been shown by His from a study of earlier
embryos. I wish to emphasize the large number of nerves represented by nuclei in the first layer, or the substantia centralis
grisea. They are (1) all of the spinal nerves through the nuclei
of the dorsal funiculi, (2) the nuclei of the four motor nerves of
the median group, and (3) all of the sensory cerebral nuclei of the
model except the nucleus of the !N". trigeminus and the N. cochleae.
The second layer, that of the formatio reticularis, includes the
remaining four motor nuclei of the cerebral nerves. That this
position is not primary for these nuclei, but is rather the result of development, is suggested by courses of their fibres. The third
layer includes the olive, pontal nuclei, substantia nigra and red
nucleus, the fourth the pyramidal tract.
The question of the origin of these four layers is one of great
interest. According to His, the motor nuclei, both of the median
and lateral groups, come from the ground plate, while the sensory
nuclei come from the medial part of the wing plates. 1 The third
layer offers an attractive field for study.
Three of its nuclei, namely, the olive, the pontal nuclei and
the red nucleus, are connected with the cerebellum. In the spinal
cord the cells related to the cerebellum are in the nucleus dorsalis
Clarkii which lies between the dorsal and ventral horns. The
origin of the olive, according to His, is from the cells of the
Rautenlippe, which forms the lateral part of the wing plate adjacent to the cells which form the sensory nuclei. This serves to
open up the question of the origin and relations of this ventral
nuclear layer. Have these nuclei a common origin, and what is
the relation of the substantia nigra to the other three?
A part of this question is being studied in this laboratory.
Problems along this line have been opened up by the work of His,
and I can but believe that the application of the wax-plate method
to the study of the development of the central nervous system has
a promising future. With a series of models, the course of development may become a matter of sight and not a theory. Moreover, all those individual differences which may be misleading in
any one model can be easily eliminated when each model is but one
of a series.
1 His, W., Die Entwickehing des menschlichen EautenWms. Abhandl.
d. math.-phys. Cl. d. k. sachs. Gesell. d. Wissensch., Leipz., 1891, S. 1-74.
==Literature==
This list is designed to meet the needs of the student beginning the Study of the Central Nervous System. (It does not represent the full bibliography considered in writing the original article.)
For the development of the Central Nervous System:
His, W. Arch. f. Anat. u. Physiol., Anat. Abth., Leipz., 1893.
For a comprehensive text-book on the Nervous System:
VAN GEHUCHTEN, A. Anatome du Systeme Nerveux De L'Homme. 1897.
For general text-books :
Nervensystem. Prof. Dr. H. Ziehen (Jena), 1899; from Dr. Karl von Bardeleben's Anatomie des Menschen.
OBERSTEINER, H. Anleitung beim Studium der Nervosen Centralorgane. 1896.
QUAIN'S Anatomy. Vol. in, Pt. i. The Spinal Cord and Brain. Edited by Schafer and Thane. 1895. Also Quain's Anatomy. Vol. m, Pt. n. The Peripheral Nerves.
For the development and scope of the Neurone Conception, with a full review of modern investigation and with complete literature :
BARKER, L. F. The Nervous System. 1899.
For a detailed Anatomy of the Cord and Brain :
v. KOELLIKER, A. Handbuch der Gewebelehre, Bd. n.
Leipz., 1896.
For the Anatomy of the Spinal Cord :
VON LENHOSSE'K, M.
For the Tracts as studied by the Method of Successive Myelenization:
FLECHSIG, P. Die Leitungsbahnen im Gehirn und Eiickenmark. Leipzig (1876).
For the Midbrain :
FOREL, A. Arch. f. Psychiat., Berl., Bd. vn (1877), S. 393495.
For a study of the details of the Medulla Oblongata by the Golgi
Method:
RAMO'N Y CAJAL. Beitrag zur Studium der Medulla Oblongata. Deutsche Uebersetz. von Bresler, Leipzig (1896).
For the Acustic Nerve and its central path :
HELD. Arch. f. Anat. u. Phys., Anat. Abth., Leipzig (1891).
For the paths in the cord and brain, especially Medulla and Midbrain :
v. BECHTEREW, W. Die Leitungsbahnen im Gehirn und
TMickenmark. Leipzig (1894).
For Comparative Anatomy:
EDINGER, L. Yorlesungen iiber den Bau der Nervb'sen Cen
tralorgane. Leipzig, 1893.
Journals of Current Contributions:
Le Neuraxe, Van Gehuchten, Lou vain.
Journal of Comparative Neurology, C. J. Herrick, Granville,
Ohio, U. S. A.
