BK>SCNCE6UBRARy 
 
 /III 
 
 LIMAIY 
 
 CAUFOtNIA 
 
DESCRIPTIVE CATALOGUE 
 
 OF THE 
 
 TERATOLOGICAL SERIES 
 
 THE MUSEUM 
 
 OF THE 
 
 ROYAL COLLEGE OF SURGEONS OF ENGLAND. 
 
 BY 
 
 B. THOMPSON LO_WNE, M.R.C.S., 
 
 LECTURER ON PHYSIOLOGY AT THE MIDDLESEX HOSPITAL. 
 
 LONDON: 
 
 PRINTED FOR THE COLLEGE, 
 AND SOLD BY R. HARDWICKE, 192 PICCADILLY. 
 
 1872. 
 
PRINTED BY TAYLOR AND FRANCIS, 
 RE1> LION COURT, FLEET STREET. 
 
THE present Catalogue contains a description of the Spe- 
 cimens in the Museum formerly described in the ' Cata- 
 logue of the Contents of the Museum, Part V. compre- 
 hending the Preparations of Monsters and Malformed 
 Parts, 1831/ as well as of the Specimens of a similar 
 nature which have been added to the Collection since the 
 publication of that work. The whole have been rearranged 
 and redescribed by Mr. Lowne 5 to whom this duty has 
 been entrusted by the Council of the College. 
 
 W. H. FLOWER, 
 
 Conservator. 
 October 1st, 1872. 
 
 A 2 
 
INTRODUCTION. 
 
 " BY the classification of any series of objects, is meant the 
 actual or ideal arrangement together of those which are 
 like, and the separation of those which are unlike ; the pur- 
 pose of this arrangement being to facilitate the operations 
 of the mind in clearly conceiving and retaining in the me- 
 mory the characters of the objects in question " *. 
 
 In the animal and vegetable kingdoms there is a mar- 
 vellous interconnexion of organisms, perhaps genetic in its 
 origin, which enables us to classify them into groups based 
 upon purely structural considerations. Such a classifica- 
 tion has been well termed " morphological." 
 
 Amongst malformations there is no such interconnexion. 
 Parts of organisms which have no morphological relation 
 with each other are affected by causes which are very dif- 
 ferent in their nature and working. In such cases we must 
 not seek for a morphological classification ; we have to deal 
 with phenomena which may or may not be connected with 
 or dependent on each other, and the only satisfactory method 
 of arrangement must be physiological. 
 
 The classification of malformations on these principles, 
 to be entirely satisfactory, would require an intimate ac- 
 quaintance with the laws of abnormal development, and the 
 causes producing deviations from the normal standard. At 
 
 * Huxley, ' Lectures on the Elements of Comparative Anatomy,' p. 1. 
 
VI INTRODUCTION. 
 
 present we possess no such knowledge as this ; but what is 
 known affords sufficient data for a physiological classifica- 
 tion, which, if not entirely satisfactory, nevertheless ap- 
 proximates sufficiently nearly to a satisfactory arrangement 
 to fulfil the objects of classification to a very considerable 
 extent. Although the causes producing malformations are 
 themselves hidden in the deepest obscurity, their effects 
 are sufficiently definite to admit of a very clear diagnosis 
 and arrangement, whenever the first deviation of structure 
 can be perceived and studied apart from the various modifi- 
 cations which succeed and depend upon it. 
 
 The primary deviation from the normal type may be 
 looked upon as the immediate cause of the malformation. 
 All the successive changes and aberrations which depend 
 upon it bear a distinct morphological relation to each other 
 and to the primary deviation. Hence when malformations 
 belong to the same group (that is, when the primary de- 
 viations are the same), they bear a distinct morphological 
 relation to each other and admit of a morphological classi- 
 fication. 
 
 From these considerations it is evident that malforma- 
 tions due to the same cause affecting morphologically similar 
 parts may be arranged in groups, the members of which 
 are morphologically related, although the groups themselves 
 can only be arranged in classes by a knowledge of the 
 physiological relation which they bear to each other. Such 
 an arrangement is possible in many cases, because analogy 
 leads to the belief that the causes determining the occur- 
 rence of the malformations included in these groups are 
 similar. In some the first deviations from the normal 
 type are clearly of the same nature, or due to identical or 
 nearly identical causes ; we are then able to class the re- 
 sulting forms with certainty in one class ; but a number 
 occur in which the primary deviation is too obscure to admit 
 of this. Hence Bischoff argued that no satisfactory classi- 
 fication could be drawn from any but purely anatomical 
 grounds, and many authors have followed this principle 
 
PATHOLOGY AND TERATOLOGY. Vll 
 
 strictly ; every day, however, the difficulties of a physio- 
 logical classification will become less, and it may confi- 
 dently be predicted that in a few years this subject will 
 emerge from the darkness in which it has hitherto been 
 involved. 
 
 PATHOLOGY has for its domain the consideration of 
 the abnormal conditions of nutrition which occur in living 
 bodies. Every disease maybe looked upon as an abnormal 
 condition of nutrition, using that term in its widest sense, 
 whether the deviation be structural or apparently only 
 functional. 
 
 TERATOLOGY has for its domain the consideration of 
 abnormal conditions of development. In so far as the 
 function of development is separable from the functions of 
 maintenance and repair, Teratology is separable from Pa- 
 thology ; but there are a large number of intermediate 
 conditions in which it is impossible to distinguish between 
 aberrations of nutrition and of development. Again, there 
 are *various abnormal conditions of growth which may be 
 considered to belong to either class of phenomena. Hence, 
 by common consent, all the diseases peculiar to intra-uterine 
 life, together with certain abnormal congenital conditions 
 of growth, producing dwarfs and giants, have been assigned 
 to the Teratologist. 
 
 As we know that all the functions and parts of the living 
 body are prone to vary within certain limits, so we are 
 justified in believing that the process of development is 
 liable to a certain amount of variation. In some few cases 
 it can be shown that slight variations may occur in differ- 
 ent stages of the developmental process. Thus the occur- 
 rence of transposition, or situs mutatus, of the non-symme- 
 trical viscera is not very unfrequent ; and we owe to Von 
 Baer the following interesting theoretical explanation of its 
 occurrence : 
 
 " The embryo of a bird during the first thirty-six hours 
 lies with its abdominal surface downwards ; but in the 
 course of the third day of incubation in the egg of the 
 
Vlll INTRODUCTION. 
 
 common Fowl a change of position occurs, so that the left 
 side of the embryo comes to be laid on the adjacent surface 
 of the yelk. Von Baer had remarked, in very rare in- 
 stances in the bird's egg, more frequently in the ovum of 
 the Pig, the embryo lying with its right side towards 
 the yelk ; and he has ingeniously supposed that the re- 
 version of the viscera is connected with this malposition 
 of the embryo"*. If such be the case, transposition of 
 the viscera may be fairly regarded as a mere variation of 
 the developmental process. Again, the aortic arches are 
 liable to vary somewhat in the manner and period of their 
 obliteration. 
 
 It may be fairly assumed that variation is liable to occur 
 in the developmental process at any stage, and disease is 
 undoubtedly liable to do so. When either occurs in the 
 later stages, there is usually no difficulty in tracing the re- 
 sulting malformation to its proximal cause ; but when the 
 first deviation arises from variation in the process of de- 
 velopment or disease in the earlier stages of development, 
 the resulting malformation is often exceedingly complex, 
 so that it is only by a careful examination of a large series 
 of allied malformations that we can obtain any clue to the 
 nature of the original deviation. 
 
 Whatever the causes of embryonic disease and variation 
 may be, there can be no doubt that these conditions 
 react upon each other. Variation is extremely liable to 
 occur as an accompaniment to disease, probably because 
 new conditions arise ; and, on the other hand, disease fre- 
 quently results from variation. Again, disease passes by 
 insensible degrees into variation, and hence no definite line 
 can be drawn between malformations and varieties on the 
 one hand and diseases on the other. Ordinary varieties, 
 as well as the more marked degrees, of variation may be 
 fairly looked upon as the result of variations in the develop- 
 mental process ; they have therefore been grouped together 
 
 * Allen Thomson, Lond. & Edinb. Med. Journ. 1844. 
 
CLASSIFICATION. IX 
 
 into a single Class. Other deviations of form arise un- 
 doubtedly from intra-uterine disease, and certain abnormal 
 forms of nutrition give rise to dwarfs and giants ; these 
 have been arranged in three Classes Diseases, Arrests, 
 and Excesses of Growth. Two great Classes of malfor- 
 mations remain Arrests of Development, which are con- 
 nected with variations on the one hand and with diseases 
 on the other ; and Double Conditions, either of the whole 
 organism or of a limb or part, concerning the nature of 
 which much difference of opinion exists. 
 
 The- following six Classes have therefore been adopted in 
 the arrangement of the Teratological Collection : 
 
 Class I. Variation. 
 II. Duplicity. 
 
 III. Excess of Growth. 
 
 IV. Arrest of Growth. 
 
 V. Arrest of Development. 
 VI. Disease. 
 
 These great divisions, as has been already indicated, are 
 by no means to be looked upon as certainly fixed; they 
 are convenient groupings together of phenomena which are 
 apparently related to each other. Analogy leads us to sus- 
 pect that the causes in each Class are similar ; but further 
 investigation may lead to a redistribution of some groups, 
 and perhaps to some alterations in the number and nomen- 
 clature of the classes themselves. 
 
 Although the above-enumerated Classes are used as 
 the basis of classification in this Catalogue, it has been 
 found convenient to make them subservient to an artificial 
 grouping of the preparations in the following order : 
 
 Series I. Abnormal conditions in Plants. 
 
 II. Abnormal conditions of the Axis in Animals. 
 
 III. Abnormal conditions of the Limbs. 
 
 IV. Abnormal conditions of the Skin and its Ap- 
 
 pendages. 
 
INTRODUCTION. 
 
 Series V. Abnormal conditions of the Osseous and Mus- 
 cular Systems*. 
 
 VI. Abnormal conditions of the Sensory Organs. 
 VII. Abnormal conditions of the Heart and Vessels, 
 VIII. Abnormal conditions of Blood-glands. 
 IX. Abnormal conditions of the Digestive Organs. 
 X. Abnormal conditions of the Urinary and Genera- 
 tive Organs. 
 XI. Abnormal conditions of the Oviduct and Ova of 
 
 Birds f. 
 
 There are many practical reasons why the malformations 
 of each set of organs should be arranged in a separate Series ; 
 it facilitates comparison and reference, and is in accordance 
 with the general plan of arrangement of other parts of this 
 Museum. 
 
 The following considerations on the character and extent 
 of each of the six Classes which have been adopted may be 
 most conveniently discussed in the present portion of this 
 work. 
 
 Class I. VARIATION. 
 
 Syn. Hemiteries, Geoff. 
 
 The term variety is used by naturalists to designate the 
 result of gradually accumulated individual differences, which 
 are themselves slight variations. Some variations are, from 
 their very nature, of a more marked character than ordinary 
 
 * Abnormal conditions of the osseous and muscular systems are so 
 intimately connected with each other that they have been arranged in 
 a single Series. 
 
 f This Series consists of preparations of eggs which are evidently the 
 result of abnormal conditions or functional derangement of the oviduct, 
 and which throw little* or no light upon the more remarkable deviations 
 which occur in the other Series. It may be looked upon as supple- 
 mental to Series X., and it has therefore been placed last in the col- 
 lection. Specimens of abnormal condition of the oviduct have also been 
 arranged in this series, although, in strict conformity with the general 
 plan of the Catalogue, they should have been placed in Series X. : this 
 has been done because they elucidate, in some instances, the condition 
 of the eggs. 
 
VARIATION. XI 
 
 individual differences ; such are variations in the number 
 of organs : organs which are often repeated in an organism 
 are extremely prone to vary in number, and such variations 
 are clearly nearly allied to ordinary individual differences. 
 The effect of altered conditions frequently produces varia- 
 tion by a definite action, certain conditions always pro- 
 ducing similar variation ; such variation is usually more 
 considerable than ordinary individual differences. Varia- 
 tions sometimes arise suddenly, it may be by reversion to 
 an anterior type ; but in most cases it is either extremely 
 difficult or impossible to distinguish between reversions 
 and well-marked variations produced by other causes. 
 Variations are frequently transmitted from generation to 
 generation, and the abnormality sometimes increases, some- 
 times diminishes in intensity in each succeeding generation. 
 The more marked forms of variation are, however, rarer 
 and less truly transmitted than those which exhibit less 
 considerable deviation from the usual type. 
 
 The following principal groups of malformations have 
 been included under this Class : 
 
 1. Variations in the position of parts. Situs mutatus, 
 or transposition of the viscera, a condition already ad- 
 verted to. 
 
 2. Variations in the number of parts which are normally 
 repeated several times, such as cases of an additional or 
 deficient rib, or pair of ribs, or vertebra ; or, in plants, of 
 additional or deficient carpels, stamens, &c. 
 
 The various forms of polydactylism have also been in- 
 cluded under this Class, although some are evidently very 
 different to others in their nature. Any division founded 
 on the few specimens which are available would, however, 
 have been far too hazardous : it has therefore been thought 
 best to place all the specimens in one group ; and as the 
 greater part may probably be looked upon as variations, 
 the whole have been included in this Class. 
 
 It is a well-known law that multiple organs are more 
 prone to vary in number than those which are not repeated. 
 
Xll INTRODUCTION. 
 
 At an early stage of development the digits may fairly be 
 looked upon as multiple organs, as they differ in no way 
 from each other; it is not therefore surprising that the 
 number should frequently vary. As development proceeds, 
 however, and each digit becomes differentiated to its 
 peculiar characters, there is apparently a stronger and 
 stronger tendency for supernumerary digits to disappear. 
 The disappearance of these abnormal digits takes place 
 according to a well-defined law, which appertains not only 
 in all such cases, but also occurs normally in the Mammalia, 
 where the typical number of digits is less than five and 
 rudiments of the absent digits remain. 
 
 The metacarpal or metatarsal bone is the first to dis- 
 appear, and the phalanges remain loosely attached to the 
 skin and neighbouring bones by ligamentous tissue ; the 
 basal and median phalanges are lost next in order, and the 
 ungual phalanx in a rudimentary condition, or the ex- 
 tremity of the digit or nail, only remains to mark the 
 former existence of a digit. Sometimes, but very rarely, 
 a normal functional digit disappears in the same manner 
 (see No. 327). Many ruminants exhibit this condition in 
 rudimentary outer and inner digits. 
 
 Additional digits are occasionally developed, and usually 
 exhibit the characters of the next normal digit more or less 
 closely, oftener, however, resembling that of the opposite 
 hand or foot than the corresponding digit of the same 
 limb. It occasionally, but very rarely, happens that the 
 number of digits in the opposite limb is deficient ; and 
 this has given rise to the erroneous belief in compensation 
 of growth, loi de balancement (Geoffrey), between the two 
 extremities. 
 
 It is by no means rare in such cases for an additional 
 carpal bone to be intercalated between the normal bones ; 
 it usually resembles the trapezoid bone in the hand and the 
 second cuneiform bone in the foot. 
 
 It is worthy of careful consideration that the addition 
 of digits is far more frequent in hoofed than in unguiculate 
 
VARIATION. Xll 
 
 animals, and is often so excessive in them that the whole 
 manus or pes becomes doubled and usually exhibits the 
 appearance of a right and left manus or pes united together. 
 This condition is excessively rare in the Unguiculata ; one 
 case only is recorded in man *. 
 
 Another kind of polydactylism, confined to animals with 
 less than five toes, arises from the redevelopment of some of 
 the absent digits : No. 302 exhibits this condition in the 
 Horsef. A similar condition perhaps occurs in the domestic 
 Dog, where the inner toe of the pes is frequently developed : 
 it appears, however, to be abnormal in having three phalanges 
 instead of two ; at least if there are only two the metatarsal 
 bone is removed from its normal and very constant position. 
 In the St. Bernard Dog this inner toe is double, that is, six 
 toes characterize the pes ; so that in this case the supernu- 
 merary toes may probably be looked upon as entirely addi- 
 tional, as they are in the Dorking Fowl, where such digits 
 characterize the breed (see Nos. 294 and 295). Lastly, 
 sometimes a digit or a whole limb exhibits unmistakable 
 dichotomy : No. 307 presents this condition, and the 
 Musee Dupuytren contains a similar human foot. It is 
 not possible, however, to distinguish dichotomy of a digit in 
 all cases from mere addition ; it is probable, however, that 
 the conditions are really very distinct. The theory that 
 such additional parts originate from the fusion of twin 
 embryos may be looked upon as entirely superseded J. 
 
 3. Variations in the lobulation of the spleen. The num- 
 ber of transitional states between an entire spleen and one 
 much lobulated or divided render it probable that the most 
 marked cases of lobulation and division of that organ are 
 properly considered as mere varieties. 
 
 4. Variations in the form and arrangement of muscles ; 
 reversions to anterior types in the muscular and osseous 
 systems. 
 
 * J. J. Murray, Med.-Chir. Trans, vol. xlvi. p. 29. 
 t Wood-Mason, Proc. Asiat. Soc. Beng. 1871, p. 24. 
 J Schultze, Virchow's Archiv, Bd. xvii. p. 484. 
 
INTRODUCTION. 
 
 5. Variations in the disposition of the blood-vessels, and 
 especially of the large trunks given off from the aorta. 
 
 Class II. DUPLICITY. 
 
 This Class contains a vast number of very remarkable 
 conditions, at first sight extremely dissimilar, but clearly, on 
 closer study, intimately related in their mode of origin. 
 The forms included in this Class have been divided into 
 three Subclasses : 
 
 Subclass I. Dichotomy. 
 
 II. Homologous union. 
 III. Heterologous union. 
 
 I. Dichotomy, or fission as it is frequently called, con- 
 sists in the formation of two growing points in the place 
 of one, in such a manner as to produce a dichotomously 
 divided embryo or part, each half of the doubled portion 
 being complete in itself. This process occurs normally in 
 the production of a branching axis in plants, and is not un- 
 frequent in the multiplication of Ccelenterates, in the 
 division of Coral-polypes and certain branched Hydrozoa. 
 The use of the term fission to designate this condition is 
 unfortunate, as it implies the division of an already formed 
 part ; whilst Dichotomy in both animals and plants, either 
 normal or abnormal, as has been carefully pointed out by 
 Dr. Maxwell T. Masters in his 'Vegetable Teratology/ 
 consists in the simultaneous production of two points 
 of growth. Fission amongst coral-polypes is of this kind, 
 a fact strongly insisted on by Milne-Edwards. The term 
 has, indeed, been used to designate a totally distinct 
 phenomenon in the Infusoria, where an already formed 
 organism undergoes division. Dichotomy may probably 
 arise from a cleavage of the original cells, out of which a 
 part is developed ; but we know nothing certainly on this 
 point. 
 
DUPLICITY. XV 
 
 Amongst the Vertebrata dichotomy of the axis is by no 
 means unknown ; it may occur at either extremity, but the 
 posterior extremity is most frequently affected. This con- 
 dition originates in dichotomy of the primitive groove and 
 notochord. Many discussions have been held -and much 
 difference of opinion exists as to its origin. That there is 
 but a single germinal area is undoubted* ; but the question 
 at issue is whether there were originally two grooves and two 
 notochords arising from independent sources (i. e. possibly 
 from two vesicles of Purkinje being present in a single ovumf 
 or from the original fusion of two yelks) or from an originally 
 simple ovum. The former hypothesis is unsubstantiated, 
 since the occasional presence of two vesicles of Purkinje, 
 or the fusion of two yelks in an ovum, which we do not 
 know will produce a double embryo, cannot be regarded in 
 the light of evidence ; and the hypothesis entirely fails to 
 account for the presence of a single blastoderm, a single 
 germinal area, or a dichotomous embryo : on the other hand, 
 the view that excess of formative power or nutriment pro- 
 duces a tendency to the complete or partial doubling of the 
 embryo upon a single blastoderm, by the formation of two 
 points of growth in the place of one, is borne out by 
 numerous facts. 
 
 The doubling of a single limb, although excessively rare, 
 occurs at times (see No. 307), bearing out the view that a 
 double axis is the result of dichotomy. The observations 
 of Lereboullet on the ova of fishes points to the same 
 conclusion. He says : 
 
 " Le bourrelet en effet constitue le veritable germe em- 
 bryonnaire, germe toujours simple, unique comme le vitellus 
 que le blast oder me recouvre, mais susceptible quand le 
 developpement se derange, de vegeter comme la substance 
 dont se compose le corps des polypes, et de produire des 
 formes variees qui montrent toujours une tendance manifeste 
 
 * Vrolik, Allen Thomson, and others have placed this matter 
 beyond doubt. 
 
 f M. Coste, Coinptes Rendus, 1855, p. 931. 
 
XVI INTRODUCTION. 
 
 a revenir au type primitif de 1'espece" *. Lereboullet states 
 that this condition of the germinal disk gives rise to the 
 formation of a more or less completely double primitive 
 groove and notochord, although the tendency to revert to 
 the primitive type often causes the two grooves to coalesce at 
 one or both extremities, or throughout their entire length. 
 
 II. The second Subclass, Homologous union, consists of 
 monsters formed by the union of two distinct embryos 
 adherent by the fusion of homologous parts ; each rib of 
 the one, for instance, becomes fused with the corresponding 
 rib of the other, and the other organs are all similarly 
 united. The fact that such embryos originate in all cases 
 upon a single yelk has been strongly insisted upon by most 
 teratologists since the time of Vrolik, and double embryos 
 on one yelk have been observed in numerous instances. 
 Whenever the structures formed from the inner layer of 
 the blastoderm, the intestinal canal and liver, are continuous, 
 as they are in every case in the collection as well as in 
 nearly if not in all the cases on record, it is impossible to 
 conceive that the embryos could have originated in any 
 other manner, since the adhesion of the parietes of the 
 embryos by their external surfaces could not account for 
 the continuity of the alimentary canal. M. Canaille 
 Dareste believes, however, that cases of homologous union 
 occur between embryos formed on separate yelks, oc- 
 casionally at least. 
 
 In homologous union the dorsal groove, instead of 
 being only partially double, as in dichotomy, is completely 
 double, and the two embryos are formed so close to each 
 other that the visceral laminae become united. As union 
 takes place before the differentiation of distinct organs oc- 
 curs, these are formed in continuity with each other. The 
 differentiation is probably gradual ; the ribs, for instance, 
 instead of growing forwards from the spine and meeting 
 in the mesial line, are probably gradually evolved from the 
 cells of the visceral laminae. This evolution is continuous 
 * Comptes Rendus, 1855, pp. 885 and 1029. 
 
DUPLICITY. XV11 
 
 throughout their entire length, but proceeds most rapidly 
 in the dorsal region, so that they appear to grow forwards. 
 The so-called affinity of " soi pour soi " of Geoffroy is 
 probably quite imaginary ; for organs, when differentiated 
 before union, probably in no case become united to homo- 
 logous parts. This is well seen in preparations Nos. 120 
 and 123 to 130, 138, &c. 
 
 It may be said to be a well-defined law that structures 
 which are united before differentiation become double by 
 the development of homologous structures in continuity 
 with each other, a symmetrical double organ being formed ; 
 whilst structures which are first developed and then 
 united become fused irregularly with each other, giving 
 rise to deformed and unsymmetrical structures. In such 
 cases bone usually unites with bone, from the absorption 
 of all intermediate tissues being effected by the pressure 
 to which they are subjected between the two growing 
 bones. Large portions of structures so united are com- 
 monly deficient from absorption or atrophy. 
 
 III. Cases of Heterologous union form the third sub- 
 class. In these the parts of the two embryos are irregu- 
 larly united, the adhesion resulting from the union of un- 
 like structures. In most cases, at least, these malforma- 
 tions result, like those in the two previous subclasses, from 
 the formation of a double embryo on a single yelk. Several 
 extremely complicated results occur from heterologous union; 
 but they are best studied in individual cases. In some few 
 instances of heterologous union it is possible that the second 
 embryo may result from a second ovum, impregnated at a 
 later date, finding its way into the cavity of the mem- 
 branes of an earlier impregnation. No evidence can, 
 however, be adduced in support of this view. 
 
 Twins united in a common choronic or amniotic cavity 
 are probably the normal result of the formation of a double 
 embryo upon one yelk. There is a continuous and unbroken 
 series of forms commencing with dichotomous and double 
 monsters, passing through twins with a common cord and 
 
 b 
 
XV111 INTRODUCTION. 
 
 placenta, or a common amnion and distinct cords, to those 
 which have separate ammo tic sacs but a common chorion. 
 
 It is almost as difficult to conceive that two amniotic 
 sacs from distinct yelks should unite by their edges as it is 
 that two embryos should unite by their visceral laminae 
 when enclosed in distinct amnia. Moreover, the yelk-cap- 
 sule is probably persistent, and a seam at least would be 
 apparent if the amnia were fused at a later period of deve- 
 lopment by the absorption of those portions by which they 
 are in contact. M. Dareste believes that the amniotic sacs 
 produced from distinct yelks become fused together occa- 
 sionally by their edges, and M. Broca has recorded several 
 cases in which two amnia formed from distinct yelks com- 
 municate or form a single amnion *. It would be of extreme 
 importance to discover whether, in such cases, some traces 
 at least of the primitive septum do not remain. 
 
 The formation of double monsters may probably be 
 looked upon, therefore, as an arrested attempt at something 
 very like zooid reproduction, perhaps due to the germinal 
 disk in its earliest state undergoing division, analogous to 
 that which occurs as a normal mode of reproduction amongst 
 the lower forms of life by a kind of reversion to a primitive 
 type. This view will doubtless commend itself to some 
 minds on mature consideration, although it may perhaps 
 appear improbable to others. 
 
 If two complete primitive grooves occur, any arrest in 
 the growth of the blastoderm between them, or their too 
 close approximation at their first formation, would obviously 
 give rise to the subsequent union of the resulting embryos. 
 These views are ably expounded by Dr. B. Schultze, in his 
 essay 'Ueber anomale Duplicitat der Axenorgane'f, where 
 he proposes a subdivision of double malformations on 
 theoretical grounds, which is essentially the same as that 
 adopted in the following pages. 
 
 * C. Dareste, " Sur les ceufs a double germe," Ann. Sc. Nat. 1862, 
 t. xvii. pp. 48 & 49. 
 
 f Virchow's Archiv, Bd. xvii. p. 479. 
 
ARREST AND EXCESS OF GROWTH. XIX 
 
 The fusion of distinct buds in plants, as in syncarpy 
 (Prep. Nos. 6 to 14), is clearly a condition analogous to 
 the union of embryos originating on a single yelk : in both 
 cases the united growths probably originate by a similar 
 process, the formation of two centres of growth in the place 
 of one. A similar mode of union occurs normally between 
 contiguous zooids in the Gorgonidse, or fan corals. 
 
 In the eggs of birds three distinct conditions occur : 
 First, there may be two yelks enclosed in a single shell ; 
 this condition may give rise to two young, and if they 
 become united they only adhere by heterologous parts, 
 or possibly by the integument of the umbilicus *. Se- 
 condly, there may be two cicatrices on one yelk : in this 
 case the yelk is virtually equivalent to two mammalian 
 yelks, as the cicatrix is the homologue of the mammalian 
 yelk, the great food-yelk being absent in this Class f. Or, 
 thirdly, two embryos may be formed on the same cicatrix : 
 this condition is the most frequent, and gives rise either to 
 twin chicks (?) or to double monsters. 
 
 Dichotomy, as already stated, very rarely affects a limb 
 or digit ; it is liable to occur in the kidneys. 
 
 Doubling of the cavities of the heart, bladder, and uterus 
 are malformations totally unlike those arising from dicho- 
 tomy. The latter organ is certainly doubled by arrest of 
 development. " 
 
 Classes III. & IV. ARREST AND EXCESS OF GROWTH 
 
 Include, first, dwarfs and giants, which are either the effect 
 of variation of nutrition or development ; and, secondly, 
 cases of partial excess or arrest, which are more nearly allied 
 to ordinary disease : these may be considered as cases of 
 nitra-uterine hypertrophy or atrophy. 
 
 * There is no improbability in such union, and it appears to have 
 been observed. M. Camille Dareste thinks this adhesion occurs. 
 
 t E. van Beneden, ' Rccherches sur la composition et la significa- 
 tion de 1'ceuf.' Bruxelles, 1870. 
 
XX INTRODUCTION. 
 
 Class V. ARREST OF DEVELOPMENT. 
 
 The most numerous and complicated groups of abnormal 
 conditions are included in this Class ; but as it is extremely 
 comprehensive and well defined, and as two or more forms 
 of arrest are sometimes united in a single malformation, it 
 is extremely doubtful whether any good would arise in the 
 substitution of several Classes in its place, at least with our 
 present knowledge of the subject. 
 
 The various forms of arrest may be epitomized in the 
 following manner : 
 
 I. The normal evolution of an embryonic structure 
 may fail, although its growth continues, so that an enlarge- 
 ment of the embryonic condition results. It occurs in the 
 external generative organs of the female, giving rise to a 
 similarity to the male. The condition has the appearance 
 of excessive development, but it is clearly due to the absence 
 of the usual developmental change. Doubling of the female 
 uterus by a septum, and the growth of the Miillerian duct 
 and genital cord into an enormous organ in the male, are 
 examples of this phenomenon. Some of the various kinds 
 of atresia may probably be of a similar character. 
 
 II. The second form of arrest of development is apparently 
 due to an early arrest of growth in the lateral halves of such 
 organs as are formed by the union of two symmetrical 
 halves ; in extreme cases there is usually great accompany- 
 ing defect of development in the lateral parts. Persist- 
 ence of a cleft only, inasmuch as it is the persistence of an 
 earlier condition, is an arrest of development. Fissure of 
 the sternum, abdominal wall, palate, iris, &c. are of this 
 kind, as are also the states known as ectopia vesicae, epi- 
 spadias, and hypospadias. 
 
 III. The third form also arises from, or is at least accom- 
 panied by, arrest of growth and atrophy, so that an organ 
 or part may be rudimentary, minute, or entirely absent. 
 When median structures fail in this way in the axis of the 
 body, the lateral parts coalesce at too early a period and 
 
ARREST OF DEVELOPMENT. XXI 
 
 fusion results, with the absence of the parts which nor- 
 mally intervene. The axis of the skull may fail to a greater 
 or less extent, a condition accompanied by fusion of the 
 eyes (cyclopia) and absence of the median structures of the 
 nose, and usually accompanied by an arrested condition of 
 the brain, in which, although growth has continued, evolu- 
 tion has not; it probably arises from defective nutrition 
 or atrophy of the axis of the skull, and may be considered 
 as the result of very early embryonic disease. 
 
 The various forms of facial fusion (Cyclopia, Ethmocepha- 
 lus, &c.), certain defective conditions of the limbs (Perome- 
 lid), fusion of the limbs (Sympodid], and deficiencies of other 
 parts are also probably of this kind. 
 
 IV. In the fourth form of arrest, differentiation fails at an 
 early period ; this is seen most frequently in the intercostal 
 spaces, a complete layer of bone being formed in the place 
 of intercostal muscles between an adjacent pair of ribs. It 
 usually accompanies severe forms of arrest in other parts. 
 Sometimes no muscles exist, the whole body being formed 
 of dense connective tissue, containing bones and cartilages. 
 Other examples of this kind of arrest, which might fairly 
 be called histological, occur. 
 
 V. Lastly, the heart may undergo an arrest of develop- 
 ment and atrophy at a very early period, so that ,an acardiac 
 foetus results. Such malformations always exhibit great 
 histological arrest ; many of the organs remain in an em- 
 bryonic condition, although they may increase in size. 
 Some parts become so altered that they can scarcely be 
 recognized. The head is usually completely absent, or it 
 consists of a mere bony cyst. 
 
 Functionally active organs always undergo considerable 
 after modification whenever their development has been 
 arrested : this is especially seen in the heart. Other parts 
 exhibit the conditions in a less degree. The pelvis No. 424 
 is a good example of this phenomenon : the pubic bones 
 have been arrested in their growth in consequence of their 
 taking no part in the support of the body, and they have 
 
XX11 INTEODUCTION. 
 
 become widely separated by the manner in which the ilia 
 and sacrum supported the weight of the trunk. 
 
 With regard to the nature of the origin of arrest nothing 
 is known positively. Like all malformations, some forms 
 appear closely allied to variations, some to diseases. In 
 arrest, however, the variations, if they be such, take the 
 form of reversions. This may be more apparent than real ; 
 but in some Ceases, where growth continues and evolution 
 does not, it appears as if the parts are actually developed in 
 conformity with an anterior type rather than simply arrested 
 in their formation. Bilocularity of the human uterus, the 
 formation of uterine cornua, enlargement of the clitoris, 
 development of the uterus masculinus, hypospadias, the 
 formation of a cloaca, webbing of the fingers, arrest of the 
 ventricular septum of the heart, and the persistence of a 
 spiracle uniting the pharynx and auditory meatus are ex- 
 amples of this kind. 
 
 Class VI. DISEASE. 
 
 The last class of malformations consists of intra-uterine 
 diseases and their results. The most marked forms are 
 those of spinal and appendicular deformity, and dropsy of 
 the central canal of the nervous system, giving rise to 
 hydrocephalus, epicephalocele, spina bifida, &c. 
 
 It will be observed that no class has been formed for 
 malformations from excess of development ; for it may well 
 be doubted if any such exist, unless under the forms of 
 variation or duplicity. 
 
 There are, however, some cases which might possibly be 
 considered as the result of excess in the developmental 
 process ; although, without more evidence, it appears inju- 
 dicious to erect a class which all observations tend to render 
 more and more hypothetical in its nature. Certain fishes, 
 for instance, occasionally exhibit a very remarkable form of 
 hermaphrodism in which a portion of an ovary is developed 
 as a testis, whilst the remainder becomes a perfect ovary. 
 
DISEASE. XX111 
 
 It is by no means certain, however, that the testis should be 
 looked upon as an excessive development ; it is equally 
 possible that the ovary is formed by an arrest of a genera- 
 tive gland which would otherwise have been a testicle. 
 Sometimes an additional septum is formed in the heart ; 
 but this may arise from mere hypertrophy of the musculi 
 papil lares. 
 
 In conclusion, attention is drawn to the desiderata 
 in this collection ; for although it is a very splendid one, 
 containing many almost unique preparations, it has 
 deficiencies which could easily be supplied. Many forms 
 of the lesser degrees of malformation which possess great 
 practical interest, as hare-lip, hypospadias, &c., are nearly 
 unrepresented ; whilst no collection has hitherto been made 
 of variations in the conformation of muscles, bones, and 
 vessels, which could not fail to possess great value, and to 
 afford material aid in the study of Teratology. 
 
CONTENTS, 
 
 SERIES I. ABNORMAL CONDITIONS IN PLANTS. 
 
 No. of 
 Preparations. 
 
 CLASS I. VARIATION. 12 
 
 CLASS II. DUPLICITY. ^ * 
 
 Subclass I. Dichotomy 3 4 
 
 Subclass II. Homologous union. 
 
 a. Union of stems 5 oa 
 
 b. Union of fruit 6 14 
 
 c. Union of seeds 15 
 
 d. Union of embryos 16 17 
 
 SERIES II. ABNORMAL CONDITIONS AFFECTING 
 THE AXIS IN ANIMALS. 
 
 CLASS I. VARIATION. 
 
 a. Situs mutatus 18 19 
 
 CLASS II. DUPLICITY. 
 
 Subseries I. IN INVERTEBRATES. 
 
 Subclass I. Dichotomy 20 
 
 Subseries II. IN FISHES. 
 
 Subclass II. Homologous union 21 22 
 
 Subseries III. IN AMPHIBIA. 
 
 Subclass IY. Heterologous union 23 
 
 Subseries IV. IN REPTILES. 
 Subclass I. Dichotomy. 
 
 A. Anterior Dichotomy 24 27 
 
 B. Posterior Dichotomy ' . . . 28 
 
 Subseries V. IN BIRDS. 
 
 Subclass I. Dichotomy. 
 
 A. Anterior Dichotomy 2932 
 
 B. Posterior Dichotomy 3341 
 
 Subclass II. Homologous union. 
 
 a. Pleuropagus 42 44 
 
 b. Hypogastrodidymus 45 46 
 
XXVI CONTENTS. 
 
 No. of 
 Preparations. 
 
 Subclass IV. Heterologous union 47 48 
 
 Subseries VI. IN MAMMALS. 
 Subclass I. Dichotomy. 
 
 A. Anterior Dichotomy. 
 
 * In Animals. 
 
 a. Diprosopus 49 61 
 
 b. Dicephalus 62 64 
 
 B. Posterior Dichotomy. 
 
 * In Animals. 
 
 a. Dipygus 6567 
 
 b. Schizorhachis 68 80 
 
 c. Schizocotis 81 84 
 
 d. Schizocephalus 85 86 
 
 ** In the Human foetus. 
 
 a. Schizorhachis 87 
 
 b. Schizocotis 88 89 
 
 C. Antero-posterior Dichotomy 90 94 
 
 Subclass II. Homologous union. 
 
 A. Prozygosis 9598 
 
 B. Opisthozygosis 99 104 
 
 C. Parazygosis. 
 
 a. Xiphopagus 105 
 
 b. Thoracopagus 106 117 
 
 c. Pleuropagus 118 121 
 
 d. Pygopagus 122 
 
 Subclass III. Homologous union with dichotomy. 
 
 Subclass IV. Heterologous union. 
 
 A. By Impaction. 
 
 a. Between the halves of the sternum . . 123 130 
 
 b. Between the facial arches 131 133 
 
 B. By Inclusion 134 137 
 
 C. By Adhesion. 
 
 a. Craniopagus 138 
 
 b. Ischiopagus 139 
 
 CLASS III. EXCESS OP GROWTH. 
 
 [Arranged in the Osteological Series. ,] 
 CLASS IV. ARREST OP GROWTH. 
 
 [Arranged in the Osteological Series.] 
 CLASS V. ARREST OP DEVELOPMENT. 
 Subclass I. Cranial arrest. 
 
 IN PISHES 140 142 
 
 IN BIRDS 143144 
 
 IN MAMMALS. 
 A. Facial arrest . , 145159 
 
CONTENTS. XXVI 
 
 No. of 
 Preparations. 
 
 B. Prosencephalic arrest. 
 
 a. Khinocephalus 160178 
 
 b. Arhynchus 179186 
 
 c. Anopia 187189 
 
 C. Mesencephalic arrest 190 19 1 
 
 D. Epencephalic arrest. 
 
 a. Agnathia 192 193 
 
 b. Synotia 194 199 
 
 E. Prostho-epencephalic arrest. 
 
 a. Cyclocephalus 200209 
 
 b. Nanocephalus 210222 
 
 c. Acephalus 223 227 
 
 Subclass IT. Posterior axial arrest. 
 
 a. Sympodia 228233 
 
 b. Monopodia 234237 
 
 Subclass III. Arrest of the tvhole axis 238 246 
 
 Subclass IV. Defective closure of the thoracic and 
 
 abdominal cavities. 
 
 a. Fissure of the sternum 247 248 
 
 b. Ectopia of the abdominal viscera .... 249 251 
 
 c. Deficiency of the diaphragm 252 255 
 
 CLASS VI. MALFORMATIONS OF THE AXIS FROM 
 
 DISEASE. 
 Subclass I. Curvature of the axis. 
 
 a. Simple curvature , . . . 256 261 
 
 b. With ectopia of the viscera 262 264 
 
 Subclass II. Dropsy of the axial canal of the cere- 
 
 bro -spinal system. 
 
 a. Spina bifida 265277 
 
 b. Occipital deficiency 278 279 
 
 c. Epicephalocele 280281 
 
 Subclass III. Anencephalus 282292 
 
 SERIES III. ABNORMAL CONDITIONS OF THE 
 LIMBS. 
 
 I. IN INVERTEBRATES 293 
 
 II. IN VERTEBRATES. 
 CLASS I. VARIATION. 
 
 A. In the number of digits. 
 
 a. Polydactylus 294313 
 
 CLASS II. DUPLICITY. (See Polydactylus.) 
 
XXV111 CONTENTS. 
 
 No. of 
 Preparations. 
 
 CLASS III. EXCESS OF GROWTH 314 
 
 CLASS TV. ARREST OF GROWTH. 
 
 A. In the Digits . 315317 
 
 B. In the Limbs 318322 
 
 CLASS V. ARREST OF DEVELOPMENT. 
 
 A. Of the Digits. 
 
 a. Aschistodactylus 323 326 
 
 b. Perodactylus 327 
 
 B. Of the Limbs. 
 
 a. Ischnomelia 328332 
 
 b. Peromelia 333338 
 
 c. Micromelia 339 
 
 d. Amelia 340342 
 
 CLASS VI. MALFORMATIONS FROM DISEASE. 
 
 A. Distortion. 
 
 a. Talipes 343349 
 
 b. Congenital curvature 350 351 
 
 c. Congenital dislocation 352 353 
 
 SERIES IV. ABNORMAL CONDITIONS OF THE 
 
 SKIN AND ITS APPENDAGES . 354363 
 
 SERIES V. ABNORMAL CONDITIONS OF THE 
 OSSEOUS AND MUSCULAR SYSTEMS. 
 
 A. Of the Sternum and Ribs , . 364369 
 
 SERIES VI. ABNORMAL CONDITIONS OF THE 
 SENSORY ORGANS. 
 
 A. Of the Eye 370373 
 
 SERIES VII. ABNORMAL CONDITIONS OF THE 
 HEART AND VESSELS. 
 
 CLASS I. VARIATION. 
 
 a. Abnormal arrangement of the vessels . 374 375 
 
 b. Situs mutatus 376 
 
 c. In the number of arterial valves. 
 
 d. Division of a ventricle 377 
 
 CLASSES II., III., & IV. have not occurred in this Series. 
 
CONTENTS. XXIX 
 
 No. of 
 
 Preparations. 
 CLASS Y. AEBEST OF DEVELOPMENT. 
 
 a. Arrested closure of the ductus arteriosus 378 
 
 b. Of the foramen ovale 379383 
 
 c. Of the ventricular septum 384 387 
 
 d. Of an artery. 
 
 e. Premature closure of ductus arteriosus 
 
 or foramen ovale. 
 
 f. Of a valve 388 
 
 g. Deficiency of the pericardium. 
 
 SERIES VIII. ABNORMAL CONDITIONS OF 
 BLOOD-GLANDS. 
 
 A. Of the Spleen 389390 
 
 SERIES IX. ABNORMAL CONDITIONS OF THE 
 DIGESTIVE ORGANS. 
 
 A. Of the Teeth 391393 
 
 B. Of the Alimentary Canal. 
 
 CLASS Y. AEREST OF DEVELOPMENT. 
 
 (The other Classes have not occurred in this Series.) 
 
 a. Of the pharynx and oesophagus .... 394 396 
 
 b. Atresia of the rectum 397 407 
 
 SERIES X. ABNORMAL CONDITIONS OF THE 
 URINARY AND GENERATIVE ORGANS. 
 
 CLASS II. DUPLICITY. 
 
 (Classes I., III., & IV. have not occurred in this Series.) 
 Subclass I. Dichotomy. 
 
 a. Of the Tcidney and ureter 408418 
 
 CLASS V. AREEST OF DEVELOPMENT. 
 
 A. Of the Kidney 419 
 
 B. Of the anterior Abdominal wall and 
 
 Bladder. 
 
 a. Epispadias 420 
 
 b. Ectopia vesicce 421 425 
 
XXX CONTENTS. 
 
 No. of 
 
 Preparations. 
 
 C. Of the Urino -generative Tract. 
 * In the Human subject. 
 
 a. Hypospadias 426 
 
 b. Androgyny 427 
 
 c. Gynandry 428 430 
 
 ** In Animals. 
 
 a. Hypospadias 431 434 
 
 b. Androgyny 435 444 
 
 c. Gynandry 445 
 
 d. HermapJirodism 446 449 
 
 B. Of the Uterus. 
 
 a. Double uterus 450 453 
 
 b. Atresia of the os . 454 
 
 SERIES XI. ABNORMAL CONDITIONS OF THE 
 OVIDUCT AND OVA OF BIRDS. 
 
 A. Of the Oviduct. . . . 455456 
 
 B. Of the Ova. 
 
 a. Twin Eggs 457 460 
 
 b. Of the coverings of the yelk 461466 
 
 c. Pseudo-Eggs 467 472 
 
 d. Included Eggs or Pseudo-Eggs 473 477 
 
 e. Fibrinous masses from the Oviduct . . 478 479 
 
CATALOGUE. 
 
 SERIES I. 
 
 ABNORMAL CONDITIONS IN PLANTS. 
 
 J-HIS small series illustrates very clearly the difference be- 
 tween Variation, Dichotomy, and Homologous union, and throws 
 much light on the nature of similar malformations in the animal 
 kingdom. 
 
 Class I. VARIATION. 
 
 1. A Walnut with three carpels instead of two, the normal 
 
 number. 
 
 This is a true case of variation. The additional carpel has pre- 
 cisely similar relations to each of the normal carpels, and bears no 
 evidence of having arisen from the fission of either of these. In 
 many cases an additional part arises in plants from the develop- 
 ment of one which exists at an early stage, but which usually fails 
 by abortion. No third carpel, however, exists normally at any 
 period of development in the fruit of the Walnut. 
 
 Presented by J. Quekett, Esq., 1859. 
 
 2. The fruit of a Pea with three carpels instead of one. The 
 
 third carpel is very small. There is but a single seed, 
 and this is borne by the largest carpel. 
 
 This case differs from the former in several particulars. The 
 two additional carpels are by no means equally developed with the 
 normal one ; many of the allies of the Pea (Leguminosce) normally 
 possess three carpels, whilst the Walnut- tribe (Juglandece) either 
 have two or four. The first case is probably one of simple varia- 
 tion ; this is possibly one of reversion. 
 
 B 
 
2 ABNORMAL CONDITIONS IN PLANTS. 
 
 Class II. DUPLICITY. 
 
 Subclass I. Dichotomy. 
 
 3. A frond of the common Hart V tongue Fern, dichotomous in 
 
 its upper part from fission. Presented by Mr. Clift, 1808. 
 
 4. A dichotomous ear of Wheat^ in which the culm is single. 
 
 Presented by Mr. Sear son, 1871. 
 
 Subclass II. Homologous union. 
 
 a. Union of stems (Fasciatiori). 
 
 5. A double head of Cowslip-flowers with the flower-stalks 
 
 slightly adherent through their entire length. 
 
 Presented by Mrs. Scott, 1872. 
 
 50. A triple head of Teasel, probably produced by the cohesion 
 of three axes. 
 
 b. Union of fruit (Syncarpy). 
 
 6. Two Quinces on a single peduncle united by fusion of their 
 
 sarcocarps. Presented by W. J. B. Smith, Esq., 1858. 
 
 7. Two Cherries united in the same manner. 
 
 Presented by T. H. Stewart, Esq. 
 
 8. A similar specimen. 
 
 Presented by Prescott G. Hewett, Esq., 1871. 
 
 9. Two Apples united in the same manner. Hunterian. 
 
 10. Two Apples similarly united, divided vertically to show the 
 
 divergence of the axes of the two fruits. The tree from 
 which this fruit was obtained produced a crop of similar 
 fruit every year. Presented by Sir A. Carlisle, 1829. 
 
 1 1 . Two small Cucumbers on a single peduncle, adherent through 
 
 their entire length, cut through transversely to show the 
 manner in which they are united. 
 
 Presented by W. J. B. Smith, Esq. 
 
 12. Two Cucumbers similarly united throughout two thirds of 
 
 their length. Presented by W. Clift, Esq., 1829. 
 
 1.3. Two Cucumbers similarly united; the growth of one has 
 been arrested, however, at a very early stage. 
 
 Hunterian. 
 
ABNORMAL CONDITIONS IN ANIMALS. 3 
 
 14. Three Spanish Nuts united by their pericarps : union seems 
 
 to have taken place during the later stages of develop- 
 ment, as it is not complete, and the adjacent portions of 
 the pericarps are flattened. A section has been made 
 through the nuts. Presented by Prof. Flower, 1871. 
 
 c. Union of seeds (Synspermy). 
 
 15. Two Bean-seeds united by their cotyledons near their hila, 
 
 which are distinct. The testa is continuous over the two 
 seeds. Hunterian. 
 
 d. Union of embryos (Synophy). 
 
 16. Two seedling Orange-plants attached by their cotyledons; 
 
 they were produced from a single seed. There are four 
 cotyledons, but the two between the embryos are smaller 
 and are closely adherent to one another. 
 
 Presented by B. T. Lowne, Esq., 1871. 
 
 17. Three seedling Orange-plants growing from a single seed. 
 
 The cotyledons are united between the embryos. The 
 third embryo is very much smaller than the other two. 
 
 " It occurs, not unfrequently, in the Orange and Hazel that more 
 than one embryo is developed in a single testa ; and this condition 
 is very common in the Coniferse, Cycas, the Onion, and the Mis 
 seltoe. Now and then a union of these embryos takes place." 
 (Lindley's ' Introduction to Botany.') 
 
 Presented by B. T. Lowne, Esq., 1871. 
 
 SERIES II. 
 
 ABNORMAL CONDITIONS AFFECTING THE AXIS 
 IN ANIMALS. 
 
 Class I. VARIATION*. 
 
 a. Situs mutatus (transposition of the viscera). 
 
 This is the only class of phenomena affecting the whole axis 
 which can be regarded as a variation. In the earliest stages 
 
 * For remarks on the nature of Classes and Subclasses see the In- 
 troduction. 
 
 B2 
 
4 ABNORMAL CONDITIONS OF THE AXIS. 
 
 of the embryo the yelk is on its ventral surface, but soon the 
 left side turns towards the yelk. Transposition of the viscera, 
 as was long ago pointed out by Von Baer, probably arises from 
 this turn taking place in the opposite direction, so that the right 
 side of the embryo comes to lie upon the yelk. It is not a 
 little remarkable that so slight a deviation should be so very rare 
 and so frequently accompanied by grave malformations. In 
 cases of transposition there appears to be a strong tendency in 
 many organs to revert to their normal position ; thus transposi- 
 tion is frequently partial. In the Mollusca transposition occurs 
 commonly in some few genera, and has long been considered 
 as a variation ; one species of Whelk is constantly reversed. 
 
 18. The trunk of a human foetus with complete transposition of 
 
 all the viscera. The small intestines have been removed. 
 
 Mus. Heaviside. 
 
 19. An injected and dried preparation of the heart and large 
 
 vessels, with some of the abdominal viscera of a human 
 adult, in which all the parts are transposed. The pre- 
 paration includes the stomach, liver, spleen, and caecum. 
 
 Class II. DUPLICITY. 
 Subseries I. IN INVERTEBRATES. 
 
 Subclass I. Dichotomy. 
 
 20. An Earthworm with the posterior third of the body sym- 
 
 metrically double. Presented by W. Clift, Esq., 1810. 
 
 Subseries II. IN FISHES. 
 
 Subclass II. Homologous union. 
 
 21. Two specimens, each consisting of two newly hatched Trout 
 
 united by the posterior portions of the ventral aspect. 
 The single yelk-sac is attached to the lower specimen, 
 showing their origin from a single yelk. 
 
 Presented by the Duke of Wellington, 1870. 
 
 22. Two small Sharks united in the same manner as the Trout 
 
DUPLICITY. 5 
 
 in the last preparation. The remains of a single yelk- 
 sac (pseudo -placenta) is seen between the pectoral fins. 
 
 A female Shark was taken by the donor (mate of a vessel) in 
 the Indian Ocean (34 S. lat., 90 E. long.). When brought on 
 deck and cut up, about thirty living young escaped from its abdo- 
 men. The specimen presented lived for two days in a bucket of 
 sea-water. 
 
 Presented by E. Bestard, Esq., 1866. 
 
 Subseries III. IN AMPHIBIA. 
 
 Subclass IV. Heterologous union. 
 
 23. A Frog with a small additional anterior extremity springing 
 
 from the posterior and lateral part of the sternum. 
 
 This preparation has been placed provisionally in its present 
 position, under the theory that the limb in question is the only 
 developed part of a second embryo. Such is probably the case, 
 but there is too little evidence to justify any decided inference. 
 (See also Nos. 47 and 48.) 
 
 Hunterian. 
 
 Subseries IV. IN REPTILES. 
 
 Subclass I. Dichotomy*. 
 A. Anterior Dichotomy.. 
 
 Syn. Cephalodidymi, Gurlt. 
 
 Monstres doubles monosomiens, Geoff: 
 
 24. A small English Snake with two heads. The axis is di- 
 
 stinctly double to about half an inch behind the occipital 
 bone only, although there are traces of duplicity in the 
 ventral region more than an inch further back. 
 
 Hunterian. 
 
 25. A small Snake with two distinct heads and double vertebrae 
 
 in the anterior portion of the body. One head is slightly 
 lateral and smaller ; its neck is shorter than that of the 
 other. Hunterian. 
 
 26. A small Indian Water-Snake (Hydrophis) with two heads. 
 
 Presented by J. Shortt, M.D., 1866. 
 
 * See Introduction. 
 
6 ABNORMAL CONDITIONS OF THE AXIS. 
 
 27. A small English Snake with two heads. 
 
 Presented by W. White Cooper, Esq., 1872. 
 
 B. Posterior Dichotomy. 
 
 There is no true case of congenital posterior dichotomy in 
 Reptiles in the Collection. The following specimen probably 
 represents an acquired condition, the result of injury and the 
 well-known powers of repair possessed by these animals. 
 
 28. A Lizard in which a portion of the extremity of the tail is 
 
 double. Hunterian. 
 
 Subseries V. IN BIRDS, 
 
 Subclass I. Dichotomy. 
 
 A. Anterior Dichotomy. 
 
 29. A foetal Duck with two heads and necks ; the dorsal vertebrae, 
 
 the trunk, and its appendages are single. 
 
 Hunterian. 
 
 30. A similar foetal Turkey with the skull and vertebral canal 
 
 open from arrested closure of the neural arches, 
 
 Presented by Lady Northampton. 
 
 31. A similar fo3tal Fowl, in which the neural arches of the head 
 
 are undeveloped. The brain-membranes are exposed. 
 
 Presented by Sir W. Elizard. 
 
 32. A similar foetal Chick with fusion of the heads, so that the 
 
 approximate eyes have coalesced into a single organ. The 
 neural arches of the head are undeveloped, and the brains 
 are exposed. The spinal cord is deficient, the vertebral 
 canal containing its membranes only. . Hunterian. 
 
 B. Posterior Dichotomy. 
 
 33. A Chick with the posterior half of the cerebro-spinal axis 
 
 double. There are four legs, but the wings are two in 
 number. The abdominal parietes are deficient, and the 
 neural laminae are undeveloped in the cervical region. 
 There is a slight notch in the upper mandible, as if a 
 tendency to superior dichotomy had likewise existed. 
 
 Hunterian. 
 
 34. A Duckling with posterior dichotomy of the greater part of 
 
DUPLICITY. 7 
 
 the spinal column. There are four legs and wings. 
 The median wings are united into a single organ. 
 There is considerable deficiency in the coverings of the 
 abdomen. 
 
 35. The posterior part of a Duck affected with slight posterior di- 
 
 chotomy, laid open to show the pelves and their contents. 
 There are four perfect legs, although two only appear to 
 have been functional. The anus is double. That of 
 the right side is imperforate ; it forms a small nipple-like 
 projection externally, and is connected with the cloaca 
 by an imperforate band. The intestine has three caeca 
 instead of two. Presented by Mrs. Robinson, 1819. 
 
 36. The oviduct, rectum, and cloaca of a Fowl with two external 
 
 openings. The cloaca is bifurcated below. A single 
 oviduct opens into its left side. This specimen is pro- 
 bably from a bird affected similarly to the last but to a 
 less degree. Mr. Tegetmeier had a similar Fowl in which 
 both openings were functional. 
 
 Presented by Dr. Halford, 1862. 
 
 37. Posterior dichotomy of the spinal column in a Chick, with 
 
 fusion of the soft parts of the median pairs of legs as far 
 as the knee. Mus. Brit. 
 
 38. A similar Chick. Hunterian. 
 
 39. A Duckling in which there is posterior dichotomy of the 
 
 axis. The left division of the axis is rudimentary in com- 
 parison with the right, and the legs of the left side are 
 fused to the toes. There are two distinct femora and 
 seven digits ; the condition of the limb is similar to that 
 seen in No. 65. This specimen has been partially dis- 
 sected to show the connexion of the redundant limbs with 
 the spine. Mus. Brit. 
 
 40. A Chick with considerable posterior dichotomy of the axis,. 
 
 accompanied with total deficiency of the beak, mandible, 
 and tongue. The posterior nares are completely exposed. 
 The hyoid bone is not deficient. Unfortunately the tho- 
 racic and abdominal parietes have been removed, so that 
 it is impossible to discover how far they were defective. 
 
 41. Posterior dichotomy in a Duckling extending into the cer- 
 
 vical region, and perhaps involving the base of the skull. 
 The neural arch of the skull is open and the brain is 
 
8 ABNORMAL CONDITIONS OF THE AXIS. 
 
 exposed. The upper mandible and maxillary bones are 
 entirely deficient, but there is a slight frontal protu- 
 berance. Presented by D. Hanbury, Esq. 
 
 Subclass II. Homologous union. 
 a. Pleuropagus, Forster. 
 
 The following preparations exhibit posterior combined with 
 anterior dichotomy ; but there appear to be two axes throughout, 
 although the vertebrae are themselves fused in some part of the 
 spinal column. The condition will be at once understood by 
 comparing Nos. 118 to 121. It is impossible, as has already 
 been stated, to say whether the condition arises from fission or 
 fusion. 
 
 42. Twin foetal Pigeons united by the dorsal regions of the 
 
 spinal column, the median visceral laminae being absent. 
 The right lamina of one bird and the left of the other 
 form the abdominal and thoracic walls. The heads and 
 necks are distinct. The neural arches in the upper part 
 of both vertebral columns are defective. 
 
 Purchased, 1858. 
 
 43. Twin foetal Guinea-fowls similarly united with fusion 
 
 of the vertebral columns in their upper part. There is 
 also fusion of the head and necks. The median eyes are 
 fused into a single but abnormally large organ. The 
 lower mandibles likewise form a single organ. The neural 
 arch of the skull is open, and the brain and spinal cord 
 are deficient. Presented by E, Belfour, Esq. } 1818. 
 
 44. A similar union of twin foetal Ducks. The brain is com- 
 
 pletely double and without any covering. 
 
 b. Hypogastrodidymus, Gurlt. 
 
 The two succeeding specimens almost exhibit the characters of 
 heterologous union ; they, however, probably commenced their de- 
 velopment by homologous union, and have therefore been placed 
 in this Subclass. (See also Nos. 103 and 104, which present a 
 similar condition.) 
 
 45. A Chick with the rudiments of a second Chick occupying 
 
 the pubic symphysis. The rudimentary Chick consists 
 
DUPLICITY. 9 
 
 of a pelvis, with total deficiency of an axis, and of two 
 posterior limbs fused together above as far as the middle 
 of the femora by the skin and soft parts. Hunterian. 
 
 46. A Chick with the imperfect wings and legs of a second 
 Chick attached to the abdominal integuments. 
 
 Hunterian. 
 
 Subclass IV. Heterologous union. 
 
 47. A Duckling with the remains of a second embryo adhering 
 
 in the superior fontanelle, which has not been closed. 
 It consists of a kind of atheromatous tumour, partially oc- 
 cupied by a hernia of the Duckling's brain, with a small 
 but well-developed leg and foot growing from it. 
 
 Hunterian. 
 
 48. A Pigeon with a small accessory wing growing from the 
 
 lower part of the sternum. There is no other trace of a 
 second embryo, and the skin has been reflected to show 
 the union of the limb by muscles and ligament with the 
 sternum. Hunterian. 
 
 Comparing this specimen with No. 47, and in the complete ab- 
 sence of any other means of accounting for the condition, it has 
 been placed in this series, as it seems probable that the limb may 
 be the remains of a second embryo. (See also No. 23.) 
 
 Subseries VI. IN MAMMALS. 
 
 Subclass I. Dichotomy. 
 
 A. Anterior Dichotomy. 
 * In Animals. 
 
 Anterior dichotomy in Mammals rarely extends further back 
 than the basioccipital bone ; it occasionally, however, reaches the 
 dorsal vertebrae. In this respect Mammals present a marked 
 contrast to Birds and Reptiles, in which it usually involves some 
 of the vertebrae at least, It is very rare in the human subject. 
 
10 ABNORMAL CONDITIONS OF THE AXIS. 
 
 a. Diprosopus, Gurlt. 
 Syn. Monocranus, Gurlt. 
 
 Diprosopus is the term applied to those forms of anterior 
 dichotomy in which fission does not extend to any of the ver- 
 tebrae. This condition often accompanies posterior dichotomy. 
 Examples are seen in Nos. 90 to 94. In its lesser forms it is 
 called Monocranus by Gurlt. 
 
 49. A Kitten with dichotomy of the anterior part of the face ; 
 
 one mouth is very imperfect. There is a single pair of 
 eyes. Hunterian. 
 
 50. A Kitten with dichotomy of the head extending further back 
 
 than in the last, so that there are four eyes. The eyelids 
 of the median eyes have no inner commissures, but are 
 united and bound in a single fissure. Hunterian. 
 
 51. A foetal Kitten with more considerable anterior dichotomy. 
 
 The laminae of the vertebrae and spinal cord are deficient 
 in the lumbar region. Hunterian. 
 
 52. The head of a foetal Pig with dichotomy of the anterior part 
 
 of the face ; the mandible, tongue, and the anterior portion 
 of the maxillary bones are double. There is a consider- 
 able fissure in the palate, from which a fibrous band ex- 
 tends to the united mesial rami of the mandible. A por- 
 tion of skin covered with hair, representing the median 
 cheeks, is lodged in the fissure in the palate. 
 
 Hunterian. 
 
 53. The head of a foetal Pig with considerable dichotomy of the 
 
 lower, and slight dichotomy of the upper jaw, dissected to 
 show the accessory masseter muscles. The tongue is 
 double ; the other parts are single. This specimen before 
 dissection exhibited only what appeared to be a second 
 mouth in the cheek. 
 
 54. An anencephalous foetal Pig with more considerable anterior 
 
 dichotomy than the last, producing a single median eye. 
 
 Purchased. 
 
 55. The head of a Calf with anterior dichotomy extending as far 
 
 back as the presphenoid bone. The muzzles are united 
 by a thick fold of integument almost to their extremities. 
 
DUPLICITY. 11 
 
 There is a single median eye situated behind a triangular 
 opening formed by the fusion of two pair of eyelids. 
 
 Hunterian. 
 
 56. The skull of a similar Calf, in which the fission has extended 
 
 somewhat further back, so that there are two distinct 
 median orbits. The median malar bones are fused into 
 a single bone j they support a small mass of bone, which 
 articulates by a very imperfect joint with the median 
 rami of the mandibles. The median rami of the mandi- 
 bles are united by suture, and are much thickened and 
 distorted. The base of the skull exhibits a single basi- 
 occipital and a bifurcated basis phenoid with its two 
 median alisphenoids united. The exoccipitals, supraoc- 
 cipital, and temporals are single, except that there are 
 traces of median squamosals. The other bones of the 
 head and face are completely double. 
 
 57. A similar skull, in which, however, dichotomy extends as far 
 
 back as the basioccipital. In this skull there are two 
 supraoccipital and a median external auditory meatus; 
 the periotic bones of the median ear are double ; both 
 faces are distinct and well formed. Hunterian. 
 
 58. The brain of a Calf with anterior dichotomy, probably from 
 
 No. 55. All the parts in front of the pons are double. 
 The pons, medulla, and cerebellum are single. 
 
 Hunterian. 
 
 59. A portion of the brain of a Calf double as far back as the 
 
 foramen magnum, probably from the same animal as 
 No. 57. It is stated in Hunter's MS. dissections that 
 all the cerebral nerves were double, that the eighth pair 
 were double at their origin, but that the median eighth 
 pair became fused and terminated in their passage through 
 the skull in connective tissue. Hunterian. 
 
 60. A portion of the skull and the brain of the Sheep with di- 
 
 chotomy extending as far back as the basioccipital bone. 
 
 61. The tongues, hyoid bones, larynx, trachea, and oesophagus 
 
 of a double-faced Calf, probably from the same animal as 
 Nos. 55 and 58, dissected. The double hyoid arch has 
 its median cornua distinct, close together, and cartila- 
 ginous. The median pair of tonsils are seen fused to- 
 gether between the two tongues. It is stated in Hunter's 
 
12 ABNORMAL CONDITIONS OF THE AXIS. 
 
 MS. dissections that there was a third median carotid 
 in front of the trachea,, which divided in the head into 
 two vessels having the usual branches and distribution. 
 
 Hunterian. 
 
 b. Dicephalus, Gurlt. 
 
 In dicephalus the dichotomy extends beyond the base of the 
 skull, and involves the anterior portion of the vertebral column. 
 
 62. The cervical and some of the dorsal vertebrae of a dicephalous 
 
 Calf, in which dichotomy extends as far as the anterior 
 dorsal vertebrae. The atlas and axis of the right neck 
 are unfortunately lost. The dorsal spines below the di- 
 chotomous region are bifurcated. There are two ossinc 
 centres in the bodies of the dorsal vertebrae, a condition 
 seen- in almost all malformations of the spine. A num- 
 ber of small ossinc centres occur between the bodies of 
 the vertebrae at the point of bifurcation. There is a 
 piece of cartilage in the angle of bifurcation. 
 
 Presented by J. B. Stauffer, Esq., 1867. 
 
 63. The brains and a portion of the spinal cord of a dicephalous 
 
 Lamb. Dichotomy extends to an inch and a half below 
 the foramen magnum. 
 
 64. The oesophagus of a dicephalous (?) Lamb bifurcated to within 
 
 about 4 inches of the stomach. 
 
 Presented by R. Partridge, Esq. 
 
 B. Posterior Dichotomy. 
 
 * In Animals. (This condition is almost confined to quadrupeds, and is 
 very rare in the human fostus. Human foetuses affected with di- 
 chotomy have been placed together at the end of the series : see 
 Nos. 87, 88, and 89.) 
 
 a. Dipygus, Gurlt. 
 
 Dichotomy of the posterior portion of the axis is far more 
 common in Mammals than of the anterior portion. There are 
 three distinct forms of posterior dichotomy. In the first the 
 pelvis alone is double and the second axis is wanting ; hence it 
 is doubtful whether such forms should be included in this class. 
 
DUPLICITY. 13 
 
 It is probable, however, that the axis was originally dichoto- 
 mous, but that development of one portion is arrested at an early 
 stage. Another hypothesis is that the second pelvis originates 
 in the process of repair consequent on an injury to the embryo. 
 Valentin injured the posterior extremity of an embryo and pro- 
 duced this condition. It is impossible with our present know- 
 ledge of the subject to decide on the merits of these two hypo- 
 theses. Without Valentin's experiment analogy would lead us 
 to adopt the former view unreservedly. The term dipygus has 
 been restricted in this Catalogue to such forms. 
 
 65. The skeleton of a dipygous Kitten. 
 
 The axis deviates to the right side, and the laminae of the ver- 
 tebrae are deficient in the lumbar region. The right innominate 
 bone of the right axis and the left innominate bone of the left axis 
 are united by the pubic symphysis ; each bears a perfect limb. The 
 other innominate bones are rudimentary, and their ilia and aceta- 
 bula are fused together. The tuberosities of the ischia of these 
 median imperfect bones are ankylosed with those of the more 
 developed fellow bones. The left femur of the right axis and the 
 right femur of the left axis are fused into a single broad bone with 
 two heads ; this articulates with a single median tibia and two 
 fibulae. There are two perfect feet to this median limb. 
 
 66. A dipygous bitch Pup with the abdomen laid open to show 
 
 the viscera. 
 
 The innominate bones and additional posterior extremities are 
 precisely like those of No. 65. The rectum bifurcates about an 
 inch and a half from its extremity ; the right portion is blind. 
 The external sexual organs are double. There are two vaginae 
 and two bladders. The right bladder is smaller than the left. 
 The right kidney is very small ; its ureter becomes impervious about 
 a line from its inferior extremity, where it is connected with the 
 left vagina. The left kidney is very large ; its ureter opens into 
 the left bladder. A bristle points to the right kidney. The va- 
 ginae and anus are also marked with bristles. 
 
 Hunterian. 
 
 67. The external and internal generative organs and a portion 
 
 of the double pelvis of a large Dog, dissected. 
 
 There is no history of the preparation ; but it is probably from a 
 dipygous animal very similar to the last, except that the posterior 
 
14 ABNORMAL CONDITIONS OF THE AXIS. 
 
 innominate bones are less developed, so that the median leg was 
 probably either rudimentary or wanting. 
 
 The accessory innominate bones consist chiefly of the tuberosities 
 and posterior rami of the ischia ; these are united below by os- 
 sified fascia, which extends to the arch of the pubis. There are 
 two penes, urethree, and bladders, and but two testes. Each blad- 
 der has a single ureter opening into its outer side. The right 
 kidney is reduced to a hard fibrous button-shaped mass, about three 
 quarters of an inch in diameter ; the right bladder is much thinner 
 than the left, and its cavity is occupied by a fungous mass of 
 granulations. The muscles of the bulbs of the urethrae arise partly 
 from the additional and partly from the normal pelvic bones. The 
 right prostate is very small, and the urethra of this side is im- 
 pervious where it passes between the pelvic bones. 
 
 b. Schizorhachis. 
 
 Under this term all cases of posterior dichotomy of the spinal 
 column have been included, except those in which the mal- 
 formation extends to the head and appears externally, and 
 those already described as dipygus. Dichotomy almost always 
 extends to the occiput, and usually affects the basioccipital bone 
 slightly. A single preparation shows dichotomy of the lumbar 
 region only. 
 
 a. Unsymmetricdl Schizorhachis. 
 
 68. The posterior portion of a foetal Pig, with posterior dicho- 
 
 tomy of the spinal column commencing in the lumbar 
 region. The right half of the double axis and its limbs 
 are much smaller than the left. This preparation has 
 been dissected to show the viscera. 
 
 The intestine and stomach are drawn up. There are two uri- 
 nary bladders ; that belonging to the accessory axis has two ureters 
 and two minute kidneys. There is a large suprarenal capsule on 
 the right side. The left axis has only a single, much elongated 
 kidney on its left side. The aorta bifurcates to supply the second 
 axis. 
 
 /3. Symmetrical Schizorhachis. 
 
 69. A foetal Pig with dichotomy of the whole spinal column and 
 
 four distinct anterior extremities. The thoracic and ab- 
 dominal cavities have been opened to show the heart and 
 
DUPLICITY. 15 
 
 main arterial trunks. The heart consists of two left hearts 
 united ; there are no pulmonary hearts. Each ventricle 
 gives off an aorta which crosses to the opposite side, so 
 that the heart on the left side supplied the right inferior 
 extremities, and that on the right the left. The carotids, 
 two in number, are given off together from the arch of 
 the right aorta. The trachea is single. The lungs are 
 very small and imperfect ; they probably consist of a 
 single pair. The vessels of the right heart are injected. 
 The palate is deeply cleft. Hunterian. 
 
 70. A similar foetal Pig with the skull and spinal canals laid 
 
 open to show the brain and cords. The adjacent lateral 
 tracts terminate by joining each other, the outer ones 
 alone pass to the brain. Hunterian. 
 
 71. A similar but anencephalous foetal Pig. The base of the 
 
 skull is exposed ; the cerebral nerves are, however, quite 
 distinct at their point of exit from the skull. 
 
 Hunterian. 
 
 72. A foetal Mole with dichotomy of the whole spinal column. 
 
 Hunterian. 
 
 73. A foetal Puppy with dichotomy of the spinal column. The 
 
 median pair of anterior extremities are represented only 
 by a tubercle. It is probable that the dichotomy does 
 not extend into the upper part of the cervical region. 
 
 Hunterian. 
 
 74. A foetal Kitten with dichotomy of the axis and four complete 
 
 anterior extremities. Hunterian. 
 
 75. A similar Kitten. Hunterian. 
 
 76. The skeleton of a similar Kitten, in which the occiput is 
 
 slightly cleft, so that there are two exoccipitals. 
 
 This specimen belongs strictly to the following subdivision, 
 Schizocotis ; it is probable, however, that some of the preceding 
 specimens are similarly affected. It has therefore been thought 
 expedient to separate those forms only as Schizocotis in which the 
 cleft condition of the skull is apparent externally. These divisions 
 are not separated by any distinct lines of demarcation and are 
 purely artificial. The manner in which the median ribs are de- 
 pressed and united in animals affected with dichotomy is well seen 
 in this preparation. 
 
 Presented by J. Burton, Esq. 
 
16 ABNORMAL CONDITIONS OF THE AXIS. 
 
 77. A similar foetal Kitten, with the skull and spinal canal opened 
 
 to show the brain and the double medulla and cord. 
 
 Hunterian. 
 
 78. A similar Kitten, with the thorax and abdomen opened to 
 
 show the viscera. There is slight anterior dichotomy 
 affecting the lower lip, mandible, and tongue, with fis- 
 sure of the palate. The alimentary canal is double from 
 the lower portion of the ileum downwards. 
 
 Hunterian. 
 
 79. A similar Kitten, with the thorax and abdomen opened and 
 
 the viscera raised to show the kidneys, of which there 
 are but two, the urinary bladders, and hypogastric arteries. 
 
 Hunterian. 
 
 80. A similar Kitten, in which the median pair of anterior ex- 
 
 tremities are united as far as the carpus. The upper lip 
 and palate are deeply cleft. Hunterian. 
 
 c. Scliizocotis*. 
 
 Under this term those forms have been classed in which, in 
 addition to complete dichotomy of the trunk, dichotomy of the 
 posterior part of the skull is apparent externally. A pair of more 
 or less developed external ears exist between the two axes, exhi- 
 biting variable degrees of fusion with one another in a manner 
 analogous to that seen in extreme cases of anterior axial defi- 
 ciency. 
 
 81. A foetal Rabbit with slight dichotomy of the base of the 
 
 skull. The approximate external ears are of small size ; 
 they are very defective, and are fused together. 
 
 Hunterian. 
 
 82. A foatal Rabbit with somewhat more considerable dichotomy 
 
 of the base of the skull. There are a distinct pair of ad- 
 ditional ears. The roof of the skull has been removed 
 to show the extent of the dichotomy. This was one of 
 a litter of six, the remainder were normal. 
 
 Presented by C. R. Bree, M.D., 1871. 
 
 83. A foetal Cat with dichotomy extending to the base of the 
 
 skull, and involving only part of the basioccipital bone. 
 
 * Kom, the occiput. 
 
DUPLICITY. 17 
 
 The additional external ears are very defective and are 
 fused together. Hunterian. 
 
 84. A similar dichotomous foetal Pig. 
 
 
 
 d. Schizocephahis. * 
 
 Syn. Iniops, Geoff'. 
 
 Synkephalus asymmetros, Forster. 
 Janus -Bildung. 
 
 This condition depends, apparently, on an extension of pos- 
 terior dichotomy still further forwards, so that it involves the 
 greater part of the base of the skull. An accessory face is 
 formed in the angle between the two axes. This face is deficient 
 in its axial parts, and hence it exhibits the phenomena of axial 
 arrest or deficiency, as fusion of the eyes and ears, agnathia, &c. 
 (See Class VI.) 
 
 85. A foetal Pig with dichotomy of the axis extending forward 
 
 into the basisphenoid region. The accessory face has 
 the eyes fused together as far as the edges of their irides. 
 There is a frontal proboscis above, and a pair of closely 
 approximated ears below; a condition precisely similar 
 to that seen in cases of epencephalic deficiency, i . e. defi- 
 ciency of the epencephalic region and all the parts an- 
 terior to it. (See Nos. 187 to 190.) Hunterian. 
 
 86. A similar foetal Pig with the eyes of the accessory face di- 
 
 stinct, but so obliquely placed that the fissures of the 
 eyelids are almost vertical. 
 
 Presented by J. Winterbottom, Esq. 
 
 ** In the Human foetus. 
 a. Schizorhachis. 
 
 Syn. Dipygus, Forster. 
 Deradelphus, Geoff. 
 
 87. A female Human foetus with complete dichotomy of the spi- 
 
 nal column, probably affecting the basioccipital region, 
 although there is no external indication of dichotomy 
 extending to the skull. There are two perfect trunks 
 united by the thorax. One of the right arms is distorted 
 at the wrist. Hunterian. 
 
18 ABNORMAL CONDITIONS OF THE AXIS. 
 
 b. Schizocotis. 
 
 Syn. Synkephalus asymmetros, Forster. 
 Janiceps, Geoff. 
 Janus- Bildung. 
 
 88. A female Human foetus with posterior dichotomy extending 
 
 into the base of the skull, probably as far forward as the 
 posterior part of the basisphenoid. There is a pair of 
 well-formed external ears behind fused together below, 
 with a single meatus between them. A small circular fossa 
 above these, with a depression in its centre from which a 
 minute tuft of hair is growing, probably represents a 
 rudimentary Cyclops-eye. Mus. Brit. 
 
 89. A similar female Human foetus with the dichotomous condi- 
 
 tion extending a little further forwards, so that a trans- 
 verse fissure corresponds to the position of a Cyclops-eye. 
 Brought from the East Indies in 1805. 
 
 Presented by Sir E. Home, Bart., 1807. 
 
 C. Antero-posterior Dichotomy. 
 Syn. Hemipagus, Geoff. 
 
 Anterior and posterior dichotomy often coexist in the same 
 embryo. In animals there can be no doubt that this condition 
 is distinct from Homologous union', when it is extreme, how- 
 ever, as in No. 94, a human foetus, it is impossible to deter- 
 mine to which Subclass the phenomenon should be referred*. 
 
 90. A foetal Kitten with complete dichotomy of the trunk, and 
 
 a slightly double condition of the tongue and mandible. 
 
 Hunterian. 
 
 91. A similar foetal Kitten with more considerable dichotomy 
 
 of the mandible and tongue, accompanied by cleft palate. 
 
 92. A similar Kitten with the median anterior limbs fused as 
 
 far as the carpus. 
 
 93. A foetal Pig with posterior dichotomy (Schizorhachis) com- 
 
 bined with anterior dichotomy of the lower jaw and 
 tongue. There is a considerable cleft in the palate con- 
 nected with the median rami of the jaw by a fold of 
 mucous membrane. (No. 52 exhibits a similar condition.) 
 
 Hunterian. 
 * See Introduction. 
 
DUPLICITY. 19 
 
 94. A female Human foetus with posterior dichotomy (Schizo- 
 
 rhachis) combined with anterior dichotomy, producing 
 considerable doubling of the face. There are four eyes, 
 but the inner ones are contained in a single orbit. The 
 axes diverge, both in front and behind, from a point in the 
 basisphenoid bone. Hunterian. 
 
 Subclass II. Homologous union. 
 A. Prozygosis*. 
 
 Syn. Somatodidymus, