FROZEN SECTIONS 
 
 OF A 
 
 CHILD 
 
 BY 
 
 THOMAS DWIGHT, M.D. 
 
 INSTRUCTOR IN TOPOGRAPHICAL ANATOMY AND HISTOLOGY IN HARVARD UNIVERSITY ; FELLOW OF THE AMERICAN ACADEMY 
 OF ARTS AND SCIENCES ; SURGEON AT THE CARNEY HOSPITAL 
 
 FIFTEEN DRAWINGS FROM NATURE 
 
 BY 
 
 H. P. QUINCY, M.D. 
 
 NEW YORK 
 
 WILLIAM WOOD & COMPANY 
 1881 
 
BIOLOGY 
 
 LIBRARY 
 
 6 
 
 COPYRIGHT 
 
 WILLIAM WOOD & COMPANY 
 1881 
 
 TROW'S 
 
 PKINTING AND BOOKBINDING COMPANY 
 201-213 Kan iitA Street 
 
 NEW YORK 
 
PREFACE. 
 
 r I ^HE sections that form the basis of this little work were made, 
 with many others, during the winter of 1 880-81, to illustrate my 
 lectures at the Harvard Medical School. The sections were so in- 
 structive, and the series so perfect, that I was very anxious to have 
 them drawn and published. The subject was the body of a girl, said 
 to be three years old. The length was thirty-three inches. At this 
 age the proportions of the body, and of the organs, are no longer 
 those of the infant, and not yet those of the adult. The anatomy of 
 this, age has received little attention, and I hope that this work may 
 therefore be of use. It will serve, also, for the study of the adult 
 relations, as the peculiarities due to the age of the subject are care- 
 fully noticed in the text. I have endeavored to call attention to the 
 most important inferences to be drawn from the plates, and have 
 mentioned, incidentally, many points of anatomy which the student will 
 not find in the text-books. The reader is urged, however, to study 
 the plates carefully for himself. They are of life-size, and drawn 
 from the sections with great care and patience. The arteries were 
 injected. 
 
 Believing, as I do, that frozen sections will play an important part 
 in the anatomical teaching of the future, I shall say nothing of their 
 
iv Preface. 
 
 advantages, which speak for themselves, but will mention some of 
 their shortcomings. One would expect that they would be very well 
 suited for the study of fascise ; and so they are if you destroy the 
 specimen by removing the tissues between the fascise. Otherwise 
 you see little or nothing of them, for few fasciae are thick enough to 
 be easily distinguished when seen in~ section. Small vessels that 
 have not been injected the thoracic duct, for instance, and nerves 
 that are cut across are often made out only with great difficulty. I 
 feel it my duty to admit that there is serious doubt whether in all the 
 plates the pneumogastrics and the thoracic duct are placed quite 
 accurately in the posterior mediastinum. 
 
 My experience with frozen sections enables me to offer the fol- 
 lowing directions for making them. First, be very sure that the body, 
 or part, to be frozen is in precisely the position you desire, and that 
 there are no folds or indentations in the skin. I always use natural 
 cold when possible. Weather much above zero (Fahrenheit) is un- 
 satisfactory ; but if the part is thoroughly chilled by several days' ex- 
 posure to a pretty low temperature, a night of 10 may possibly finish 
 it. Salt and ice, or snow, no doubt, will answer the purpose, but 
 much time and patience are required. It is essential that the melted 
 ice should have a chance to run off. The body should be frozen like 
 a rock so much so that the operator cannot tell whether he is cut- 
 ting bone or muscle. Tooth is the only tissue he should be able to 
 recognize. The sections should be made in a cold room, with a very 
 sharp saw that has been chilled. When a section is cut, its surface 
 is obscured by a thick half- frozen saw-dust, which is doubly thick 
 if the freezing is not quite sufficient. It is wisest, if time allows, 
 to remove this at once, which is done by pouring a little hot water 
 
Preface. v 
 
 over the section and brushing or scraping it off rapidly and carefully. 
 This is a very delicate part of the process, and its successful perform- 
 ance has much to do with the beauty of the specimen. If it is to be 
 kept, it should be laid on a piece of glass or wood, and placed at once, 
 while still frozen, in cold alcohol. 
 
 The specimens from which these plates are made are preserved 
 at the Harvard Medical School, and are at hand to solve any doubts 
 that may arise. 
 
 To study the plates turn the book so that the vertebra is nearest 
 to you and imagine that you are looking down into your own body. 
 
 70 BEACON STREET, BOSTON, 
 July, 1 88 1. 
 
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PLATE I. 
 
 THE plane of this section inclines somewhat forward. The limits 
 of the neck are not easily defined : for, in front, the upper part 
 is hidden by the lower half of the face, and behind, the lower part 
 of the neck is indistinguishable from the back. Thus, there is but a 
 very small part of the body that is clearly neck and nothing else, and 
 this condition is particularly marked in infancy and early childhood. 
 The cut passes through the body of the sixth cervical vertebra, strik- 
 ing it in front near its upper border, where it is still cartilaginous. 
 The articular processes of the fifth cervical are seen resting against 
 those of the sixth. The essential centres of ossification of a vertebra 
 are one for the body and one for each half of the arch. They are 
 separated by the neuro-central sutures. The direction of these sutures 
 is modified by the presence of a double transverse process in the cer- 
 vical region. A more correct idea of them is obtained from PLATE V., 
 where they cut off merely the posterior angles of the body. They 
 disappear from the fourth to the sixth year. A glance at PLATE X. 
 will show that ossification is completed sooner in the lower part of 
 the column. The vertebral artery is seen in its foramen. In front of 
 it is the projection known as the tubercle of Chassaignac, which is a 
 characteristic of die sixth vertebra, and sometimes used as a guide 
 to the carotid. 
 
 The intervertebral discs form 41.9 per cent, of the length of the 
 cervical region of the adult spine, the mean length of this region be- 
 ing 13.6 ctm. It forms 22.5 per cent, of the length of the column above 
 the sacrum. In the very young embryo, the neck forms one-third 
 of the spinal column (above the sacrum) and the lumbar region one- 
 fifth. In the adult these proportions are pretty nearly reversed. This 
 change begins very early, for at birth the lumbar region is longer than 
 the cervical. At three years the proportionate length of the cervical 
 region is a little greater and that of the lumbar a little less than in 
 
: ; Frozen Sections of a Child. 
 
 the adult. 1 The shortness of the neck in infancy does not, therefore, 
 depend on that of the cervical region of the spine, but on the large- 
 ness of the head, the high position of the sternum, and the abun- 
 dance of fat. 
 
 The sixth cervical nerve is seen leaving the spinal canal, which 
 is broad to contain the cervical enlargement. It is well to remember, 
 that as there are eight cervical nerves and only seven vertebrae, 
 each of the first seven passes above the vertebra of the correspond- 
 ing number, and in the other regions the nerve passes under its ver- 
 tebra. The nerves do not arise from the cord opposite their points 
 of exit, but somewhat higher ; suffice it to say, for the cervical region, 
 that the eight nerves are all given off above the fifth, or certainly the 
 sixth, spine, which is about on a level with the body of its vertebra. 
 The fifth nerve and a branch of the fourth are seen between the 
 scalenus anticus and medius on their way to the brachial plexus. The 
 phrenic is just in front of the former muscle, which it follows down to 
 the thorax. This nerve arises from the fourth cervical, but almost al- 
 ways receives fibres from the fifth, though at very uncertain points. 
 
 The trachea is divided a little below the cricoid, probably through 
 the first ring. This, therefore, is the important region of trache- 
 otomy. The isthmus of the thyroid appears to be rather large ; 
 usually it covers the three rings after the first, 2 but it is extremely 
 variable, and may be wanting. The left lobe reaches to the oesopha- 
 gus, and slightly overlaps the carotid. It is easy to see how, if en- 
 larged, it might make its way between the artery and the vein, as is 
 said sometimes to be the case. The oesophagus, cut just below its 
 origin, already inclines to the left. The recurrent laryngeal nerves 
 lie in the angles between it and the trachea. 
 
 The muscular masses and the general arrangement of the fasciae 
 are easily understood. The superficial muscular layer, omitting the 
 platysma, consists of the sterno-mastoids and the trapezii. They are 
 both supplied by the spinal-accessory nerve, with some assistance 
 from the spinal nerves. It is a mistake to suppose that the sterno- 
 mastoids bow the head. As they are attached behind the transverse 
 axis of the occipital joints, they would tend to throw the face upward. 
 The action of one of them is to turn the face to the other side. Thev 
 
 1 Aeby : Archiv. fur Anatomic und Entwickelungsgeschichte, 1879. 
 
 2 Pilcher : Annals of Anatomy and Surgery, April, 1881. 
 
Frozen Sections of a Child. 9 
 
 are very powerful muscles, and their chief work probably is to hold 
 the head and neck firm. The trapezii and the sterno-mastoids are 
 both inclosed in the cervical fascia, which extends from the ligamen- 
 tum nuchae to the median line, and splits to receive them. From the 
 deep surface of this fascia, in the anterior region, there pass off a 
 number of layers, making sheaths for the smaller muscles, joining the 
 capsule of the thyroid and the sheaths of the great vessels. The 
 sheath of the carotid must not be considered as a membranous tube, 
 but rather as a collection of dense areolar tissue surrounding the ar- 
 tery, vein, and nerve, and running in between them. The vein is 
 seen at the outside of the artery, and the nerve behind ; on the left, 
 between them. The small size of the vein compared to that of the 
 artery is due to the latter being injected and the former empty. The 
 omo-hyoid lies at this level on the outside of the vessels. The pre- 
 vertebral fascia, binding down the longi colli, and passing over the 
 scaleni, is a very distinct structure. The levator anguli scapulae lies 
 behind the scalenus medius, beneath the fat at the side of the neck. 
 It slightly overlaps the splenius. In rotary motions of the head each 
 splenius may act with the sterno-mastoid of the opposite side. It is 
 very likely, however, that slight rotary motions are made chiefly by 
 the group of small muscles below the occiput. 
 
 The external jugular veins are seen at the rear edge of the ster- 
 no-mastoids, outside of the fascia. The anterior jugular is normally 
 outside of the fascia : it may be single or double. It opens into the 
 subclavian vein, or, especially in the latter case, may be connected 
 with both by a transverse vein just above the sternum. The deep 
 plexus of veins in front of the trachea, somewhat below this level, 
 comes from the thyroid body, and empties into the left innominate 
 vein. 
 
PLATE II. 
 
 THIS plane is nearly level antero-posteriorly, though perhaps the 
 front is still a little the lower, its distance below the preceding 
 plate being about 2 ctm. We see the lower part of the first dorsal 
 vertebra, and, apparently behind it, owing to the curve of the spine, 
 a part of the intervertebral disc. The arch and pedicles belong 
 to the second dorsal. By remembering that two ribs rest, in 
 part at least, against the first dorsal, we know that till we approach 
 the lower end of the dorsal region the head of each rib touches 
 the upper border of the corresponding dorsal vertebra. Thus 
 we see the beginning of the second rib on both sides at its origin, 
 and the first rib cut obliquely as it descends to the sternum. The 
 relations may fairly be called normal, even for the adult, as there is 
 a great deal of variation in the height of the top of the sternum and 
 in the consequent inclination of the plane of the top of the thorax. In 
 this case the upper end of the sternum is opposite the lower part of 
 the second dorsal vertebra. This is, perhaps, higher than usual. 
 The lungs are seen rising above the clavicles ; the left one ap- 
 pears the larger, although the section is a little higher on that 
 side. They reach to about the level of the head of the first rib. 
 Usually there is little difference in the height of the apices which lie 
 far back in the cage formed for them by the upper ribs. The general 
 course of the first rib to the sternum, from the point at which it is di- 
 vided, can easily be imagined. The pleura extends obliquely forward 
 to the margin of the rib beneath the structures which appear between 
 the lungs and the clavicles. The scaleni antici 1 are important land- 
 marks. They reach the first rib a little below this section. The 
 
 1 They are not named in the plate, but are to be seen on each side between the two lines 
 that converge from different parts of the subclavian artery. 
 
1 2 Frozen Sections of a Child. 
 
 phrenic nerve is still in front of each, but gradually working its way 
 to the inner side of the muscle. The subclavian vein is seen in front 
 of the muscle on the right side, but on the left it is just too deep. The 
 subclavian artery and the brachial plexus cross the first rib behind this 
 muscle and before the scalenus medius. According to Zuckerkandl 1 
 the artery and the plexus are generally separated by the scalenus 
 minimus (long known as an anomaly), which arises from the trans- 
 verse processes of the sixth and seventh cervical vertebrae, or the 
 latter only, and from the upper border of the first rib. It runs to be 
 inserted into the same rib between the structures just mentioned, but 
 it is attached also to the top of the pleura. Its chief purpose appa- 
 rently is to strengthen and tighten the latter. Sometimes the place 
 of the muscle is taken by fibrous bands, which, indeed, had been ob- 
 served by Sibson. 
 
 The cervical portion of the thymus, which often reaches to the 
 thyroid, lies in front of the trachea and great vessels. The innominate 
 divides just below the surface of this section, rather above the right 
 sterno-clavicular joint. The left carotid is on the left of the trachea, 
 and the left subclavian far back beside the oesophagus. The cut ends 
 of both subclavian arteries show clearly how they arch over the lung, 
 resting on the pleura. The internal mammary artery and vein lie in 
 the angle between the right subclavian and the scalenus anticus. On 
 the left, only the artery is seen beside the muscle. The internal jug- 
 ular appears on both sides, but the subclavian vein only on the right. 
 The innominate veins begin just below the section. The right pneu- 
 mogastric nerve runs directly before the subclavian artery, being still 
 behind and between the carotid and jugular. The left one is nearly 
 in front of the carotid. The left recurrent laryngeal nerve runs in the 
 angle between the trachea and oesophagus, but the right one, which 
 is given off just in front of the subclavian, has not yet had time to get 
 there, and is seen behind the artery. 
 
 We can now resume the study of the cervical fascise. The an- 
 terior layer splits below the thyroid into one going to the front of the 
 sternum, and into a stronger one passing to its posterior surface. It 
 is seen separating the sterno-hyoids and thyroids from the sternal 
 insertions of the sterno-mastoids. This deeper layer gives off the 
 important expansion that passes from the posterior belly of the omo- 
 
 1 Zeitschrift fur Anatomie-und Entwickelungsgeschichte, Band II. 
 
Frozen Sections of a Child. 13 
 
 hyoid to the clavicle and the first rib. It then invests the subclavius 
 (which is seen on the outer side of both clavicles), and extends from 
 the first rib to the coracoid process. This well-defined fascia is called 
 the costo-coracoid membrane. It is continued into the axilla, forming 
 the front portion of the sheath of the axillary vessels ; the remainder is 
 formed by another prolongation of the deep cervical fascia. The pre- 
 vertebral fascia is very dense in this region. Strong prolongations 
 arise from it opposite the lower cervical and the upper dorsal verte- 
 brse and are attached to the roots of the lungs, but more particularly 
 to the front and back of the pericardium, and thus indirectly to the 
 diaphragm. They may be called its suspensory ligaments, and pre- 
 vent any serious sinking of its tendinous centre. 1 The pericardium is 
 attached also to the sternum by areolar tissue, among which certain 
 bands may be distinguished, named by Luschka the superior and in- 
 ferior sterno-pericardiac ligaments. 
 
 The upper part of the left shoulder-joint is opened, and but a 
 small piece is taken off from the head of the humerus. The beginning 
 of the acromion is behind it, and on the inner side the upper surface 
 of the root of the coracoid is seen. The superior angle of the scapula 
 is behind the angle of the second rib, and its posterior border ends 
 immediately above PLATE V. Its relations, therefore, are the same 
 as in the adult : it covers the ribs from the second to the seventh in- 
 clusive. On the right the cut falls decidedly lower, striking the glenoid 
 cavity, the coracoid, and the greater tuberosity of the humerus. The 
 long head of the biceps runs on this side through its sheath in the wall 
 of the capsule, but on the left it is seen inside the joint running over 
 the head of the humerus. The trapezius, deltoid, and pectoralis major, 
 are all parts of one muscular layer. On the left, the cephalic vein is 
 seen just after it has pierced the fascia between the two latter. This 
 plate and the next show how liable the deltoid is to injury in severe 
 blows or falls on the shoulder. It is quite as likely that its very fre- 
 quent wasting in such cases is due to direct injury to the muscle as to 
 the circumflex nerve that supplies it. The supra-spinatus is seen on 
 both sides, divided before its insertion. In the specimen, though not 
 in the plate, fibres of the infra-spinatus may be distinguished mingling 
 with the capsule of the right shoulder. It is worth while to remember 
 how high up on the greater tuberosity these rotators are inserted. 
 
 1 Teutleben : Archiv fur Anatomic und Entwickelungsgeschichte, 1877. 
 
14 Frozen Sections of a Child. 
 
 The serratus magnus is well shown beneath the scapula, which 
 it holds firmly in place. It is supplied by the long thoracic nerve. 
 Its paralysis allows the posterior border of the scapula to fall outward 
 " angel palsy." A somewhat similar result follows paralysis of the 
 trapezius, but the eversion of the shoulder is less marked and its fall- 
 ing greater. The supra-scapular artery is seen on the left, passing 
 over the upper border of the scapula. 
 
PLATE III. 
 
 THIS is a little less than 2 ctm. below the preceding, and very nearly 
 level. The reader is referred to the plate for the identification 
 of the vertebrae and ribs. The cartilage on the side of the sternum 
 is an expansion from that of the first rib, which in children may 
 reach nearly to the cartilage of the rib below it. The manubrium is 
 divided in its lower half. The second rib, bone and cartilage, con- 
 tinues nearly horizontally from the point at which it is divided to its 
 insertion. The cartilages of the following ribs, excepting the last 
 two, have both a falling and a rising portion. Braune states that at 
 about this level the antero-posterior diameter of the chest equals one- 
 third of its breadth, while in the new-born child it is one-half. In a 
 man of fifty, however, he found the proportion i to 2.5, which is very 
 nearly that of this subject. That, however, was probably an indi- 
 vidual peculiarity, and the shape of the thorax at three, seems to be 
 intermediate between that of the infant and the adult. 
 
 A great deal more lung-tissue is seen here than in the preceding 
 plate. The pleurae are still far apart, not quite reaching the borders 
 of the sternum. Between them we have the anterior mediastinum 
 filled with areolar tissue, bounded by the sternum in front and the 
 aorta and vena cava behind. Between the latter and the trachea is 
 found a large part of the thymus, which is peculiarly situated, as it is 
 not common for it to extend so far back. It is seen again in PLATE 
 IV. in the anterior mediastinum. This organ is not rarely found in 
 the young adult. According to Riidinger, its involution does not be- 
 gin till the fifteenth year. The great fissure of the lungs begins on 
 the left, a little above this section, and on the right just below it. The 
 bifurcation of the trachea is seen opposite the lower border of the 
 fourth dorsal. This is practically its adult position in regard to the 
 spine, though it is often said to be higher. In this child it must be 
 rather below than above the junction of the first and second pieces of 
 the sternum. The thoracic duct lies on the left of the oesophagus ; it 
 arches forward a little above this, and was not found in the preceding 
 
1 6 Frozen Sections of a Child. 
 
 sections. It may rise as high as the thyroid body before returning 
 to its end at the junction of the left jugular and subclavian veins, 
 or it may rise hardly at all above that point. The innominate veins 
 are not seen, as they run in the thickness of the slice above this plate, 
 and unite to form the vena cava superior opposite the lower half of 
 the cartilage of the first rib, at the right border of the sternum behind 
 the thymus. As the cava descends, it inclines backward, so that in 
 PLATE IV. it is behind the aorta, but, owing to the spiral course of the 
 latter, it is beside it again at its termination just above the level of 
 PLATE V. 
 
 The course of the oesophagus deserves a special description. 
 Just below its origin it begins to incline to the left, as is shown in PLATE 
 I. The deviation is more marked in PLATE II., but in the next, oppo- 
 site the third and fourth dorsal vertebrae, it is driven back toward the 
 middle by the arch of the aorta. It continues for some distance near 
 the median line. Opposite the ninth dorsal it is well to the right, 
 but it then begins to sweep forward and to the left. It ends opposite 
 the lower part of the tenth dorsal. 
 
 In another child, of about the same age, examined by means of 
 similar sections, the gullet at the top of the first dorsal was completely 
 on the left of the trachea, which rested against the prevertebral fascia. 
 It continued on the left, passing behind the left bronchus, till it regained 
 the middle line opposite the seventh dorsal. It then ran to the left 
 again, in front of the descending aorta, and ended at about the upper 
 border of the eleventh dorsal. In this case there was an effusion in 
 the right pleural cavity. Braune states that the greatest deviation to 
 the left is in the region of the second and third dorsals ; Tillaux, that 
 the general direction is to the left, but that it is slightly deflected to 
 the right, opposite the third dorsal, by the arch of the aorta. An ex- 
 amination of sections by Pirogoff, Braune, Riidinger, and Henke, 
 shows that there is great individual variation. Whether pleuritic ef- 
 fusions can displace the gullet, is important, but unsettled. One point 
 seems reasonably certain, that at the bifurcation of the trachea it 
 usually passes behind the left bronchus, and, as far as I know, never 
 behind the right one, excepting when all the viscera are transposed. 
 Muscular fibres frequently pass from the left bronchus to the oesopha- 
 gus, and in nine cases in which Gruber 1 found a muscle arising from 
 the right bronchus, in every one its fibres ran from the bronchus di- 
 
 1 Reichert und Du Bois Reymond's Archiv., 1869. 
 
Frozen Sections of a Child. \ 7 
 
 rectly or obliquely to the left. Various other irregular muscular bun- 
 dles connect the gullet with the pleurae and pericardium. The aorta 
 is in close connection with the oesophagus for a great part of its 
 course. This we shall return to. PLATE V. shows the relations to 
 the left auricle and right pulmonary vein to the oesophagus. 
 
 The views of the intra-thoracic nerves in Plate III. are very in- 
 structive. The phrenics are seen far forward, especially the left one, 
 which lies between the opposed surfaces of the pericardium and 
 pleura. The right, which has not yet reached a corresponding posi- 
 tion, lies behind the vena cava. The right pneumogastric has joined 
 the oesophagus ; the left one, at the left of the arch of the aorta, gives 
 off the recurrent laryngeal, which emerges between the aorta and 
 trachea. The phrenics pass in front of the roots of the lungs ; the 
 pneumogastrics behind them, as is clearly shown in PLATE IV. The 
 pericardium is seen covering the right anterior surface of the ascend- 
 ing aorta. The course of that vessel is left for the next chapter. 
 
 The left scapula is cut just under the glenoid cavity, the right 
 one lower still. In both cases the joint is opened where the cap- 
 sule hangs down in a fold, which is obliterated when the arm is 
 raised. A small bursa is found on each side between the humerus 
 and the pectoralis minor. The subscapularis and the infra-spinatus, 
 separated by the body of the scapula, are easily known. The teres 
 minor lies against the latter muscle. On the right, the long head of 
 the triceps, represented too much like fibrous tissue, runs along the 
 anterior border of the scapula. On the left it becomes muscular at 
 once, and is seen outside of the teres minor. 
 
 The axilla is shown as a small space, containing the large vessels 
 and nerves, surrounded by areolar and fatty tissue. It is bounded on 
 the inside by the chest- wall, in front by the lesser pectoral, on the out- 
 side by the coraco-brachialis, and behind by the subscapularis. Its lower 
 wall is formed by the skin, which is held close up by the axillary fascia. 
 The axilla ends above by the convergence of its walls (PLATE II.). 
 
 The trapezius is slightly shaded in this plate. Below are the 
 rhomboids, running to the posterior border of the scapula. It is im- 
 portant to know that there is a small space under the scapula, usually 
 containing a little fat, bounded by the chest-wall, the rhomboid, and 
 the serratus. Pus occasionally is found in it, and as the serratus does 
 not allow the abscess to point in the axilla, it may attain a large size 
 and give much pain before it is recognized. 
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PLATE IV. 
 
 THIS is about 1.8 ctm. below the preceding surface, and slightly 
 nearer to it in front than behind. It is, however, practically 
 horizontal, and falls just below the axillae. The apex of the spine of the 
 fifth dorsal appears on a level with the lower part of the body of that 
 vertebra. The second piece of the sternum is divided just above the 
 third cartilage. The cartilage of the second rib just touches this 
 plane, showing that in this instance, at least, it describes a curve, 
 though a slight one. 
 
 This plate and its two neighbors show admirably the relations of 
 the great vessels and of the roots of the lungs. The pleurae nearly 
 meet behind the sternum, where they overlap the thymus. -The peri- 
 cardium is opened widely above the auricles. It is folded in between 
 the aorta and the vena cava, follows the former till it begins to turn 
 backward, and passes round the front and side of the pulmonary 
 artery. 
 
 The pulmonary artery and the aorta are twisted round one an- 
 other. The former arises not quite in front of the latter, as is some- 
 times taught, but a little more to the left, behind the left border of 
 the sternum at the lower edge of the third cartilage. The auricular 
 appendages hang on either side of it. One of its valves is behind, 
 two in front. The vessel runs upward, backward, and slightly to the 
 left, dividing beneath the aortic arch opposite the junction of the car- 
 tilage of the second rib to the sternum. The right division is seen 
 in this plate, the left is higher. The aorta arises lower, the central 
 point of its lumen at its origin being a little above the plane of PLATE 
 V., behind the sternum, on a level with the upper border of the fourth 
 cartilage. This is a very little lower than it is usually placed, namely, 
 opposite the third intercostal space, or even the third cartilages. 
 The aortic valves have been described in various ways. There are 
 two behind and one in front. The right one of the former and the 
 
20 Frozen Sections of a Child. 
 
 greater part of the latter are seen in PLATE V. The third is at a 
 higher level. I have followed Sibson's * nomenclature, but it seems 
 as if it would be quite as well to say that there is a superior one on 
 the left, and two inferior on the right. One of the sinuses of Val- 
 salva corresponds with each flap. The superior sinus is the largest ; 
 it gives off the left coronary artery. The right artery springs from 
 the anterior sinus. The aorta runs forward, upward, and to the right. 
 In PLATE IV. the pulmonary artery is on its left, and the superior 
 cava almost behind it. At this plane it changes its direction and runs 
 more distinctly forward and to the left. In PLATE III. it is behind the 
 sternum at the height of the first intercostal space. It is seen in this 
 section arching over the root of the left lung, and we -may infer that 
 the highest point of the arch is opposite the top of the third dorsal 
 vertebra and below the top of the sternum. Inasmuch as these two 
 points are in no constant relation to each other, we must consider 
 what is the proper position of the top of the arch with regard to each. 
 Sibson 2 found the top of the arch in one instance one and one-half 
 inch below the top of the manubrium, and in another one-half inch 
 above it. In five cases he found it above, and in six on a level with 
 the top of the sternum, while in seven it was quite an inch below it. 
 " In two-thirds of the instances (thirty in forty-eight), however, the 
 top of the aorta occupied an intermediate place behind the upper half 
 of the manubrium, its average position being half an inch below the 
 top of the bone." The position of the highest point of the arch on a 
 level with the upper part of the third dorsal vertebra is rather higher 
 than is normal in the adult, 3 although good text-books place it as high 
 as the second. The rapid decrease in size of the arch of the aorta 
 is partly real and partly apparent. It becomes smaller after giving 
 off the great arterial branches, and, moreover, the section strikes it 
 below its greatest diameter. The descending aorta proper begins 
 between PLATES III. and IV., say between the fourth and fifth dorsals. 
 The close relation of the aorta to the cesophagus from this point to 
 the diaphragm should be carefully noticed. The aorta, which in 
 PLATE IV. is quite on the side of the spinal column, gradually passes 
 
 1 The Position and Form of the Heart and Great Vessels. Reynolds' System of Med- 
 icine. Vol. IV. 
 
 2 Loc. cit. 
 
 3 Mr. J. Wood : The Topographical Relations of the Arch of the Aorta and the Posterior 
 Mediastinum to the Spinal Column. Journal of Anatomy and Physiology. Vol. III. 
 
Frozen Sections of a Child. 2 1 
 
 in front of it, getting behind the gullet, as is shown in PLATES VI. and 
 VII. It runs through the diaphragm below PLATE VIII., opposite 
 the twelfth dorsal vertebra. 
 
 The root of the lung is composed of the bronchus, blood-vessels, 
 nerves, and lymphatics. The most important of these structures are 
 seen in PLATE IV. The right bronchus is larger than its fellow, 
 which is normal, and appears to descend more rapidly, which is not. 
 On the right, the right branch of the artery is in front of the bronchus, 
 and a branch of the superior vein before that. On the left the vein 
 is in front of the bronchus, and the artery behind ; but if the section 
 had been made a little higher the story would have been different, 
 for the left pulmonary artery would have been seen arching over the 
 bronchus, and but little of the vein would have been seen. PLATE V. 
 shows the lower right pulmonary vein opening into the left auricle. The 
 left one is cut while it is rising toward the heart. In fact, each of the 
 left pulmonary veins opens into the heart somewhat above its fellow. 
 According to the usual description, the order from above downward 
 is as follows : on the right, bronchus, artery, veins ; on the left, ar- 
 tery, bronchus, veins ; and from before backward on both sides, veins, 
 artery, bronchus. This order from above downward is in the main 
 correct, but in the other direction it can include only the superior pul- 
 monary veins, for PLATE V. shows clearly that the inferior ones can- 
 not be in a plane anterior to that of the arteries. 
 
 A mass of enlarged and degenerated glands lies beneath the 
 bifurcation of the trachea. This, together with the bronchi, forms at 
 this level the front wall of the posterior mediastinum. The lateral 
 walls are formed by folds of the pleurae. The contents are the aorta, 
 the oesophagus, with the pneumogastric nerves, the thoracic duct, and 
 the vena azygos. It contains, also, sympathetic nerves, but they were 
 not recognized. The vena azygos arches over the root of the right 
 lung to join the vena cava just above the pericardium. It constitutes 
 a very important connection between the systems of the upper and 
 lower venae cavse. 
 
PLATE V. 
 
 THIS represents a pretty even section, 1.8 ctm. below the pre- 
 ceding one. Three vertebrae are shown. The body of the 
 seventh dorsal is cut about the middle. The arch belongs to the 
 same vertebra, but the articular processes of the eighth appear be- 
 fore it ; and behind is the tip of the spinous process of the sixth. 
 
 The dorsal region forms 47.6 per cent, of the spine above the 
 sacrum, and keeps very nearly the same relative length in the embryo 
 and throughout life. Its mean length in the adult is 28.5 ctm. The 
 intervertebral discs constitute a little more than a quarter 26.4 per 
 cent. of the dorsal region. The eighth rib is just below the plane of 
 the section on the left, and still deeper on the right. The third rib 
 is shown on the right just where it joins its cartilage. The latter 
 rises very rapidly as it approaches the sternum. This bone is cut 
 where the fourth cartilages join it between its third and fourth pieces. 
 The scapulae end just above this plane. The differences between the 
 relations of the antero-posterior and the transverse diameters of the 
 thorax of the child and of the adult are much more marked at about 
 this level than at the highest part of the cavity. Thus, in this plate, 
 the former diameter is to the latter about as i to 2, while in the adult 
 it varies from as i to 2.5 to as i to 3. At birth it is nearly as 2 to 
 3. The nipple is on the front wall of this slice opposite the fourth 
 rib on both sides. Luschka found it in the fourth intercostal space 
 forty-four times out of sixty in males. In women it is said to be op- 
 posite the fifth rib ; but, owing to the great variety of forms and sizes 
 of the breast, it is of no constant value as a landmark in women. 
 
 This cut is a remarkably fortunate one, for it has struck the heart 
 so as to open its four cavities, and to show both the valves of the left 
 ventricle. Three-fourths of the heart, as seen in this plate, belong 
 
24 Frozen Sections of a CJiild. 
 
 to the left side, and both this view and the next show how this ap- 
 pears to be the important side of the heart, and the right merely an 
 addition to it ; yet before birth the two sides are of about equal 
 strength. The conus arteriosus, a prolongation upward of the right 
 ventricle to the pulmonary artery, is nearly in front of the aortic 
 valves, two of which appear in this plate. Behind them is the mitral 
 valve, consisting of two segments an anterior one on the right, a 
 posterior one on the left. The valve is closed ; it lies behind the left 
 border of the sternum, and at this level is opposite the fourth cartil- 
 age. There was some difficulty in defining its limits quite accurately, 
 but they seem to correspond very well with the normal ones of the 
 adult, namely, from the third space to the fifth cartilage. The pul- 
 monary valves are higher than the aortic, which are higher than the 
 mitral, and the tricuspid is the lowest. No one of these valves, how- 
 ever, is completely above the one next below it they all overlap. 
 The left auricle appears in this plate to deserve to be called the pos- 
 terior one, but PLATE IV. shows it extending forward on the left. 
 
 The pleural cavities are about as near together behind the 
 sternum as in the preceding plate, but the left lung makes way for 
 the heart. Usually, a needle thrust through the fifth or sixth inter- 
 costal space, and sometimes through the fourth at the left border of 
 the sternum, will pierce the pericardium and not the pleura. The 
 great fissure of the left lung begins rather above the head of the 
 fourth rib, that of the right rather below it. The third, or middle, 
 lobe of the right lung is shown in PLATE V. It varies in size and 
 shape, according as the fissure that forms its upper boundary runs 
 upward from the main fissure from which it springs, directly forward, 
 or downward, as in this case. As a rule, the main fissure usually 
 strikes the lower surface of the lung, so that the front of the lung is 
 formed entirely by the upper lobe, or by the upper and middle lobe 
 on the right. 1 In this case the middle lobe is a tongue-shaped body 
 of little consequence, and the upper lobes form but a very small part 
 of the base of both lungs. 
 
 An extra lobe of the right lung may be formed by the abnormal 
 course of the vena azygos, which makes a groove in the top of the 
 
 1 Dr. Cilley, of Cincinnati, has the credit, I believe, of being the first to call attention to 
 this in any publication in English. Vide Cincinnati Lancet and Clinic, 1881. The fact was, 
 however, already known to German anatomists. 
 
Frozen Sections of a Child. 25 
 
 lung as it runs to open into the superior cava near its beginning in- 
 stead of near its end. 1 Chiene describes a case in which the vena 
 azygos left the spine at the fifth dorsal vertebrae, and, running in the 
 edge of a fold of pleura, cut out an extra pear-shaped lobe in the right 
 lung, which had its origin in the angle formed by the junction of the 
 upper lobe with the root of the lung. 2 
 
 1 Gruber : Bulletin de I'Academie de St. Petersburg. Vol. XV. 1871. 
 ' 2 Journal of Anatomy and Physiology. Vol. IV. 
 
 4 
 

PLATE VI. 
 
 THIS is 1.8 ctm. below the preceding. The cut runs, perhaps, a 
 little obliquely, so as to strike the front wall of the chest a little 
 higher than it should. There, however, is no serious error in assum- 
 ing that the section is a true one. We are struck at once with a 
 peculiarity depending on the age of the subject. The disc between 
 the eighth and ninth dorsal vertebrae appears on a level with the be- 
 ginning of the ensiform cartilage, which is seen just behind the carti- 
 lages of the seventh ribs, which are about to meet. In the adult of 
 either sex the sternal end of the seventh pair of ribs would be found 
 opposite a lower point. Luschka places them opposite the vertebral 
 end of the eleventh pair. A horizontal section by Braune, through the 
 upper part of the ninth dorsal vertebrae, strikes the sternum at the 
 sixth intercostal space. A comparison with other sections leads to 
 the belief that the latter is a more usual relation than Luschka's. 
 The relations of the sternum in this child correspond remarkably with 
 those of the adult till we reach the lower part of the body of the ster- 
 num, which is smaller than it should be, so that the fifth, sixth, and 
 seventh ribs are crowded together at their sternal ends. 
 
 The sternum varies extremely in length and in the relative size 
 of its parts. Tillaux states that it increases with the height of the 
 body, but that many exceptions occur both of which statements agree 
 with my observations. Hyrtl states very certainly that "the manu- 
 brium of the female sternum exceeds half the length of the body, while 
 the body of the male sternum is at least twice as long as the manu- 
 brium." I found that this did not apply to the breastbones of twelve 
 men out of thirty, nor to those of fourteen out of twenty-six women. 
 The male sternum is usually decidedly larger than the female. The 
 above-mentioned measurements give a mean of 5.18 ctm. for the male 
 manubrium, and of 4.67 ctm. for the female ; of 10.59 ctm. for the body 
 
28 Frozen Sections of a Child. 
 
 of the male sternum, and of 8.94 ctm. for the female. 1 The history of 
 the development of the sternum has not been thoroughly studied. I 
 believe that the lower part of the body of the bone is proportionally 
 small in early childhood, which occasions discrepancies with the rela- 
 tions of the adult, as occurs in this subject. 
 
 The upper surface of the diaphragm, separating the right lung 
 from the liver, is just grazed in this section. The view of the heart 
 shows the right auricle resting on the liver, the right ventricle, and 
 the lower posterior wall of the left one. The apex is seen in PLATE 
 VII. In the section before us, the lower segment of the tricuspid is 
 seen lying on the lower wall. The other two are placed higher, one 
 attached to the front wall, the other to the septum. It is not easy to 
 define accurately the position of the valve, but we may say that it lies 
 behind the lower fourth of the sternum, and that its upper border 
 probably does not quite reach the level of the fourth cartilage, as it 
 should. The floor of the right auricle presents nothing of interest, 
 excepting the remains of the Eustachian valve, the edge of which ap- 
 pears as a line in front of the orifice of the vena cava inferior. It is 
 easy to see, by looking at PLATE V., how this valve, when more de- 
 veloped, as in intra-uterine life, would direct the current toward the 
 fenestra ova.lis, which must have been in the oblique inter-auricular 
 septum, the top of which is seen in that plate. The vena cava inferior 
 passes through the tendinous part of the diaphragm opposite the 
 lower part of the body of the ninth dorsal vertebra. It is kept widely 
 distended by its firm attachments to the diaphragm. Thus, even at 
 this age this vein exists as a distinct vessel above the diaphragm. At 
 birth it opens into the heart almost immediately after passing the 
 foramen. In the adult the vessel runs upward and bends toward the 
 left. As the foramen through the diaphragm is about horizontal, and 
 the opening into the heart nearly vertical, it follows that the posterior 
 and right surface of the vein is longer than its anterior and left one. 
 According to Luschka, the former is 3.8 ctm., the latter 2. 2 ctm. The 
 vein contains no muscular fibres above the diaphragm, but fibres from 
 the heart end tendinously in its walls, apparently to expand, not to 
 constrict it. It is covered by the pericardium in its upper two-thirds. 
 
 We will now endeavor to define the position of the heart. The 
 apex is on a level with the upper border of the cartilage of the sixth 
 
 1 Journal of Anatomy and Physiology. Vol. XV. 1881. 
 
Frozen Sections of a Child. 29 
 
 rib at its most dependent part, 3.2 ctm. below the nipple, and at least 
 i ctm. inside of it. The lower end of the auriculo-ventricular groove 
 is at the right of the base of the ensiform cartilage, opposite the car- 
 tilage of the sixth rib as it rises to join the sternum, and about i ctm. 
 to the right of the median line. The lower border of the heart would 
 be represented by a slightly curved line connecting these points. The 
 auriculo-ventricular groove runs upward to the middle of the line be- 
 tween the cartilages of the third ribs. The right auricular appendage 
 is seen rather above that level in PLATE IV., and in the same plate the 
 left auricle, which constitutes, perhaps, the highest point of the heart, 
 is opposite the lowest part of the second intercostal space at the side 
 of the sternum. The position of the heart is, therefore, practically 
 normal, even for the adult. The apex 1 is rather lower than usual in 
 relation to the ribs, but possibly this would have been corrected as 
 the lower part of the sternum became more developed. The greatest 
 breadth of the heart is seen in PLATE VI., and more of the heart lies 
 in contact with the chest than at the level of any other plate. 
 
 The pericardium rests upon the central tendon of the diaphragm, 
 but it extends over on to the muscular part both to the right and the 
 left. The attachment of the front wall of the pericardium to the dia- 
 phragm is particularly firm. 
 
 This plate shows a change in the shape of the posterior medias- 
 tinum, which is caused by the aorta having made its way to the front 
 of the column, crowding the oesophagus and the vena azygos to the 
 right. 
 
 1 " The lower edge of the apex was on a level with the lower edge of the left fifth carti- 
 lage in one-seventh of the instances observed (six in sixty-nine) ; it was below that edge in 
 two-fifths of them (twenty-six in sixty-nine) ; and it was above that edge in almost one-half 
 of them (thirty-four in sixty-nine). In five instances the lower boundary of the apex was 
 situated one inch above the lower edge of the fifth cartilage, and in four it was fully one inch 
 below that edge." Sibson : loc. cit. 
 
-T- 
 
PLATE VII. 
 
 AN even section about 1.6 ctm. below the last. It shows impor- 
 tant relations in both the thoracic and abdominal regions. The 
 diaphragm is seen separating the cavities, except in front, where it 
 passes for a short space above this section. The oesophagus, now in 
 front of the aorta, opens just below the level of this section, opposite 
 the lower half of the tenth dorsal. In the adult its termination is 
 placed from the ninth to the eleventh. The apex of the heart is di- 
 vided just at the lowest point of the cavity of the left ventricle. Only 
 a very small pericardial cavity is seen around it. The lower edge of 
 the right lung is seen behind the liver, and that of the left behind 
 the spleen. A very small piece of the left lung appears also, outside 
 of the apex of the heart, under cover of the sixth rib. The posterior 
 borders of the lungs extend about 6 mm. below this plane. They 
 are, therefore, below the tenth rib at its angle. In the mammillary 
 and axillary lines they end very near the level of PLATE VII. The 
 lungs are, of course, in a state of complete expiration, and smaller 
 than they probably can be during life, but one of the merits of a fro- 
 zen section is that it shows them in much more normal relations than 
 they would present if the chest were opened in the usual way, which 
 would occasion their collapse. The pleural cavities extend consider- 
 ably lower. They do not, however, follow the diaphragm into the 
 angle which it forms with the cartilages of the six lower ribs ; the 
 very lowest part of this space is filled with areolar tissue. The 
 pleura is described as reaching in the mammillary line to the cartilage 
 of the sixth, sometimes of the seventh rib ; and in the axillary line, 
 to the lower border of the ninth rib on the right, and of the tenth on 
 the left. It does not touch the cartilages of the four or five lower ribs. 
 Let us compare this general description with this individual, case. 
 In PLATE VIII. the front of the pleural cavity reaches about to the 
 mammillary line. On the left, it lies against the seventh cartilage 
 
32 Frozen Sections of a Child. 
 
 near its lowest point. On the right it lies against the bony part of 
 the same rib. (The right of this section is higher than the left.) In 
 PLATE IX. it reaches the tenth rib on both sides, at a point not far 
 from the axillary line. It lies behind both kidneys, but covers more 
 of the right one. On both sides, the pleura reaches the upper border 
 of the last rib, near its beginning, but the rib very soon runs away 
 from it, as may be inferred from PLATE IX. A case has been re- 
 ported in which a surgeon operating in the lumbar region to reach 
 the kidney, mistook the eleventh rib for the twelfth, and by carrying 
 the incision toward its lower border, opened the pleura. PLATE IX. 
 shows that at that level such an incision opposite the kidney would 
 certainly open the pleura on the right, and perhaps on the left. The 
 length of the twelfth rib is important in this connection, for the rib 
 is by no means always easy to recognize. Dr. Holl 1 examined sixty 
 skeletons of all ages to ascertain the absolute and relative length of 
 the twelfth rib. As there are two sides to each subject, and the ribs 
 are not necessarily symmetrical, this gives one hundred and twenty 
 observations. The longest twelfth rib measured 16.0 ctm. (giants and 
 children being omitted), and the shortest, 2.0 ctm. The twelfth was 
 three-fourths of the length of the eleventh in thirty-three cases ; one- 
 half in forty-four ; one-third in eighteen ; one-fourth in fifteen ; one- 
 sixth in three, and one-eighth in one. This shows how very variable 
 it may be. Holl points out as a fact of great surgical importance that 
 the pleura descends just as far as usual when the twelfth rib is want- 
 ing, or but slightly developed. 
 
 The pleura is attached rather loosely to the walls of the chest by 
 a layer of areolar tissue, which accounts for the slightness of the in- 
 jury it usually suffers in fractures of the ribs. 
 
 For all practical purposes, we may consider the diaphragm as a 
 circular muscle whose fibres converge to the central tendon. This, 
 as stated above, is firmly attached to the pericardium, and through 
 this, to the vertebral column at the top of the thorax, and less firmly 
 to the cervical fascia and to the sternum. The bearing of these points 
 on the mechanism of respiration deserves careful study. The tho- 
 racic cavity can be enlarged by the raising of the upper ribs and of 
 the sternum, which together with some slight rotation of the ribs, in- 
 
 1 Die Bedeutung der Zwolften Rippe bei der Nephrotomie. Archiv fur klinische Chi- 
 rurgie. Band xxv., 1880. 
 
Frozen Sections of a Child. 33 
 
 creases both the vertical and the transverse diameters. An important 
 part of the process, however, is the contraction of the diaphragm, by 
 which the tendinous centre is made tense, and the abdominal viscera 
 depressed. Now, for the muscle to act effectively, its lateral points of 
 origin must be fixed, and this is done by the muscles that pull the 
 lower ribs downward and backward. Such are the quadratus lum- 
 borum, the serratus posticus inferior, and many of the small lateral 
 bellies of the great erector spins. The ribs, therefore, may be pulled 
 both upward and downward in vigorous inspiration, or at least the 
 lower ones may be drawn rather backward and held fast. This 
 question has been confused by those who use the words " inspiratory " 
 as applied to a muscle as synonymous with "raising the ribs," which 
 involves, if the above view be correct, a serious error. Mechanical 
 toys, like Hamberger's bars are quite misleading. The vexed and 
 very complicated question of the action of the intercostals is much 
 simplified by this theory. If the movements of all the ribs are not free 
 and in the same direction, these muscles cannot have a common ef- 
 fect on all parts of the thorax. This is true whether applied to both 
 the external and internal intercostals, or to either set separately. In 
 point of fact the action of both is simply to draw the more movable 
 ribs toward the more fixed. Those in the upper part of the chest 
 pull upward, those in the lower downward, and the action of almost 
 any set of them must vary with circumstances. There is, however, 
 another point to be considered, namely, the effect of the inspiratory 
 movement on the great veins that lead to the heart. 1 The opening of 
 the cava inferior through the tendinous portion is made as large as 
 possible by the contraction of that muscle, and the suction power, both 
 of the inspiratory enlargement of the chest and of the relaxing auricle, 
 act very strongly on the contents of the vena cava and on the portal 
 circulation. Two large branches of the hepatic vein are seen in PLATE 
 VII. on their way to the cava, which they enter just below the dia- 
 phragm. A similar effect is, no doubt, produced on the great veins at 
 the root of the neck. 
 
 Leaving the liver and stomach for the next chapter, we will dis- 
 cuss the spleen. It reaches nearly, if not quite as high, as the stom- 
 ach, that is, somewhat below the level of the head of the ninth rib. 
 It extends to the lower half of the first lumbar. It is evident that the 
 
 1 Forbes on the Diaphragm. The American Journal of Medical Science, July, 1880. 
 
 5 
 
34 Frozen Sections of a Child. 
 
 upper part is nearer the spine than the lower. It is entirely under 
 cover of the ribs. Luschka describes it as following the ninth, tenth, 
 and eleventh ribs, a description that would apply very tolerably to 
 this case. The great peculiarity of the spleen in this instance is its 
 relation to the peritoneum. Usually it is entirely covered, except 
 near the hylus, with a prolongation from the lining of the great peri- 
 toneal cavity, though it is stated that at least in the young subject a 
 portion of the lower and posterior surface derives its covering from 
 the lesser cavity. Here, however, a large part of the organ is with- 
 out any serous covering. The anterior layer of the gastro-splenic 
 omentum may be seen in PLATE VIII., running backward from the 
 outer surface of the stomach to the inner one of the spleen, but the 
 posterior layer does not exist, because the fold of peritoneum, which 
 ought to be carried around the back of the spleen to form it, is seen 
 stopping short between that organ and the kidney. 
 
fy 
 
 ^ 
 

PLATE VIII. 
 
 THIS section, on an average 2 ctm. below the last, is unfortunately > 
 uneven from side to side. The left side is perhaps as much as 
 5 mm. below the right. The column is divided at the disc below the 
 eleventh dorsal. The ribs are not very unsymmetrical, but the carti- 
 lage of the seventh is divided at its lowest part on the left, while on 
 the right it passes below the section. We do not see the head of a 
 rib opposite the intervertebral cartilage, as the eleventh and twelfth 
 ribs arise from their respective vertebrae. The tenth usually arises 
 from the tenth vertebra and a part of the cartilage above it, without 
 reaching the ninth. 
 
 The liver fills a much larger part of the abdomen than in the 
 adult, though proportionally smaller than in the fcetus. The greatest 
 transverse diameter is shown in PLATE VII., but that is not so great 
 as is sometimes considered normal for the adult. The great increase 
 of size is due to the depth. It almost reaches the level of PLATE VI., 
 from which it is separated only by the diaphragm, and it extends 
 downward below PLATE X. to the third lumbar vertebra. The out- 
 line of the anterior edge can be readily deduced from the plates. It 
 rises gradually to PLATE IX., and then more rapidly. The liver of a 
 healthy adult lying on his back should not descend below the border 
 of the ribs, except in the region of the ensiform cartilage. It is evi- 
 dent that in this case the liver considerably exceeds these limits. 
 This is not the result of disease, but a characteristic of the age of 
 the child. 
 
 The liver is usually described as having an upper and a lower 
 surface, an anterior border, which is thin, and a posterior one, which 
 is thick, especially on the right. The lobe of Spigelius is marked off 
 on the under surface by the fissure of the vena cava on the right, the 
 transverse one in front, and that of the obliterated ductus venosus on 
 the left. How the inferior cava comes to be lying along the under sur- 
 
36 Frozen Sections of a Child. 
 
 face is not explained. His 1 has the merit of showing that this descrip- 
 tion applies to the liver removed from the body, drained of its blood, 
 and distorted by its own weight. When in situ the liver has not a 
 posterior border, but a posterior surface. The vena cava makes a deep 
 groove in the rear, as is seen in PLATES VII. and VIII. ; indeed, in 
 the former it is almost surrounded by the liver. The lobe of Spigelius 
 lies to the left of it, and is, at least, as much on the hind as on the 
 lower surface of the liver. The transverse fissure, which forms its an- 
 terior boundary, cuts through to the level of PLATE VIII., and shows 
 the outline of this lobe very clearly. The oesophagus often makes a 
 slight groove in the liver. To the left of this the posterior surface 
 passes into the posterior border. The impression from the right kid- 
 ney is also in part on the posterior surface, as is shown in PLATE IX. 
 The tissue of the liver is very yielding ; it resembles a sponge filled 
 with blood, and very probably can undergo slight temporary changes 
 of form by the pressure of neighboring parts. That long-continued 
 pressure will make permanent changes is well known. Hence it is 
 very likely that the liver, which in early fcetal life filled a great part of 
 the abdomen, is reduced to its proper shape and size by the pressure 
 of the growing organs around it. The right coronary ligament is 
 opposite the tenth rib. To understand its formation, remember that 
 a part of the back of the liver has no peritoneal covering. The serous 
 membrane of the top of the liver is reflected upward and forward 
 under the diaphragm ; that of the lower surface of the right lobe down- 
 ward over the posterior wall. These two folds approach one another 
 at the right side of the liver, and at last meet back to back, form- 
 ing the triangular ligament. The falciform ligament is seen in front, 
 running very obliquely to reach the umbilical fissure which appears in 
 PLATE IX. The aorta is about passing through the diaphragm at this 
 level. Immediately after this it gives off the cceliac axis, of which all 
 three branches are seen in this plate. The splenic is seen near the 
 front surface of the spleen, the coronary of the stomach between that 
 organ and the liver, and the hepatic in the transverse fissure. A 
 branch of the portal vein lies in the right division of this fissure. 
 Both the supra-renal capsules are shown, presenting, however, quite 
 different outlines. In front of .the left one lies a ganglion of the sym- 
 pathetic system. 
 
 1 Archiv fur Anatomic und Entwickelungsgeschichte. 1878. 
 
Frozen Sections of a Child. 37 
 
 The views of the stomach are very instructive. They confirm 
 entirely Luschka's statement that the fundus points upward, and that 
 the lesser curvature is essentially vertical. It is astonishing to find it 
 still described as the upper border of the stomach. The fundus 
 reaches nearly as high as the liver. In the axillary line it is opposite 
 the seventh rib. In PLATE VII. it is seen cut transversely. The next 
 view shows the stomach changing its position, running at first forward, 
 and then turning to the right beneath the liver. The lowest part of 
 the greater curvature is seen in PLATE X. This shows also precisely 
 how far it extends to the right. Certainly five-sixths of the stomach 
 are on the left of the median line, as Luschka states. The pylorus is 
 seen in PLATE IX., opposite the first lumbar vertebra. By comparing 
 this plate with the two preceding, the direction of the lesser curvature 
 can be made out. The pylorus is usually found between the ensiform 
 cartilage and the right costal arch. 1 
 
 Some important relations of the peritoneum can be studied in 
 PLATE VIII. The space behind the stomach, which extends down 
 into the great omentum, is a part of the lesser peritoneal cavity and 
 communicates with the general cavity by the foramen of Winslow. 
 Remembering that this foramen is bounded below by the duodenum, 
 in front by the portal vessels, behind by the vena cava, and above by 
 the lobe of Spigelius, we see that a line drawn directly forward in this 
 section, from the vena cava to the transverse fissure, would indicate 
 its position, and, indeed, be separated from it only by a thin layer of 
 liver. The < shaped peritoneal cavity, which we see to the left of 
 the lobe of Spigelius, also belongs to the cavity of the omentum. 
 Its anterior wall in this place is formed by the gastro-hepatic omen- 
 turn, a double layer of peritoneum running from the transverse fis- 
 sure to the lesser curvature. A considerable part of the spleen is 
 shown at this level without peritoneal covering. 
 
 1 If I remember rightly, the stomach contained frozen milk when the section was made. 
 It was very moderately distended. The fact that the lowest part of the stomach is contracted 
 and the upper dilated is easily understood when it is remembered that the body was frozen lying 
 on its back ; so that the contents of the stomach would naturally gravitate toward the fundus. 
 
v^ 
 
PLATE IX. 
 
 THIS section is, perhaps, on the average, 1.8 ctm. below the pre- 
 ceding, and is practically level. The cancellated tissue of the 
 first lumbar vertebra is just nicked at its highest point. The rela- 
 tions correspond remarkably well with those shown in one of Braune's 
 sections through the middle of the same vertebra, the chief difference 
 being that this plate shows more of the liver and stomach. The last 
 four ribs are shown on both sides, and each ninth rib is cut at its 
 junction with its cartilage. In Braune's plate the lowest part of the 
 seventh is shown on one side pretty much as it is shown in PLATE 
 VIII. From this we may infer that not only are the stomach and 
 liver proportionally larger in the child, but also that the lower part 
 of the front of the thorax does not descend so low as in the adult. 
 The lowest part of the pleura is seen on each side. The umbilical 
 fissure, containing the falciform ligament, cuts off the left lobe of the 
 liver. The gall-bladder is opened. It does not extend so far forward 
 as in the adult. The kidneys lie on each side of the spinal column. 
 The left one is divided near its middle, the right one above it. The 
 aorta, lying between the vertebral origins of the diaphragm, is seen 
 giving off the superior mesenteric artery. The portal vein is directly 
 before it, below the pancreas. This is formed by the junction of the 
 splenic and superior mesenteric veins. The inferior mesenteric is a 
 tributary of the former. The vena cava appears immense in this sec- 
 tion, which is due to the fact that the right renal vein is laid open at 
 its entrance into it, so that they are shown as one. Valves at or near 
 the mouth of each renal vein and those of the spermatic veins have 
 been alluded to, but the slight descriptions given of them do not 
 agree. Mr. Rivington, 1 who has carefully examined a small number 
 of cases, thinks more extended observations would be likely to estab- 
 lish the existence of valves at the orifices of both the right and left 
 spermatic veins with few exceptions. When no valves exist at the 
 
 1 Valves of the Renal Veins. Journal of Anatomy and Physiology. Vol. VI. 
 
40 Frozen Sections of a Child. 
 
 opening of the left spermatic vein, some are generally found near it 
 in the renal vein. He found several instances of valves at or neat: 
 the mouths of the renal veins and also of the semilunar fold at the 
 lower part of the orifice of the renal vein which had been described 
 before. 
 
 Perhaps the most important feature of this plate is the view of the 
 beginning and the end of the duodenum. A probe is passed through 
 the pylorus. The thickening of the muscular layer at this point is 
 very striking. The opening looks almost directly backward. The 
 inferior wall of the duodenum is seen in this plate, but the cavity of 
 the gut rises above this level as it passes between the gall-bladder 
 and the head of the pancreas. It then turns abruptly downward, and 
 we see it descending between the gall-bladder and the renal vein. 
 In PLATE X. it is seen, having again changed its direction, running 
 from right to left across the body of the second lumbar vertebra be- 
 hind the mesentery, in which branches of the superior mesenteric 
 artery are seen. It then rises and inclines forward to end in the fold 
 shown in PLATE IX. Thus we see both ends of the duodenum at 
 about the same level. They are both, to a certain extent, fixed 
 points ; the former being attached to the stomach, and the latter sus- 
 pended by muscular fibres coming from the cceliac axis and the cms 
 of the diaphragm. The remainder of the duodenum to wit, all but 
 the ends is pretty freely movable. It has been compared to a horse- 
 shoe, and to a ring not quite completed. 1 The plates show its peri- 
 toneal relations very fairly. In PLATE IX. we see its first part cov- 
 ered by peritoneum on the right from- the general cavity, on the left 
 from the lesser, both being prolonged from the front and the back of 
 the stomach respectively. In PLATE X. the peritoneum is seen cov- 
 ering the front of the transverse portion, excepting where it is behind 
 the mesentery. On the left, it begins to be surrounded again by the 
 peritoneum. In PLATE IX. the colon appears in a mass of fat between 
 the liver and spleen. Its apparently minute size and the absence of 
 all peritoneal attachment will be accounted for when it is known that 
 the very highest point of the colon is barely touched. A considerable 
 part of the pancreas appears in this plate, in front of the first lumbar 
 vertebra. The head lies against the duodenum, the tail in front of the 
 left kidney. The peritoneum passes over its anterior surface. 
 
 ' Braune : Archiv fur Anatomie und Entwickelungsgeschichte. 1877. 
 
.! 
 
 V 
 
 ^ 
 
 \ 
 
PLATE X. 
 
 r I ^HE slice above this section, as well as the remainder, are rather 
 JL thicker than those through the upper part of the body ; thus, 
 the level of this plate is nearly 2.3 ctm. below that of the preceding. 
 The second lumbar vertebrae is divided in its lower half. The carti- 
 lages of tVie eleventh and twelfth ribs are cut near their tips ; they are 
 now quite out of the thoracic region, and end between the abdominal 
 muscles. The cartilage of the tenth rib is missed on the right by a 
 hair's breadth. The lumbar region of the spine has a mean length in 
 the adult of 17.2 ctm., forming 29.84 per cent, of the movable portion 
 of the spine. The intervertebral disks represent 44.6 per cent, of it. 
 The diameter of the abdomen from before backward is less compared 
 with the breadth than in the last plate, probably on account of the 
 small piece of the liver that is found in this section. The lowest part 
 of the stomach lies in front, and on either side of it a piece of the 
 colon is seen. A piece of the colon appears by each kidney. The 
 transverse colon, as may be inferred from this plate, is a loop or fes- 
 toon attached at two points to the back of the abdomen, and hanging 
 both downward and forward. The relations of the peritoneum to the 
 colon are interesting, though more important in other parts of it than 
 in those shown in this plate. The parts of the ascending and descend- 
 ing colon lying by either kidney are but partially covered. The great 
 omentum is seen prolonged from the left of the stomach across a piece 
 of the transverse colon. Let it be remembered that the cavity of the 
 omentum is behind the stomach and above the transverse meso-colon, 
 and then is prolonged downward in a fold of peritoneum attached to 
 the stomach above and passing over the front of the colon, and in- 
 separably united to the upper anterior surface of the meso-colon, from 
 which it originally was distinct. The descending portion of the 
 omentum was necessarily drawn in a conventional manner, which 
 makes it appear thicker than it really is at this age. It may become 
 6 
 
42 Frozen Sections of a Child. 
 
 loaded with fat in the adult. The mesentery lies in front of the du- 
 odenum, just below the origin of the transverse meso-colon, and con- 
 tains the greater part of the ramifications of the superior mesenteric 
 artery in its folds. 
 
 The kidneys present, in this plate, pretty nearly the reverse of 
 their relative sizes, as shown in PLATE IX. The right one is here 
 divided at about its middle, and the left one below it. PLATE VIII. 
 shows the left kidney at the disk between the eleventh and twelfth 
 vertebrae, in an angle bounded by the stomach in front and the spleen 
 on the left. The diaphragm and pleura overlap it behind. The 
 left kidney is the higher, though PLATE VIII. unfortunately makes it 
 appear a little higher than it should, owing to the obliquity of the cut. 
 The right one, which is seen alone in PLATE XL, is clearly the lower. 
 The left kidney is said to reach to the upper border of the eleventh 
 rib, and the right half a rib's breadth lower. It is very possible that 
 the difference between the two is more marked in this case, and that 
 the left one is a trifle higher ; but this account is not far wrong. 
 About half of the right kidney appears below the ribs, and rather 
 less of the left. The diaphragm, as already stated, covers the back 
 of their upper ends, and lower down they rest against the quadratus 
 lumborum behind and the psoas on their inner side. The peritoneum 
 rests against them to a varying extent, but normally never surrounds 
 them. A kidney may be movable from either one of two causes : ist, 
 it may have a peritoneal covering and a true mesentery ; 2d, and, 
 more commonly, the areolar tissue that surrounds it may become less 
 firm than before, especially by the loss of fat, and thus leave the kid- 
 ney without support. 
 
 The three muscular layers bounding the sides of the abdomen 
 present some features that call for notice. It is interesting to see 
 that the external and internal oblique run in the same direction, and 
 are in the same planes as the external and internal intercostals, respec- 
 tively, and that the triangularis sterni appears to be a continuation of 
 the transversalis. As to the action of these muscles and the purpose 
 of their arrangement, it is evident that they protect the contents of 
 the abdomen more effectually than if their fibres all ran in one direc- 
 tion. There is, I think, no evidence that they can contract indepen- 
 dently, and their close connection makes it improbable. They are 
 essentially compressors of the abdomen ; they help to extrude its ex- 
 cretions, and they are sometimes antagonists of the diaphragm. They 
 
Frozen Sections of a Child. 43 
 
 assist to give it a firm support for contraction by steadying the tho- 
 rax. Carried further, their action is to flex the body forward, and, it 
 may be, when one side acts alone, to twist it. 
 
 The posterior border of the external oblique does not pass off 
 into any fascia, but is a distinct line running from the last rib to the 
 crest of the ilium, forming the front of a triangle, the base of which is 
 a small portion of the crest, the posterior border being formed by the 
 front edpfe of the latissimus dorsi. This is the triangle of Petit. The 
 
 o o 
 
 latissimus may reach the external oblique, or even overlap it, as, I 
 think, is the case on the left side of PLATE X. In either case, of 
 course the triangle does not exist ; it is usually to be found in adults, 
 and not in infants. Lesshaft 1 found it eighty-four times in one hun- 
 dred and eight bodies of adults, and only nine times in thirty-five 
 bodies of new-born children and foetuses. The floor of this triangle 
 is formed by the posterior fibres of the internal oblique. It is a weak 
 point in the abdominal wall. The muscular belly of the great erector 
 spinae is seen in this plate, but more developed in the following. It 
 is a very powerful muscle, and with the gluteus maximus is the most 
 important in maintaining the erect position. The nomenclature of 
 English anatomists is very clumsy that of Henle very simple and 
 explanatory instead of confusing. In English we have it divided into 
 seven pieces. The innermost is the spinalis dorsi, which runs be- 
 tween the spines of the upper lumbar and lower dorsal vertebrae and 
 those of the upper dorsal region. Then comes the longissimus dorsi, 
 prolonged by the transversalis cervicis to the neck, and that, in turn, 
 by the trachelo-mastoid to the head. Outside of this column lies the 
 ilio-costalis, its accessory muscle, and finally the cervicalis ascendens, 
 ending at the transverse processes of the neck. Henle very properly 
 omits the spinalis dorsi, treating it as a separate muscle. There 
 then remains the great muscular mass derived from the ilium, the 
 lumbar fascia, and sacrum, which divides into two main columns, com- 
 posed the inner of the longissimus dorsi, cervicis, and capitis ; the 
 outer of the ilio-costalis lumborum, dorsi, and cervicis, respectively. 
 
 1 Die Lumbalgegend in anatomisch-chirurgischer Hinsicht. Archiv fur Anatomic, Phy- 
 siologic und wissenschaftliche Medicin. (Reichert and Du Bois Reymond.) 1870. 
 
* f "* > "V* " r 
 
 . * . * J * * - 1 
 
 *** "> * ,*c J***S * * <,*" "* 
 
PLATE XI. 
 
 THIS section is about 2.4 ctm. below the last. It passes through 
 the intervertebral disk between the third and fourth lumbar 
 vertebrae, showing the spine and arch of the former, embraced by the 
 articular processes of the latter. The breadth of the vertebral column 
 is apparent. The spinal cord has come to an end in the thickness of 
 the slice above, probably near the top of the third lumbar. At birth 
 it is said to approach the fourth lumbar, but owing to the more rapid 
 growth of the spinal column, it subsequently is not found so low. In 
 man it ends at about the lower border of the first, and in woman, 
 perhaps half way down the second. Nevertheless, according to 
 Ravenel, 1 the female cord is relatively shorter than the male. In this 
 subject the cord is still relatively long. In the adult the origins of the 
 nerves of the lumbar plexus are opposite the space from the eleventh 
 to the twelfth dorsal spine, or a little lower, and those of the sacral 
 plexus extend from the latter point to the first lumbar spine. They 
 are, of course, lower here, but they cannot easily be placed. 
 
 The umbilicus is rather below the level of this cut, opposite the 
 fourth lumbar. Holden places it opposite the third lumbar, and 
 Luschka opposite the lower edge of that vertebra. If I may differ 
 from such authorities, I should say that it is more frequently below 
 than above the disk between the third and fourth lumbar vertebrae, 
 and near the level of the highest point of the crest of the ilium. I do 
 not think that in this instance it is far from the adult position, though 
 still rather lower. 
 
 The great omentum lies in front of the intestines. Two pieces 
 of the mesentery are seen, one of which runs transversely, and the 
 other forward toward the right rectus. In the right anterior part of 
 the abdomen there is an appearance somewhat resembling a diver- 
 ticulum, such as is sometimes found in the lower part of the ilium. It 
 is not one, however, but a true invagination of the intestine. There 
 
 Zeitschrift fur Anatomic and Entwickelungsgeschichte. Band II. 
 
46 Frozen Sections of a Child. 
 
 is no sign of inflammation around it. It is probable that small invagi- 
 nations occur not rarely in children, and reduce themselves without 
 giving rise to symptoms. 
 
 The caecum is seen in this plate lying on the right side of the ab- 
 domen. More than one-half of it is below the surface of this section, 
 so that we may with sufficient accuracy say that it is on a level with 
 the umbilicus. The ilium lies on the left of the caecum as it descends 
 to open into it lower down. The vermiform appendix, which arises 
 from the rear of the caecum at a still lower point, appears behind it. 
 It pursues a twisted course, in the main, upward and inward. To un- 
 derstand this position of the caecum, we must remember that in the 
 early part of fcetal life the caecum, which is a little diverticulum of 
 the intestine, lies below the liver near the median line. The future 
 large intestine runs from this point to the left, and then downward. 
 Gradually, however, the caecum moves to the right above the mesen- 
 tery, thus forming the transverse colon. It then descends along the 
 right side of the abdomen, forming the ascending colon. According to 
 Dr. Allen Thomson, 1 the parts are in the same positions as in the adult 
 in the fourth or fifth month of fcetal life. Kolliker 2 states that they 
 descend toward the iliac fossa in the latter half of fcetal life. It is evi- 
 dent that in this child the caecum has made very little progress in its 
 descent from the right hypochondrium. My observations lead me to 
 believe that the wanderings of the caecum are not completed as soon 
 as these authorities state. I doubt very much if, as a rule, it has 
 reached its permanent position at birth, and think that not very rarely 
 it does not reach it for a year or two afterward. 
 
 The ascending colon, what there is of it, runs upward in front of 
 the right kidney, in the angle between it and the lowest part of the 
 liver, as is shown in PLATE X. It rises a little above this level, but 
 soon turns down to reappear in the same plate as the transverse 
 colon, which is traced to the side of the stomach. It reappears on 
 the left of that organ, and rises higher than on the right. Its highest 
 point is just opened in PLATE IX. beside the beginning of the cartilage 
 of the ninth rib. The descending colon is seen in Plate X. outside of 
 the kidney. It follows the surface of the organ, so that below the 
 kidney in PLATE XI. we see it further in, just opposite the border of 
 the erector spinae. In PLATE XII. it is making its way forward, lying 
 
 1 Quain's Anatomy. Eighth edition. Vol.11. s Entwickelungsgeschichte. 
 
Frozen Sections of a Child. 4; 
 
 in the angle between the psoas and iliacus. In the next plate it has 
 reached the abdominal walls, and a little later begins to form the 
 sigmoid flexure, which we will leave for the present. Two points of 
 comparison with the adult arrangement must be mentioned. The 
 right colon of the adult passes in front of the right kidney, as is the 
 case with its rudiment here. 1 The left colon on the other hand, lies 
 on the outer side of the left kidney. The transverse colon in the 
 adult not uncommonly hangs down in front as low as the umbilicus. 
 Both the ascending and descending colon are but partly covered by 
 peritoneum at the level of PLATE- X. The descending one, however, 
 is more covered in the next plate, and has a true mesentery in the 
 iliac fossa. The relation of the peritoneum to the colon, especially 
 on the left, is of much surgical importance. The extent to which the 
 gut is covered varies extremely, and at all ages. Lesshaft found that 
 on the average the left colon had a mesentery, usually a very short 
 one, once in six subjects. 
 
 The lumbar fascia deserves notice. The superficial layer is a 
 very strong diamond-shaped aponeurosis, extending high up in the 
 dorsal region, down toward the coccyx, and laterally on to the ilia. 
 The latissimus dorsi arises from it above, as does also the serratus 
 inferior, and the gluteus maximus springs from it below. The erec- 
 tor spinse which it bridges over has a part of its origin from the deep 
 surface of this fascia. In short, the muscles that straighten the body, 
 by drawing both the upper and under halves backward, spring from 
 it. This arrangement shows the necessity of the thickness of the 
 anterior portion of the capsule of the hip-joint. At the outer margin 
 of the erector spinae the fascia above described is joined by the mid- 
 dle layer of the lumbar fascia, which runs to the transverse processes 
 of the lumbar vertebrae. This is continuous with the transversalis 
 muscle, and some fibres of the internal oblique arise from its posterior 
 surface. In front of this fascia lies the quadratus lumborum, which 
 extends beyond the outer edge of the erector. Covering the anterior 
 surface of the quadratus is the inner layer of the lumbar fascia, ex- 
 tending from the roots of the transverse processes outward to join 
 also the transversalis muscle. Below it is attached to the crest of 
 the ilium, and it ends above as the ligamenta arcuata. The superfi- 
 cial layer of the lumbar fascia, which is very dense is shown in PLATE 
 XL, turning round the outer borders of the erectores. 
 
 1 Lesshaft, loc. cit. This rule does not seem to be quite without exceptions. 
 
,') 
 
 "X 
 
PLATE XII. 
 
 THIS section, about 2.4 ctm. below the last, is not quite even, the 
 right side being the higher. Though the difference is slight, 
 it is sufficient to occasion considerable discrepancy between the lateral 
 halves which otherwise would be nearly symmetrical. The right 
 ilium, of course, seems not only shorter, but more cartilaginous than 
 the other. The fifth lumbar vertebra shows an asymmetry that is really 
 only apparent, for on the left it is struck at its prominent lower bor- 
 der, and on the right in the concavity which its surface presents. The 
 articular process of the sacrum appears on the left, but not on the 
 right. The fifth lumbar is shown enclosed by the ilia, which project 
 above it and behind all of it except the spinous process. The ilio- 
 lumbar ligament, running from the transverse process of the last lum- 
 bar to the crest of the ilium, is above this section, but strong bands 
 of fibres, running more or less obliquely between different points of 
 the vertebral column and the ilium, are seen on both sides. It is well 
 to remember that the spine of the fourth lumbar vertebra is on a level 
 with the highest point of the crest of the ilium. 
 
 Having reached the lower end of the movable portion of the 
 spinal column something may be said of its curves, and first of those 
 in the adult. There is no absolute standard ; all people do not have 
 the same curve. Apart from the peculiarities of the figure of each 
 individual, the curve is modified by the profession, the age, various 
 diseases, by fatigue, and by position. Mr. Wood 1 gives a rule which, 
 though it is not confirmed by my observations, is, no doubt, approxi- 
 mately correct, and is certainly simple : it is that a line from the cen- 
 tre of the body of the axis to that of the last lumbar vertebra at its 
 articulation with the sacrum passes through the body of the first dor- 
 
 1 Topographical Relations of Arch of Aorta, etc. Journal of Anatomy and Physiology. 
 Vol. III. 
 
 7 
 
50 Frozen Sections of a Child. 
 
 sal and second lumbar. He adds that it " would indicate the line of 
 gravity of the head and trunk in a perfectly upright and balanced 
 position, traversing the pelvis midway between the cotylo-femoral 
 joints and falling between the bases of support." It should be stated 
 that these remarks of Mr. Wood apply especially to the young adult 
 male. Henle's rule that the middle of a line from the top of the atlas 
 to the end of the coccyx is opposite the eleventh dorsal, that the first 
 quarter ends opposite the lower border of the third dorsal, and the 
 third quarter opposite the lower edge of the fourth lumbar, has seemed 
 to me remarkably accurate. At birth the spinal column is very nearly 
 straight ; indeed, the line of the spinous processes may be perfectly 
 so, but the bodies of the vertebrae show a curve in the cervical and 
 dorsal regions. 1 According to Ballandin 2 the normal curve of the 
 neck does not appear till the third month after birth. It soon be- 
 comes more stable, as does also the dorsal one. The lumbar curve 
 does not appear till the child begins to walk, and it is stated that it 
 can be obliterated by traction on the detached spine till the twentieth 
 year. Ballandin's views on the production of the lumbar curve are 
 interesting and plausible, and agree well with what was said in the 
 last chapter concerning the powerful muscles of the back that main- 
 tain the upright position and the strength of the front part of the cap- 
 sule of the hip. Ballandin states that if a very young child be laid on 
 its back, with the lumbar and dorsal spinous processes resting on the 
 table, the legs naturally assume the position of outward rotation, the 
 knees usually being somewhat bent. If the knees are brought to- 
 gether, they at once spring up farther from the table ; but if they be 
 pressed down and made to touch it, the abdomen becomes prominent 
 and the spinal column bends forward in the lumbar region. The 
 same thing occurs after the removal of the viscera, and can be shown 
 to depend on the shortness of the ilio-femoral ligaments. As the child 
 learns to stand and walk, and the great erector muscles are raising the 
 body, they are constantly resisted by this ligament (assisted probably 
 by the iliacus and psoas), and thus the obliquity of the pelvis is in- 
 creased and the lumbar region of the spine pulled forward. 
 
 Returning to this plate we find little worthy of notice in the ab- 
 dominal viscera. The colon is seen between the left iliacus and psoas, 
 
 1 Bouland : Robin's Journal de FAnatomie et de la Physiologic. 1872. 
 ' Virchow's Archives. Vol. LVII. 
 
Frozen Sections of a Child. 51 
 
 the omentum is still in front, and the remainder of the space is filled 
 by folds of small intestine, which are distended on the left and con- 
 tracted on the right. The psoas makes a bold projection on either 
 side of the vertebra. Nerves of the lumbar plexus are seen within it. 
 A considerable amount of fat lies between the psoas and iliacus be- 
 hind the peritoneum. The aorta has divided in the thickness of the 
 slice above this plate, presumably at about the normal position oppo- 
 site the middle of the fourth lumbar vertebra. It is much more likely 
 to divide below than above this point. The common iliac artery and 
 vein are seen on the right, while on the left, at a somewhat lower 
 level, the external and internal iliac arteries lie, just after their origin, 
 in front of the common iliac vein, which is running very obliquely at 
 this point. The iliac arteries usually divide near the lower border 
 of the last lumbar vertebra. The right one is usually the longer. 
 Their relations to veins differ materially. At their lower ends each 
 has the vein at its inner side, but the left vein inclines to the right, as 
 does also the right one, which gets behind its artery, and the two 
 unite to form the vena cava behind the right iliac at a point below the 
 bifurcation of the aorta. 
 
 Nothing has been said of the ureters, which, indeed, call for little 
 comment till they reach the bladder. They descend along the psoas 
 behind the peritoneum. In this plate they are still on the outside of 
 the iliac vessels, which they usually cross near the division of the 
 common iliacs. In PLATE XIII. they pass near the outer angles of 
 the promontory of the sacrum. It is not uncommon for the ureter to 
 be double at its origin, but the two roots almost always unite before 
 opening into the bladder. 
 
PLATE XIII. 
 
 0* 
 
PLATE XIII. 
 
 THIS is an interesting but, at first, a very confusing section. It is 
 nearly 2.5 ctm. below the last, and rather higher on the right 
 than on the left. The very curious view of the sacrum suggests that 
 the cut slants backward, but it does so, at most, to a very slight ex- 
 tent. The anterior superior spinous processes of the ilia are struck 
 pretty evenly on both sides. The articular surface of the ilium is 
 separated from the expanded portion that forms the wall of the false 
 pelvis by a well-marked angle which represents the beginning of the 
 ilio-pectineal line at the edge of the promontory of the sacrum. On 
 account of the relations of the great sacral nerves to the vertebrae it 
 will be convenient to consider both together. The fifth lumbar nerve 
 is seen in PLATE XII. leaving the spinal canal ; it is seen again in this 
 plate, close by the promontory, as the lumbo-sacral cord, a name it 
 assumes after it is joined by a branch from the fourth lumbar, which 
 probably has occurred before it has reached this level. The first 
 sacral nerve appears just as it leaves the anterior sacral foramen. 
 The bodies and the lateral masses of the second and third sacral verte- 
 brae are seen farther back, cut very obliquely. The second sacral nerve 
 lies in the foramen between them. The arch of the third vertebra is 
 very accurately hit. The third sacral nerve, much smaller than the 
 preceding ones, lies in the canal, which it is just about to leave. The 
 sacral plexus, be it remembered, is formed by the lumbo-sacral cord, 
 the first three sacral nerves, and a branch of the fourth. It is a broad 
 nervous band, reaching toward the lower part of the great sacro-sciatic 
 foramen, which its direct continuation, the great sciatic nerve, leaves 
 below the pyriformis. The view of the process of ossification is a very 
 instructive one. The inclination of the pelvis must be very consider- 
 able to account for this view of the sacrum. To place the pelvis in 
 its proper position, the normal conjugata of Hermann Meyer should 
 form an angle of 30 with the horizon. This conjugata is a line run- 
 
54 Frozen Sections of a Child. 
 
 ning from the top of the symphysis to a transverse line across the 
 body of the third sacral vertebra. The anterior superior spines of 
 the ilia should be in the same vertical plane as the spines of the pubes, 
 and perhaps even a little in front of it. Very different views are ex- 
 pressed as to the difference in the curve of the male and female 
 sacrum. I agree with Ward that the male sacrum is the more curved, 
 and that the curve is more regular. The female sacrum is more dis- 
 tinctly divided into two parts, the upper of which is smooth and the 
 lower curved, by the line just mentioned, which crosses the third ver- 
 tebra. This line, I believe, was first described by Hermann Meyer. 
 It is not rare to find the sacrum composed of six vertebrae. Some- 
 times it seems as if there were an extra piece, intermediate in charac- 
 ter and position, between the lumbar and sacral vertebrae, or the 
 number of the latter is evidently increased. Bacarisse 1 gives a rule for 
 determining whether a mutilated sacrum is one of five or six pieces. If 
 a line connecting the lower ends of the auricular surfaces pass above 
 the middle of the third vertebra, there are five pieces ; if below it, 
 six. The sacro-iliac synchondrosis is one of the strongest in the 
 body, but great additional strength is gained by the very strong liga- 
 ments passing from the sides of the sacrum and the back of the ilia, 
 so as to oppose the separation of the latter by the weight of the body 
 on the sacrum. The psoas and iliacus lying on the inner side of the 
 ilium encroach a good deal on the abdominal cavity. The tendon of 
 the psoas, at first inside the muscle, has now reached its outer border. 
 It receives fibres from the iliacus as well as from the psoas. The vis- 
 cera that are shown in this plate are, for the most part, either in or 
 above the cavity of the true pelvis. The descending colon, and some 
 folds of the small intestine, occupy the iliac fossae, and the anterior 
 wall of the abdomen is distended so as to project in front of the 
 pubes. Most of the remaining cavity is occupied by the sigmoid flexure 
 of the colon. The point where the descending colon ends and the 
 sigmoid flexure begins is not a very definitely placed one. In this 
 instance it is in the thickness of the slice below PLATE XIII. We see 
 the descending colon cut transversely. It passes to the right, turns 
 suddenly, and reappears behind the left rectus as the sigmoid. 
 Luschka places the beginning opposite the highest point of the crest 
 of the ilium, where the colon begins to be surrounded by peritoneum. 
 
 1 Inaugural Thesis. Paris. 1873. 
 
Frozen Sections of a Child. 55 
 
 It must be remembered that the whole descending colon may be so 
 covered, and there seems no reason for having the change of name 
 precede the change of direction. The sigmoid flexure in this case 
 forms a very respectable " S/' ending opposite the left sacro-iliac syn- 
 chondrosis, where the rectum begins. This flexure is attached to a 
 pretty long mesentery that allows it to move very freely. Its posi- 
 tion varies not only with the degree of its distention, but with that 
 also of the bladder and of the other folds of intestine. It may be 
 found in the right iliac fossa. In new-born children it very frequently 
 extends into the right inguinal region ; indeed, it is always there at 
 that age according to some authorities. 
 
 The ovaries are seen in this plate occupying very different posi- 
 tions from those they assume later. The right one is situated at the 
 margin of the true pelvis opposite the outer part of the promontory. 
 The left one is much farther forward, opposite the external iliac ves- 
 sels and entirely above the true pelvis, for this section strikes its 
 lower end. They are both placed with the end nearest the uterus 
 below, and with their flat surfaces looking sideways. They are cov- 
 ered by a fold of peritoneum. The ovaries, in fact, are descending 
 into the pelvis in a manner perfectly analogous to the descent of the 
 testes, only in a different direction. In the adult the ovaries are in 
 the true pelvis. It is very doubtful if they are always in the same 
 position. 
 
 The right external iliac artery appears much larger than the left, 
 which is probably due to the injection having been made from the 
 right femoral. The branches of the internal iliac vessels are much 
 behind them, making their way downward to the back of the pelvis. 
 The gluteal muscles are well shown, but require no special comment. 
 
$** 
 
 $>* 
 
PLATE XIV. 
 
 ^HE plane of this section is about 2.2 ctm. below that of the one 
 JL above. It passes 7 mm. above the symphysis of the pubis and 
 strikes the last piece of the sacrum. It is higher on the right than on 
 the left, but about level from before backward. Hence it is evident 
 that, in this case at least, the pelvis has reached its full inclination. 
 One is struck by the length of the antero-posterior diameter compared 
 with the transverse one ; but sections by Braune, Pirogoff, and Rudin- 
 ger show very nearly the same proportions in similar sections of the 
 adult pelvis. The prominence of the front of the abdomen, though 
 caused in part by the distended bladder, is due even more to the ac- 
 cumulation of subcutaneous fat above the pubes. At least half the 
 cavity is filled by the bladder, which was moderately distended with 
 urine. The cut divided it very nearly evenly. It is not pointed above, 
 as in infancy, but is irregularly globular and somewhat compressed 
 from before backward, which often is the case with the female bladder, 
 as is also, according to Luschka, the lateral asymmetry which is seen 
 in this instance. The lightly shaded part of the bladder shows the 
 place at which it bulges forward over the pubes. The summit of the 
 bladder is at the anterior border, where it extends upward between 
 the intestines and the abdominal wall. The posterior wall of the 
 bladder is thicker than the front one. The lowest point is at the 
 opening of the urethra, which is very sudden, if the expression is 
 allowable. There is the merest trace of a funnel-like narrowing, con- 
 stituting the so-called neck of the bladder. This, if it exist at all, is, at 
 all events, much less developed in the female than in the male. Straws 
 have been passed through the terminations of the ureters, which are 
 not themselves visible, as they open in the posterior wall of the blad- 
 der. The trigonum vesicce is a triangle formed by the openings of the 
 ureters and the urethra, the mucous membrane covering it being 
 smooth instead of in folds, as elsewhere. The wall below it is thickened 
 
58 Frozen Sections of a Child 
 
 by muscular fibres from the ureters, and a band running between their 
 orifices may cause a ridge in the bladder. Accounts of the position 
 of the trigonum do not agree. It is usually described as being at the 
 lowest part of the bladder, its posterior angles being somewhat raised. 
 Richet, however, states that the lowest part of the bladder is the 
 " bas fond" situated behind the trigonum. The openings of the ure- 
 ters in this case, however, are distinctly in the posterior wall. In an- 
 other girl, a little larger than this one, examined also by frozen sections, 
 they have very nearly the same position. In a boy of about the same 
 age, examined by opening the abdomen, the bladder was found nearly 
 empty, and the trigonum was in the lower wall, though the ends of the 
 ureters were higher than the urethra. There was a pouch formed by 
 the posterior wall behind the ridge, at the base of the triangle. It 
 seemed as if distention of the bladder would have raised the orifices 
 of the ureters. In Braune's sagittal section of a young male (twenty- 
 one years), they are in the posterior wall. It is probable that this is 
 their normal position in youth, and that, with advancing years, they 
 gradually sink lower, especially in the male, in whom the base of the 
 bladder is larger, and in whom the bladder is with more difficulty com- 
 pletely emptied from various causes, and in whom, chiefly on account 
 o the enlarging prostate, a depression or pouch behind the trigonum 
 is very frequently developed in the latter part of life. In the female, 
 this does not'occur. The peritoneum covering the bladder approaches 
 the plane of this section very closely at the anterior angles of the or- 
 gan, and behind it, where it is reflected over the uterus. In the median 
 line it does not come within 1.5 ctm. of the pubes. 
 
 This plate shows the lowest part of the body of the uterus. It is 
 not over two centimeters in length, measured as well as circumstances 
 permit along the posterior surface. It is less expanded at the upper 
 portion than in the adult. It inclines forward, resting against the back 
 of the bladder. The broad ligaments are seen on the under surface 
 of the slice above, running to the sides of the pelvis. The Fallopian 
 tubes run much more upward than in the adult, so that the ovaries 
 are seen in the preceding section. The folds of the broad ligament 
 contain, even at this age, many veins which later form a series of very 
 rich plexuses, which communicate both with the system of the iliac 
 veins, and also by the plexus pampiniformis and ovarian veins, with 
 the vena cava on the right and the renal vein on the left. These veins 
 may become largely dilated and varicose, forming a true varicocele in 
 
Frozen Sections of a Child. 59 
 
 the female. 1 The diagnosis cannot be made with certainty, but it is 
 very probable that this state would account for some of the obscure 
 pains felt in the left side only at the menstrual period. The rectum is 
 described elsewhere. Suffice it, therefore, to say that it is struck just 
 as it is completing a curve with its convexity to the right. Below the 
 fold, seen on the left, it expands to its greatest dimensions. This plate 
 shows the lowest part of the peritoneal pouch between it and the uterus, 
 which extends here as in the adult, behind the upper part of the vagina. 
 The distance of this from the anus is in this subject approximatively 
 2.5 ctm. According to Tillaux, in the adult male this distance is 5 ctm. 
 with an empty bladder and 6 ctm. for a full one. There may be a 
 variation, however, of 2 ctm. It is well known that when the bladder 
 is distended, a greater extent of it lies above the symphysis uncovered 
 by peritoneum. Dr. Garson 2 has shown that a distended rectum ma- 
 terially changes the relations both of the bladder and of the perito- 
 neum. His observations apply only to the male. He has shown that 
 by distending the rectum the bladder may be pushed bodily upward, 
 carrying the peritoneum farther from the symphysis, and raising it also 
 between the bladder and rectum. This displacement of the bladder 
 is due to stretching of the urethra, chiefly in the prostatic and some- 
 what in the membranous portion. 
 
 The greater and the lesser sacro-sciatic ligaments are seen most 
 distinctly on the right side. The latter lies inside of the former. With 
 the aid of the muscles they supply the deficiency in the walls of the 
 pelvis caused by the sciatic notch. The obturator internus is seen in- 
 side the pelvis, in the chamber formed by the bone and the obturator 
 fascia. A mass of fat occupies the ischio-rectal fossa between this and 
 the pelvic fascia which passes to the sides of the bladder, vagina, and 
 rectum. The left ischium is divided just at the spine, to which the 
 lesser ligament separating the two foramina is attached. The pudic 
 artery and nerve (the latter drawn rather large) are seen as they turn 
 round it. The glutei muscles are shown most clearly on the right. On 
 
 1 Some years ago, while injecting the system of the vena cava inferior from the common 
 iliac vein in a woman of at least middle age, I was surprised to see a very rich plexus of veins 
 appear in the left broad ligament and send a branch across the uterus. I found that this had 
 occurred by the passage of the injection from the left renal vein downward through the ova- 
 rian vein, which was as large as my little ringer. Vide Boston Medical and Surgical Journal, 
 Vol. 96. I subsequently found that this condition had been described in Richet's Anatomic 
 Medico-Chirurgicale. 
 
 * Edinburgh Medical Journal, October, 1878. 
 
60 Frozen Sections of a Child. 
 
 the left the top of the great trochanter appears. Its position shows 
 that the leg had rolled outward as the body lay on its back to be frozen. 
 The pyriformis, in two parts, is seen on the right. The great sciatic 
 nerve, which leaves the pelvis below it, appears in front of it. On the 
 left, where the plane is lower, this nerve has already made its way out- 
 ward, so as to lie behind the ischium. The lower branch of the great 
 or superior gluteal nerve is seen on both sides. The main trunk leaves 
 the pelvis above the pyriformis ; it then divides into two branches, of 
 which the lower may be seen more distinctly on the right side tending 
 toward the space between the gluteus medius and minimus. 
 
 The right hip-joint is opened so high up that but a very small 
 piece is taken from the head of the femur. Curiously enough, this 
 plate shows the three centres of ossification of the acetabulum ; that 
 of the ilium, which is the highest on the right, those of the pubes and 
 ischium on the left. The socket is not thoroughly solidified till the 
 seventeenth or eighteenth year. 
 

PLATE XV. 
 
 THIS section is about 2.2 ctm. below the last. It passes just be- 
 low the symphysis in front, and misses by a very little the tip 
 of the coccyx. These two points, therefore, are about on a level, if the 
 section is straight. There is, however, a suspicion that it may slant a 
 little backward. The tuberosities of the ischia with the pieces of the 
 pubes map out the lateral outlines of the pelvis, which appears triangu- 
 lar. If the section had been a little higher, so as to strike the tip of 
 the coccyx and the great sacro-sciatic ligament, it would have been 
 irregularly diamond-shaped. As it is, we see the obturator internus on 
 either side, in its case formed by the obturator membrane and the ob- 
 turator fascia ; and in the middle the urethra, vagina, and rectum, en- 
 closed by muscle which appears to be the lower part of the levator ani. 
 On either side of this is the fat of the ischio-rectal fossa, which runs 
 up between the levator and the obturator fascia, and is continuous 
 below with the fat of the thighs and buttocks. The coccygeus, which 
 runs from the spine of the ischium to the side of the coccyx, is in the 
 same plane as the levator ani, and what in the male is called the leva- 
 tor prostatse, and in the female runs to the sides of the vagina, is 
 really a part of the same. 
 
 We will now follow the rectum from its beginning, opposite the 
 left sacro-iliac synchondrosis, which appears in PLATE XIII. It then 
 sweeps downward, backward, and to the right, frequently, at least, 
 crossing the middle, and then describing another curve with its con- 
 vexity to the right, resumes its median position. PLATE XIV. shows 
 the last mentioned curve. On the left is seen a sharp fold formed by 
 the bowel which falls on the line of the section, below it the rectum 
 expands into a pouch opposite the last piece of the sacrum. The 
 rectum then runs forward and at last turns distinctly downward and 
 backward. This last curve exists in both sexes, and it is very im- 
 portant that it should not be forgotten when introducing instruments. 
 
62 Frozen Sections of a Child. 
 
 PLATE XV. shows the rectum at the beginning of the last curve and 
 below the expansion which it presented at the level of the preceding 
 plate. The folds of the mucous membrane of the rectum are mostly 
 vertical near the anus, this plate shows a well-marked anterior one ; 
 higher up they are transverse or oblique. The external sphincter 
 deserves its name, not only because it is below the internal, but be- 
 cause it surrounds it also. The fibres of the levator ani reach the 
 gut at the upper border of the external sphincter and mingle with 
 those of that muscle. Some 8 ctm. above the anus, there is very 
 commonly a thickening of the circular muscular fibres, called the third 
 sphincter. It is of little consequence and does not deserve the atten- 
 tion it has received. The mechanism of defecation is probably pretty 
 much as follows : The faeces accumulate in the sigmoid flexure, only 
 a small part descending into the rectum between operations, except 
 in cases of habitual constipation. When the mass passes into the 
 rectum in sufficient quantity, the need of an evacuation is felt, but the 
 process is started by the voluntary muscles, such as the diaphragm 
 and those of the abdomen which compress the abdominal contents. 
 This compression is increased by the contraction of the levator ani, 
 which at the same time tends to pull open the anus. The sphincters 
 yield before the pressure. Just how great a share of the work is 
 done by the muscles of the intestine proper can hardly be ascertained. 
 It is probable, however, that their assistance is necessary to com- 
 pletely empty the rectum. Doubtless sometimes they play the chief 
 part, and sometimes a very subordinate one. The upper part of the 
 rectum has a true mesentery, which permits moderate displacement. 
 It has been demonstrated that the whole hand can be introduced into 
 the rectum, and also that it had much better not be, unless the infor- 
 mation to be gained is of sufficient value to justify risking the patient's 
 life to obtain it. A wedge-shaped space between the lower parts of 
 the rectum and vagina, which bend respectively backward and for- 
 ward, is filled in part by the sphincter muscles and the remainder by 
 areolar tissue. This is the perinseum. The urethra is seen just in 
 front of the vagina. 
 
 The right femur is struck at the great trochanter. The lowest 
 part of the cavity of the joint is opened on that side, but on the left the 
 cut passes lower, a little above the trochanter minor. The psoas and 
 iliacus, now united, are seen on both sides, on the left, just above 
 their insertion. They lie in front of the hip-joint, and send some 
 
Frozen Sections of a Child, 63 
 
 fibres to the capsule, which is thus drawn out of the way by the same 
 muscle that flexes the thigh. A bursa is placed on the anterior sur- 
 face of the capsule, which sometimes opens into the joint. Pus from 
 a psoas abscess can in this way enter its cavity. The views of the 
 muscles are very nearly the same on both sides, the chief difference 
 being- that much more of the vastus externus is seen on the left. The 
 gluteus maximus and the tensor vaginae femoris are seen inserted into 
 the fascia lata, a part of which passes uninterruptedly from the crest 
 of the ilium to the tibia. The rectus lies beside the tensor, and the 
 sartorius is seen in front. On the left leg the last overlaps the femoral 
 vessels, which lie on the pectineus, the adductor longus being between 
 the latter and the median line. The obturator externus can be easily 
 identified on both sides by its relation to the obturator membrane. 
 Behind it is seen the quadratus femoris, running from the tuberosity 
 of the ischium to the femur. The great sciatic nerve lies between the 
 quadratus and the gluteus maximus in the space between the tuber- 
 osity and the trochanter. The remainder of the muscular mass be- 
 tween the pelvis and femur belongs to the adductor group, but as 
 often happens, the divisions are so irregular that the individual mus- 
 cles cannot be certainly distinguished. The femoral vessels are 
 named on the right side and require no comment. On the left the 
 section passes below the origin of the profunda, and consequently 
 the relations are less simple. The femoral vein has already passed 
 behind the artery. The profunda artery and vein are situated on 
 their outer side. The external circumflex artery is seen winding 
 round the femur between the iliacus and the rectus. 
 
INDEX, 
 
 Aorta, p. 19 
 
 arch of, 20 
 division of, 5 1 
 Artery, carotid, 9, 12 
 creliac, 36 
 iliac, 51 
 
 pulmonary, 19, 20, 21 
 subclavian, 12 
 Axilla, 17 
 
 Bladder, 57 
 
 displacement of, 59 
 
 Caecum, 46 
 
 Chassaignac, tubercle of, 7 
 Colon, 40, 41,46,47, 54 
 Conus arteriosus, 23 
 Costal cartilages, 15 
 
 Defecation, mechanism of, 62 
 Diaphragm, action of, 32 
 Duodenum, 40 
 
 Fallopian tubes, 58 
 Fascia, cervical, 9, 12 
 
 lumbar, 47 
 Fossa, ischio-rectal, 59, 61 
 
 Heart, 23, 28 
 
 Kidney, 39, 42 
 
 Ligament, coronary, of liver, 36 
 sacro-sciatic, 59 
 suspensory, of diaphragm, 13 
 Liver, 35 
 Lung, apex of, 1 1 
 
 extra lobe of, 24 
 fissure of, 24 
 lower border of, 3 1 
 root of, 2 1 
 
 Mediastinum, anterior, 15 
 posterior, 21 
 
 Membrane, costo-coracoid, 13 
 
 Mesentery, 42 
 
 Muscle, abdominal, 42 
 deltoid, 13 
 erector spinae, 43 
 levator ani, 61 
 psoas, 54 
 scalenus, anterior, 1 1 
 
 minor, 12 
 
 serratus magnus, 14 
 sphincter ani, 62 
 sterno-mastoid, 8 
 trapezius, 14 
 
 Nerve, cervical, 8 
 lumbar, 45 
 phrenic, 8, 12, 17 
 pneumogastric, 9, 17 
 recurrent laryngeal, 8, 12 
 sacral, 53 
 
 Nipple, 23 
 
66 
 
 Index. 
 
 (Esophagus, course of, 16 
 
 end of, 31 
 Omentum, cavity of, 37, 41 
 
 gastro-splenic, 34 
 
 great, 41 
 Ovaries, 55 
 
 Pelvis, inclination of, 53 
 
 Pericardium, 19, 29 
 
 Perinaeum, 62 
 
 Peritoneum of bladder, 58, 59 
 colon, 41 
 liver, 36 
 spleen, 34 
 rectum, 59 
 
 Petit, triangle of, 43 
 
 Pleura, 15, 24, 31, 32, 39 
 
 Pylorus, 37 
 
 Rectum, 61 
 
 Respiration, mechanism of, 32 
 Rib, length of twelfth, 32 
 Ribs, relations to vertebrae, 1 1 
 
 Sacrum, 54 
 
 Scapula, 13 
 
 space beneath, 17 
 
 Sheath of carotid, 9 
 
 Sigmoid flexure, 54 
 
 Spigelius, lobe of, 37 
 
 Spinal cord, 45 
 
 Spine, cervical region of, 7 
 curves of, 49, 50 
 dorsal region of, 23 
 
 Spine, lumbar region of, 41 
 
 proportions of, 50 
 Spleen, 33, 34 
 Sternum, 27 
 
 position of top of, 1 1 
 Stomach, 37 
 Suture, neuro-central, 7 
 
 Thoracic duct, 15 
 
 Thorax, diameters of, 15, 23 
 
 Thymus, 15 
 
 Thyroid, 8 
 
 Trachea, division of, 15 
 
 Umbilicus, 45 
 Ureter, 51, 58 
 Uterus, 58 
 
 Valve, aortic, 19, 24 
 Eustachian, 28 
 mitral, 24 
 pulmonary, 19, 24 
 of renal veins, 39 
 tricuspid, 24, 28 
 Varicocele in the female, 59 
 Vein, jugular, 9 
 portal, 39 
 pulmonary, 21 
 Vena azygos, 21, 25 
 
 cava inferior, 28, 36 
 superior, 16 
 
 Winslow, foramen of, 37 
 
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