Brain, London, England.
Arch, fiir Psychiatric und Nervenkrankheiten, Berlin, Germany.
==Abbreviations==
o, Fibres running from region of lemniscus lateralis toward the dorsal border of brachium conjunctivum.
A. c. (or Aq. c., or Aq. cer.), Aquaeductus cerebri. Silvian.
#, Decussating portion of root of N. trigeminus. N. V.
B. c. (or Br. conj., or Brach. conj.), Brachium conjunctivum. Superior
cerebellar peduncle.
B. c. (d.), Brachium conjunctivum (dorsal bundle).
C. a., Columna anterior (Columna ventralis). Ventral column.
C. c., Canalis centralis.
C. i. (or Coll. inf.), Colliculus inferior. Inferior Corpora Quadrigemina.
C. p., Cornmissura posterior cerebri.
C. r. (or Corp. rest.), Corpus restiforme. Inferior peduncle.
C. s. (or Coll. s., or Coll. sup.), Colliculus superior. Superior Corpora
Quadrigemina.
C. t., Corpus trapezoideum.
D. b. c. (or Dec. B. c., or Dec. Br. Conj.), Decussatio brachii conjunctivi.
Decussation of superior cerebellar peduncle.
D. betw. nu. c. i., Decussation between nuclei colliculi inferioris.
D. c. n. r., Capsula dorsalis of the nucleus ruber. (Red nucleus.)
Dec. Beet., Commissure between Bechterew's nuclei. (Superior vestibular nucleus.)
Dec. 1., Decussatio lemniscorum.
D. p., Decussatio pyramidum.
D. rel. to N. V. (Same as /?.), Decussation related to N. trigeminus.
D. t. v. F., Decussatio tegmenti ventralis, of Forel.
D. t. Vide F. to d. M.
D. t. d. M., Decussatio tegmenti dorsalis Meynerti.
F. a. i., Fibrae areuatse internae.
F. a. i. (d.) (or F. a. i. (Dec. 1.)), Fibrse arcuatae internae (distal
bundle) or Decussatio lemniscorum.
F. a. i. (p.) (or F. a. i. (cun.)), Fibrae arcuatae internae (proximal
bundle).
F. a. i. (vest.) , Fibrae arcuatae internae, pertaining to central vestibular
paths.
F. a. e., Fibrae arcuatae externae.
F. betw. B. c. & h. 1. Vide a.
F. B. c. d. Vide B. c. (d.).
F. c. (or F. cu., or Fa. cun.), Fasciculus cuneatus. Column of Burdach.
F. c. s. (or F. do.), Fasciculus cerebellospinalis. Direct cerebellar
tract.
F. c. to Fr., Fibres from fasciculus cuneatus to forma tio reticularis.
Column of Burdach.
F. fr. d. M., Fibres from Decussatio tegmenti dorsalis Meynerti.
F. fr. f. 1. (1.), Fibres from fasciculus lateralis (lateral group).
Lateral column.
F. fr. f. 1. (m.), Fibres from fasciculus lateralis (medial group).
F. fr. 1. m. to s. n., Fibres from lemniscus medialis to substantia nigra.
F. g. (or Fa. gr.), Fasciculus gracilis. Column of Goll.
F. L, Fossa interpedunculare.
Fib. arc. int. Vide F. a. i. (p.).
F. 1., Fasciculus lateralis.
F. 1. m. (or Fasc. 1. med.), Fasciculus longitudinalis medialis. Posterior longitudinal bundle.
F. 1. p., Fasciculus lateralis proprius. Lateral ground bundle.
F. 1. p. (d.), (or F. 1. p. (4)), Bundle continuous with fasciculus lateralis of the cord.
F. p. (or F. Py.), Fasciculi longitudinales pyramidales. (In Fig. 36
F. p. is Fibrse pontis.) Pyramidal tract.
F. r. a., Formatio reticularis alba.
F. r. M. (or Fasc. retrof.), Fasciculus retroflexus Meynerti.
F. sc. dl., Fasciculus cerebellospinalis dorsolateralis. Direct cerebellar tract.
F. to d. M. (or F. to d. t. d.), Fibres to decussatio tegmenti dorsalis
Meynerti.
F. v. c. (i.), Fibres connecting vestibular area with cerebellum (inner
or medial group).
F. v. c. (o.), Fibres relating the vestibular area with the cerebellum
(outer or lateral bundle).
F. v. 1., Fasciculus ventrolateralis. Ventrolateral column.
F. v. p., Fasciculus ventralis proprius. Ventral ground bundle.
L. c. nu. r., Capsula lateralis nuclei rubri.
L. 1. (or Lemn. lat.), Lemniscus lateralis.
L. m., Lemniscus medialis.
L. nu. r., Lectus nuclei rubri. Bed of red nucleus.
L. s., Lemniscus superior.
Med. obi., Medulla oblongata.
Mesenc., Mesencephalon.
Mot. V. Vide N. V (m.).
N. c. Vide N. VIII (Coch.).
N. 1. 1., Nucleus lemnisci lateralis.
N. Ill, Eadix N. oculomotorii.
N. IV (or N. troch.), Eadix N. trochlearis.
N. V, Eadix N. trigemini.
N. V (dec.). Vide/?.
N. V (m.), or N. Mot. V, Eadix N. trigemini (motor).
N. V (s.) (or N. Sen. V), Eadix N. trigemini (sensory).
N. VI, Eadix N. abducentis.
N. VII, Eadix N. facialis.
N. VII p. p. (or VII (a.)), Eadix N. facialis, pars prima.
N. VII p. s. (or N. VII (c.)), Eadix N. facialis, pars secunda.
N. VII g. (i.) (or N. VII (b.)), Eadix N. facialis genu internuin.
N. VIII (coch.) (or N. c.), Eadix N. cochleae.
N. VIII (vest.) (or N. vest.), Eadix N. vestibuli.
N. IX & X, Eadices N. glossopharyngei et vagi.
N. XI, Eadix N. accessorii.
N. XI p. p., Eadix N. accessorii, pars prima.
N. XI p. s., Eadix N. accessorii, pars secunda.
N. XII, Eadix N. hypoglossi.
Nu. a., Nucleus arcuatus.
Nu. a. c., Nucleus alae cinerese.
Nu. c., Nucleus coluxnnaris.
Nu. c. i., Nucleus colliculi inferioris, Figs. 43 and 44. In Fig. 13, Nu.
e. i. = Nucleus centralis inferior.
Nu. com., Nucleus commissuralis.
Nu. c. p., Nucleus commissurse posterior, or nucleus fasciculi longitudinalis medialis. Posterior longitudinal bundle.
Nu. c. s. (1.), Nucleus centralis superior, pars lateralis.
Nu. c. s. (m.), Nucleus centralis superior, pars medialis.
Nu. d., Nucleus dentatus.
Nu. f. c. (or Nu. f. cu., or Nuc. f. cun.), Nucleus funiculi cuneati.
Nu. f. c. (1.), Nucleus funiculi cuneati lateralis (Blumenau).
Nu. f. g. (or Nucl. f. gr.), Nucleus funiculi gracilis.
Nu. f. 1. m., Nucleus fasciculi longitudinalis medialis or nucleus commissurae posterioris (oberer Oculomotoriuskern or Darkschewitsch) .
Nu. g., Nucleus globosus.
Nu. 1. s., Nucleus lateralis superior of Flechsig.
Nu. N. c. d. (or Nu. N. cochl. cl.), Nucleus N. cochleae dorsalis.
Nu. N. c. v., Nucleus N. cochleae ventralis.
Nu. N. v. 1. (or Nu. N. vest. 1.), Nucleus N. vestibuli lateralis.
Nu. N. v. m. (or Nu. N. vest, m.), Nucleus N. vestibuli medialis
(Schwalbe).
Nu. N. v. s. (or Nu. N. vest, s.), Nucleus N. vestibuli superior (von
Bechterew).
Nu. N. Ill, Nucleus N. oculomotorii.
Nu. N. Ill, 1., (or Nu. N. Ill (a.)), Nucleus N. oculomotorii, pars lateralis.
Nu. N. Ill, m. (or Nu. N. Ill (b.)), Nucleus oculomotorii (medial nucleus).
Nu. N. IV, Nucleus N. trochlearis.
Nu. N. V, Nucleus N. trigemini.
Nu. m. m. N. V, Nuclei motorii minores N. trigemini.
Nu. m. p. N. V, Nucleus motorius princeps N. trigemini.
Nu. N. VI (or Nucl. N. abd.), Nucleus N. abducentis.
Nu. N. VII, Nucleus N. facialis.
Nu. N. XII (or Nucl. N. hyp.), Nucleus N. hypoglossi.
Nu. N. XII, a. K., Nucleus of Holler.
Nu. o. a. d., Nucleus olivaris accessorius dorsalis. Accessory olive.
Nu. of r., Nucleus of the roof.
Nu. o. a. m., Nucleus olivaris accessorius medialis.
Nu. o. i., Nucleus olivaris inferior. Olive.
Nu. o. s., Nucleus olivaris superior. Superior olive.
Nu. o. s. 2, Nucleus olivaris superior, at its junction with the nucleus
lemnisci lateralis.
Nu. r., Nucleus ruber. Eed nucleus.
Nu. r. t., Nucleus reticularis tegmenti.
Nu. t. s. (or Nu. tr. sol.), Nucleus tractus solitarii.
Nu. x. of 1. c. of nu. r., Nucleus capsulse lateralis nuclei rubri.
Nu. y., Anterolateral extremity of nucleus of N. vest, medialis.
P. f., Pedunculus flocculi.
Py., Pyramis. Pyramid.
R. d. N. V, Radix descendens (mesencephalica) N. trigemini.
R. d. N. vest, (or Rad. desc. N. vest.), Radix descendens N. vestibuli.
R. 1., Recessus lateralis ventriculi quarti. Lateral recess of fourth
ventricle.
S. 1., Transverse series.
S. 2., Horizontal series.
S. a., Striae acusticse.
S. a. p. (or St. a. p., or Str. alb. p., or St. alb. p.), Stratum album profundum.
Sen. V. Vide N. V. (s.).
S. f., Substantia ferruginea.
S. g. (or Sub. gel., or Sub. gel. Rolandi), Substantia gelatinosa Rolandi.
S. i. 1. (or St. i. 1.), Stratum interolivare lemnisci. (In Fig. 20 extend
the line through the olive.)
S. n., Substantia nigra.
St. g. c. (or St. gr. c.), Stratum griseum centrale. Central gray
matter.
T. fr. D. to c. (or Tr. fr. nu. D.), Tract from Deiters' nucleus to the
funiculus lateralis to lateral column.
T. s. ( (or Tr. s., or Tr. sol.), Tractus solitarius.
T. s. N. V (or T. s. n. t., or Tr. s. n. t., or Tr. s. N. V), Tractus spinalis
N. trigemini.
V. q., Ventriculus quartus.
==Description of Figures and Plates==
Figs. 3-24. Series of horizontal sections passing through the medulla,
pons and midbrain of a new-born babe. The series is traced from the
dorsal to the ventral surface. The following sections, Figs. 6, 7, 9, 12, 13,
16 and 19 are after Barker, L. F.: The Nervous System and its Constituent Neurones. D. Appleton & Co., 1899. (Preparations by Dr. John
Hewetson.)
Figs. 25-51. Series of transverse sections passing through the medulla, pons and midbrain of a new-born babe. The series is traced from
the spinal cord toward the cerebrum. The following sections, Figs. 25,
28, 31, 33, 35, 36, 39, 41, 42, 46 and 49 are after Barker, L. F.: Op. cit.
(Preparations by Dr. John Hewetson.)
Fig. 52. KEY TO PLANES OF SECTIONS.
PLATE I.
Fig. 1. View of the dorsolateral and lateral surfaces of the nucleus
olivaris inferior.
F. dl. Facies dorsolateralis.
F. 1. Facies lateralis.
F. p. Fissura prima.
F. s. Fissura secunda.
F. t. Fissura tertia.
F. q. Fissura quarta.
L. p. Lobus primus.
L. s. Lobus secundus.
L. t. Lobus tertius.
L. q. Lobus quartus.
Fig. 2. View of the ventral surface of the nucleus olivaris superior.
S. p. Sulcus primus.
S. s. Sulcus secundus.
S. t. Sulcus tertius.
PLATE II.
View of the model from the lateral surface. This view is designed to
relate the model to the cord, the cerebellum and the cerebrum. The
cut edge of the cord shows on the extreme right. The following points
will make the position of the model clear: the dorsal and lateral funiculi
and the dorsal horn of the spinal cord, the cerebellum, the fourth ventricle, the inferior and superior colliculi and the third ventricle.
The color system is as follows: all fibres are in white and black, all
nuclei in colors. Red represents the nuclei of the motor cerebral
nerves, blue the nuclei of the sensory cerebral nerves and yellow all
other nuclei.
Nu. et Radix N. vestibuli: The nucleus is distinguishable from the root
by its color. The ascending and descending parts of the root are to be
determined by their relation to the entering root-bundle of the nerve.
The part of the vestibular nucleus distal to the nucleus N. abducentis is
the nucleus N. vestibuli medialis; the part proximal, is the nucleus N.
vestibuli superior. The nucleus N. vestibuli lateralis (Deiters'), (pars
lateralis) lies in the vestibular tract just dorsal to the corpus restiforme.
9
122 DESCRIPTION OF FIGURES AND PLATES
PLATE III.
View of the model from the dorsal surface. On the right side is
shown the floor of the fourth ventricle; on the left, the structures
beneath are exposed. The position of these structures can be related
to the dorsal funiculi of the spinal cord, the fourth ventricle, and the
inferior and superior colliculi.
Nu. et Radix N. vestibuli: To be distinguished by the colors. The ascending root is marked by the most proximal of the three lines on the
figure; the descending by the most distal line, while the nucleus N.
vestibuli medialis is indicated by the middle of the three lines. The
nucleus N. vestibuli superior is continuous with the medial nucleus and
lies opposite the ascending root. The nucleus 1ST. vestibuli lateralis
consists of two parts, one between the corpus restiforme and the
ascending root, the other in the notch between the medial and superior
nuclei.
Nucleus N. cochlew dor sails: The more proximal of the two lines points
to the striae acusticae.
Traotus solitarius et Nu. alas cinerce: The former is in black and white,
the latter in blue.
PLATE IV.
View of the model from the lateral aspect. After removing from
Plate i, the following structures: the corpus restiforme, the substantia
nigra and the medial, lateral and superior lemnisci. The view is designed to show (1) the sensory nerves and their nuclei, and (2) the midbrain. The nuclei of the dorsal funiculi represent a way-station for the
sensory fibres from the spinal cord; the sensory cerebral nerves are
represented by the nuclei nervi glossopharyngei, vagi, vestibuli et trigemini. These include all of the sensory nerves of the region of the model
except the N. cochleae, which was removed with the corpus restiforme.
Radix N. trigemini (Sens.) : The proximal line runs to the root bundle,
the distal to the tractus spinalis N. trigemini.
Tract from Betters' nucleus to F. i. (3), and Fasciculus lateraMs (4): The
numbers are explained in the text.
PLATE V.
View of the model from the lateral aspect. The sensory nerves of
Plate iv have been removed and all of the motor cerebral nerves except
the N. trochlearis are now shown.
Fasciculus lateralis (2), and Fasciculus lateralis (3): The numbers are
explained in the text.
PLATE VI.
View of the lateral surface of the medulla sheet. The view can be related to Plates n, iv and v, by the position of the nucleus N. abducentis.
Fasciculus ventrolateralis (1): The number is explained in the text.
PLATE VII.
View of the model from a dorsomedian aspect. This view is designed
to show the central fibre mass, that is, the medulla, pontal and midbrain sheets, together with the corpus trapezoideum.
. Fibres running from Lemniscus lateralis to the brachium conjunctivum.
DESCRIPTION OF FIGURES AND PLATES 123
PLATE VIII.
View of the midbrain from the superior or cerebral aspect. This
view can be understood by comparing 1 it with Plates n, iv and v, which
show the stratum profundum album, the lemniscus superior and the
capsula nuclei rubri from the lateral aspect.
7 is a space in the model, in the stratum profundum album where
fibres of the formatio reticularis alba are related to the substantia
centralis grisea.
Fasciculus ventrolateralis (1) : The number is explained in the text.
HORIZONTAL (Frontal) SECTIONS 38, 56 and 62.
(126)
HORIZONTAL (Frontal) SECTIONS 66, 72 and 74.
Q26)
HORIZONTAL (Frontal) SECTIONS 80, 86 and 94.
(127)
HORIZONTAL (Frontal) SECTIONS 100, 108, 114 and 116.
(128)
HORIZONTAL (Frontal) SECTIONS 122 and 126.
(129)
HOKIZONTAL (Frontal) SECTIONS 128 and 136.
J
~
(130)
HORIZONTAL (Frontal) SECTIONS 146 and 162.
(131)
HOEIZONTAL (Frontal) SECTIONS 170, 180 and 202.
be
CROSS-SECTIONS 20-84.
be
CKOSS-SECTIONS 94-146.
f
(134)
CROSS-SECTION 158.
(135)
CEOSS-SECTION 170.
N_^JJ
(136)
CROSS-SECTION 182.
(137)
CROSS-SECTION 190.
p ml
(138)
CKOSS-SECTIONS 200 and 212.
Na.mp.n.T.
B.c.
C.t.
Urn.
Fig-. 38, Series II, Section No. 200.
I(SPflS)
Lm.,
Fig. 39, Series II, Section No. 212.
(139)
CKOSS-SECTIONS 254 and 268.
Fig. 40, Series II, Section No. 254.
Fig-. 41, Series II, Section No. 268.
(140)
CROSS-SECTIONS 290 and 304.
Nu.
St.gr.
Fig-. 42, Series II, Section No. 290.
D.betw.nax.L
NiLcl.
11
Fig. 43, Series II, Section No. 304.
(141)
CROSS-SECTIONS 316 and 330.
S.CL.p,.
NU.C.L
Fig-. 44, Series II, Section No. 316.
a
JS.a.p
A.C-.
N n
Ill .J-V
Fig. 45, Series II, Section No. 330.
(142)
CEOSS-SECT1ONS 338 and 354.
Bec.Br.Con].
J
Fig-. 46, Series II, Section No. 338.
n.m
-S.n.
Fig-. 47, Series II, Section No. 354.
(143)
CKOSS-SECT1ONS 372 and 384.
L.S,
NHL
Fig. 48, Series II, Section No. 372.
Aq.cer.
St. gr. c
Fig. 49, Series II, Section No. 384.
(144)
CROSS-SECTIONS 396 and 420.
Fig-. 50, Series II, Section No. 396.
TtM.
JUL
Fig-. 51, Series II, Section No. 420.
(145)
GUIDE TO SECTIONS IN SERIES 1 and 2.
(146)
INFERIOR OLIVE.
PLATE I.
Lateral Surface.
T.i
Dorsal
Veatrul
FIG. 1.
Ventral Surface.
Lateral
Mesial
FIG. 2.
LATERAL SURFACE a
OF MODEL. |
!~
PLATE II.
s I
26
III
i o
I!
I
6"
11
DORSAL SURFACE OF MODEL.
PLATE III.
Stratum album
profundum
Nucleus N. oculomotor!!
Commissurae nuclei coll;
Fasciculus retroflexus (Meynerti)
Lemniscus medialls...
Nucleus colliculi inferloris . .
Radix N. trochlearls __
A
Brachium conjunctivum
Radix descendens
N. trigemini
Locus caeruleus.
Radix N. trigemini (Mot.)
Radix N. trigemini (Sens.) ,
Nucleus motorius
princeps N. trigemini
Nucleus N. trigemini (Sens.)
Nucleus N.
vestibuli lateralis f|
Corpus restiforme
Nucleus et radix
N. vestibuli
Nucleus N. cochleae dorsalis
Corpus restiforme
Tractus solitarius et
nucleus alae cinereae ""
Nucleus funiculj cuneati .-"''
Fasciculus cuneatus .
Nucleus funiculi gracills ....
Fasciculus gracilis
Nucleus N.
.Substantia fei
.Ventriculus qu
Brachium con;
Corpus restiforme
-Radix N. facial!
--Nucleus N. abd
- fasciculus long
--Nucleus olivaris i
--Nucleus N. hypog
INTERIOR OF MODEL FROM SIDE (one layer removed).
PLATE IV.
<
FURTHER DISSECTION OF INTERIOR OF MODEL FROM SIDES.
PLATE V.
LATERAL VIEW OF MEDULLA SHEET.
PLATE VI.
RELATIONS OF LONG TRACTS.
Capsula
superior
nuclei rubri
PLATE VII.
Radix N. oculomotor! i
Nucleus ruber
Fasciculus retroflexus (Meynerti)
Lemniscus lateralis*
Fasciculus longitudinalis medialis-
Formatio reticularis alba -,Nucleus olivaris superior^
Radix N. facialiSx \
Nucleus N. abducentis -s^.-l
Striae acusticseNucleus N. cochleae dorsalis
Radix N. vestibuli
Corpus trapezoideum'' ,*'*'
Radix N. cochleae- '
Nucleus olivaris inferior -;'''
Nucleus funiculi cuneati
Fasciculus cuneatus to
formatio reticularis
Nucleus funiculi gracilis
Lemniscus
medialis
Corpus
,- 'trapezoideu
^Nucleus oli'
' superior
Stratum interolivare lemnis
--- Nucleus N. hypoglossi
Nucleus olivaris accessorius rr
"Decussatio lemniscorum
Canalis centralis
Substantia gelatinosa (Rolandi)
THE MIDBRAIN FROM ABOVE.
PLATE VIII.
Commissure between Bechterew's nuclei
Corpus trapezoideum and nucleus olivaris superior,
Brachium conjunctivum (dorsal bundle)
Brachium conjunctivum
Decussatio
tegmenti dorsalis .
Capsula dorsalis nuclei rubri
Decussatio tegmenti dorsalis
Decussatio tegmenti ventralis
Nucleus N. abducentis
Fasciculus longitudinalis medialis
Nucleus reticularis Kucleus colliculi inferioris
Capsula nuclei
colliculi inferioris
Position of nucleus
N. trochlearis
Lemniscus superior
V
Position of nucleus
N. oculomotor!!
^Stratum album profundui
7' Lemniscus medialis
Commissura posterior
Fasciculus retroflexus
(Meynerti)


<references/>


==Contents==


tiapsula superior nuclei rubrl
[[Book - An Atlas of the Medulla and Midbrain_1|Chapter I. Introductory]]
:Method Of Using Atlas
[[Book - An Atlas of the Medulla and Midbrain_2|Chapter II. The Long Tracts]]
:A. In The Medulla (Medulla Sheet)
:B. In The Pons And Midbrain (Lemnisci And Formatio Reticularis)
[[Book - An Atlas of the Medulla and Midbrain_3|Chapter III. The Columns Of The Spinal Cord]]
:A. Ventrolateral Column
::(A) Ventral Part
::(B) Dorsal Part
:B. Dorsal Column
[[Book - An Atlas of the Medulla and Midbrain_4|Chapter IV. Cerebellar Peduncles]]
:Inferior Peduncle, Or Corpus Restiforme
:Superior Peduncle, Or Brachium Conjunctivum
[[Book - An Atlas of the Medulla and Midbrain_5|Chapter V. The Cerebral Nerves And Their Nuclei]]
:Median Group (Red In Model).
::(A) N. Hypoglossus, XII Nucleus N., XII
::(B) N. Abducens, VI Nucleus N., VI
::(C) N. Trochlearis, IV Nucleus N., Iv 56
::(D) N. Oculomotorius, III Nucleus N., III
[[Book - An Atlas of the Medulla and Midbrain_6|Chapter VI. The Cerebral Nerves And Their Nuclei (Continued). Lateral Group]]
:A. Motor Nerves (Red In Model)
::(A) N. Accessprius, XI Nucleus N., XI. 
::(B) N. Glossopharyngeus Et N. Vagus, Ix And X Nucleus N., Ix And X
::(C) N. Facialis, VII Nucleus N., VII
::(D) N. Trigeminus, V Nucleus N., V
:B. Sensory Nerves (Blue In Model)
::(A) N. Glossopharyngeus Et N. Vagus, Ix And X Nucleus N. , Ix And X
::(B) N. Trigeminus, V Nucleus N., V
::(C) N. Vestibuli, Viii Nuclei N. Vestibuli
::(D) N. Cochleae, Viii Nuclei N. Cochlese
[[Book - An Atlas of the Medulla and Midbrain_7|Chapter VII. The Inferior And Accessory Olives]]


[[Book - An Atlas of the Medulla and Midbrain_8|Chapter VIII. The Midbrain]]
# Relation Of Its Structures To The Central Fibre Mass
# The Nucleus Ruber (Red Nucleus) And Its Capsule
# The Fasciculus Retroflexus (Meynerti)
# The Decussatio Tegmenti Dorsalis (Meynerti)
#  The Decussatio Tegmenti Ventralis Of Forel
# Stratum Album Prof Undum (Deep White Layer)
# Substantia Centralis Grisea (Central Gray Matter)
# The Pyramidal Tract
# Substantia Nigra


[[Book - An Atlas of the Medulla and Midbrain_1|Chapter IX. The Formatio Reticularis Alba And Grisea]]


/ Nucleus
[[Book - An Atlas of the Medulla and Midbrain - Reconstruction General Summary|General Summary of what Is shown In Reconstruction]]
Fasciculus longitudinalis medialis fasciculi


longitudinalis
[[Book - An Atlas of the Medulla and Midbrain_-_References|References To Literature]]
medialis


[[Book - An Atlas of the Medulla and Midbrain_-_Figures|Figures]]




Lectus nuclei rubri


{{Sabin1901 footer}}
{{Sabin1901 footer}}


[[Category:Florence Sabin]]
[[Category:Florence Sabin]]

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Sabin FR. and Knower H. An atlas of the medulla and midbrain, a laboratory manual (1901) Baltimore: Friedenwald.

Online Editor  
Mark Hill.jpg
This 1901 book by Florence Rena Sabin (1871 - 1953) and her collaborator presents one of the very earliest atlases of the human central nervous system, describing the midbrain and brainstem. This atlas was extremely useful for later researchers attempting to both understand the development and mapping of the midbrain and medulla. Florence Sabin later work was as a key historic researcher in early 1900's establishing our early understanding of both vascular and lymphatic development in the embryo.



Modern Notes: Medulla | Mesencephalon | Florence Sabin

Neural Links: ectoderm | neural | neural crest | ventricular | sensory | Stage 22 | gliogenesis | neural fetal | Medicine Lecture - Neural | Lecture - Ectoderm | Lecture - Neural Crest | Lab - Early Neural | neural abnormalities | folic acid | iodine deficiency | Fetal Alcohol Syndrome | neural postnatal | neural examination | Histology | Historic Neural | Category:Neural


Neural Tube Development
Neural Tube Primary Vesicles Secondary Vesicles Adult Structures
week 3 week 4 week 5 adult
neural plate
neural groove
neural tube

Brain
 prosencephalon (forebrain) telencephalon Rhinencephalon, Amygdala, hippocampus, cerebrum (cortex), hypothalamus‎, pituitary | Basal Ganglia, lateral ventricles
diencephalon epithalamus, thalamus, Subthalamus, pineal, posterior commissure, pretectum, third ventricle
mesencephalon (midbrain) mesencephalon tectum, Cerebral peduncle, cerebral aqueduct, pons
rhombencephalon (hindbrain) metencephalon cerebellum
myelencephalon medulla oblongata, isthmus
spinal cord, pyramidal decussation, central canal
Historic Disclaimer - information about historic embryology pages 
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Pages where the terms "Historic" (textbooks, papers, people, recommendations) appear on this site, and sections within pages where this disclaimer appears, indicate that the content and scientific understanding are specific to the time of publication. This means that while some scientific descriptions are still accurate, the terminology and interpretation of the developmental mechanisms reflect the understanding at the time of original publication and those of the preceding periods, these terms, interpretations and recommendations may not reflect our current scientific understanding.     (More? Embryology History | Historic Embryology Papers)

An Atlas Of The Medulla And Midbrain

Sabin1901 titlepage.jpg
Florence Rena Sabin (1871 - 1953)
Florence Rena Sabin (1871-1953)

By Florence R. Sabin


A Laboratory Manual

Illustrated With Seven Colored Plates, One Black Plate And Fifty-Two Figures


Edited By


Henry McE. Knower, PH.D.

Instructor in Anatomy in the Johns Hopkins University, Baltimore, Md.


Baltimore, Md., U. S. A.

The Friedenwald Company

Publishers

1901


Copyright, 1901, By Florence R. Sabin


The Friedenwald Company Baltimore, Md M U. S. A.

Historic Disclaimer - information about historic embryology pages 
Mark Hill.jpg
Pages where the terms "Historic" (textbooks, papers, people, recommendations) appear on this site, and sections within pages where this disclaimer appears, indicate that the content and scientific understanding are specific to the time of publication. This means that while some scientific descriptions are still accurate, the terminology and interpretation of the developmental mechanisms reflect the understanding at the time of original publication and those of the preceding periods, these terms, interpretations and recommendations may not reflect our current scientific understanding.     (More? Embryology History | Historic Embryology Papers)

Editor's Preface

This Atlas is planned to meet the practical need of some quick and simple, yet full and reliable, means of aiding the student to obtain, from a few sections (or from a series of sections), a reasonably clear idea of the important central relay-station of the brain here presented. (Though representing the human brain, the atlas can be applied to the study of the brains of lower mammals.)


The time allotted to a course in Neurology is generally so short; the sections to be studied exhibit such great special complexity of structure, due to the presence and association of many different centres in the narrow limits of the region; and the descriptions in text-books or lectures are commonly so detailed, or so general or diagrammatic; that many students get but hazy ideas of what is shown in their preparations, without spending more time in the effort than is reasonable.


We believe, and a number of well-known teachers in several of our large universities have agreed in this opinion, that this little Atlas will offer a valuable and new remedy for the difficulties stated above; and will save the student much time for real study, now often spent in getting started.


Supplied with these excellent drawings of the reconstruction, showing for the first time accurately and satisfactorily structures to be studied, the student can quickly compare his own sections with the figures of the Atlas and find the parts there clearly designated and explained.


Again, if, as is usually the case, a student has only a few cross-sections through this region the Atlas with its 48 figures of sections.


At the urgent solicitation of Professor Ph. Stohr, of Wiirzburg, Germany, Dr. F Ziegler, of Freiburg, Germany, is considering the reduplication of the model on which this atlas is based. It is expected that such models, from his studio, will be available within the year .



Florence R. Sabin, M. D


May 31, 1901.



Editor's Preface

This Atlas is planned to meet the practical need of some quick and simple, yet full and reliable, means of aiding the student to obtain, from a few sections (or from a series of sections), a reasonably clear idea of the important central relay-station of the brain here presented. (Though representing the human brain, the atlas can be applied to the study of the brains of lower mammals.)


The time allotted to a course in Neurology is generally so short; the sections to be studied exhibit such great special complexity of structure, due to the presence and association of many different centres in the narrow limits of the region; and the descriptions in text-books or lectures are commonly so detailed, or so general or diagrammatic; that many students get but hazy ideas of what is shown in their preparations, without spending more time in the effort than is reasonable.


We believe, and a number of well-known teachers in several of our large universities have agreed in this opinion, that this little Atlas will offer a valuable and new remedy for the difficulties stated above; and will save the student much time for real study, now often spent in getting started.


Supplied with these excellent drawings of the reconstruction, showing for the first time accurately and satisiactorily structures to be studied, the student can quickly compare his own sections with the figures of the Atlas and find the parts there clearly designated and explained.


Again, if, as is usually the case, a student has only a few crosssections through this region, the Atlas, with its 48 figures of sections cut in two planes and drawn to resemble actual preparations, furnishes a good supplementary series of sections for comparison.


It is thus easy to understand the many sections which are not through particularly well-marked points usually figured in textbooks; and it is possible to get a very satisfactory idea of any structure, by turning to the two series figured, to the colored plates and to the index.

Tracts in the Spinal Cord may be more readily understood and Spinal Cord traced forward into the brain with the aid of this manual.

The text not only describes, in a convenient manner and fully, everything figured in the reconstruction; but the paragraphs of small print, and others referred to in the headings and index, explain just how to compare sections with the model, and how to trace nerve-fibre tracts or masses of gray matter, from section to section through this region.


When it is realized that this model represents that part of the brain in which the nuclei of origin of all the true cranial nerves are found; that association tracts between these centres are here included; that the cells and fibre-tracts are brought into intimate association, from their central position, with those of the Spinal Cord, Cerebellum, and Forebrain; the usefulness of the Atlas to the Anatomist, Physiologist, Pathologist, and Psychologist, whether in the laboratory or in connection with lectures and demonstrations, may be seen.


A short list of text-books and journals has been included, to permit the tracing of certain tracts of nerve-fibres further up into the higher brain centres or down into the cord, and to encourage the student to seek information as to the many and varied sides of Neurology from reliable sources where more extensive references are to be found.


The Editor wishes to explain that his participation in this Atlas is confined to the suggestion of publishing the original research in the present modified new form, and to assistance in a considerable rearrangement of the text and index to facilitate ready reference. He has urged this publication in order to furnish the student, in a new and especially available form, a valuable guide to the ready interpretation of his preparations.


Henry Mc E. Knower. Anatomical Laboratory,

Johns Hopkins University.

Author's Preface

A description and the plates of a reconstruction of the medulla oblongata of the new-born babe was published in the " Contributions to the Science of Medicine," dedicated to William Henry Welch.[1] The model was built in the Anatomical Laboratory of the Johns Hopkins University at the suggestion of Dr. Franklin P. Mall and Dr. Lewellys F. Barker. It was the original thought that such a reconstruction would not only show graphically for the first time the form and relations of the tracts and nuclei, but that it would simplify for the student of anatomy a region both complex and difficult. The shape of the tracts in the cord was well known, the forms of the internal capsule in the brain could be fairly well imagined, but the tracts between the cord and brain were too complex to give mental pictures without the aid of a model. The suggestion has been made by Dr. H. Me E. Knower, of the Anatomical Laboratory of the Johns Hopkins Medical School, that the description of the model be put into a more convenient form for the student; by means of fuller references to the plates and sections; by a rearrangement of contents to make the location in the model of any set of serial sections or any single section of the region an easy matter; by adding a full index; and by a list of literature containing a few of the most important references valuable to the student at the beginning of a study of the central nervous system of man or the mammals. I am indebted to him for the arrangements for this edition.


I wish to thank Dr. John Hewetson for the material which made the model possible. Both series were unbroken, and so admirably prepared that any omissions in the model are due not to the material, but to the nature of the structures in question. I am greatly indebted to Mr. Max Broedel for the beautiful illustrations of the model. They are so accurate and clear as to be equal in value to the model itself. It is through the kindness of Dr. Henry M. Hurd that the plates of these drawings can be used for the present edition. Dr. Franklin P. Mall controlled the construction of the model, Dr. Lewellys F. Barker its study. I acknowledge with thanks their unfailing help and interest. I wish to thank Dr. John Hewetson for the material which made the model possible. Both series were unbroken, and so admirably prepared that any omissions in the model are due not to the material, but to the nature of the structures in question. I am greatly indebted to Mr. Max Broedel for the beautiful illustrations of the model. They are so accurate and clear as to be equal in value to the model itself. It is through the kindness of Dr. Henry M. Hurd that the plates of these drawings can be used for the present edition. Dr. Franklin P. Mall controlled the construction of the model, Dr. Lewellys F. Barker its study. I acknowledge with thanks their unfailing help and interest.


  1. ↑ Model of the Medulla, Pons and Midbrain of a New-born Babe, by Florence R. Sabin. Contributions to the Science of Medicine, and vol. ix of the Johns Hopkins Hospital Reports.

Contents

Chapter I. Introductory

Method Of Using Atlas

Chapter II. The Long Tracts

A. In The Medulla (Medulla Sheet)
B. In The Pons And Midbrain (Lemnisci And Formatio Reticularis)

Chapter III. The Columns Of The Spinal Cord

A. Ventrolateral Column
(A) Ventral Part
(B) Dorsal Part
B. Dorsal Column

Chapter IV. Cerebellar Peduncles

Inferior Peduncle, Or Corpus Restiforme
Superior Peduncle, Or Brachium Conjunctivum

Chapter V. The Cerebral Nerves And Their Nuclei

Median Group (Red In Model).
(A) N. Hypoglossus, XII Nucleus N., XII
(B) N. Abducens, VI Nucleus N., VI
(C) N. Trochlearis, IV Nucleus N., Iv 56
(D) N. Oculomotorius, III Nucleus N., III

Chapter VI. The Cerebral Nerves And Their Nuclei (Continued). Lateral Group

A. Motor Nerves (Red In Model)
(A) N. Accessprius, XI Nucleus N., XI.
(B) N. Glossopharyngeus Et N. Vagus, Ix And X Nucleus N., Ix And X
(C) N. Facialis, VII Nucleus N., VII
(D) N. Trigeminus, V Nucleus N., V
B. Sensory Nerves (Blue In Model)
(A) N. Glossopharyngeus Et N. Vagus, Ix And X Nucleus N. , Ix And X
(B) N. Trigeminus, V Nucleus N., V
(C) N. Vestibuli, Viii Nuclei N. Vestibuli
(D) N. Cochleae, Viii Nuclei N. Cochlese

Chapter VII. The Inferior And Accessory Olives

Chapter VIII. The Midbrain

  1. Relation Of Its Structures To The Central Fibre Mass
  2. The Nucleus Ruber (Red Nucleus) And Its Capsule
  3. The Fasciculus Retroflexus (Meynerti)
  4. The Decussatio Tegmenti Dorsalis (Meynerti)
  5. The Decussatio Tegmenti Ventralis Of Forel
  6. Stratum Album Prof Undum (Deep White Layer)
  7. Substantia Centralis Grisea (Central Gray Matter)
  8. The Pyramidal Tract
  9. Substantia Nigra

Chapter IX. The Formatio Reticularis Alba And Grisea

General Summary of what Is shown In Reconstruction

References To Literature

Figures



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An Atlas of the Medulla and Midbrain (1901): Chapter I. Introductory | Chapter II. The Long Tracts | Chapter III. The Columns Of The Spinal Cord | Chapter IV. Cerebellar Peduncles | Chapter V. The Cerebral Nerves And Their Nuclei | Chapter VI. The Cerebral Nerves And Their Nuclei (Continued). Lateral Group | Chapter VII. The Inferior And Accessory Olives | Chapter VIII. The Midbrain | Chapter IX. The Formatio Reticularis Alba And Grisea | General Summary of what Is shown In Reconstruction | References To Literature | Abbreviations | Description of Figures and Plates

Cite this page: Hill, M.A. (2024, April 25) Embryology Book - An Atlas of the Medulla and Midbrain. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Book_-_An_Atlas_of_the_Medulla_and_Midbrain

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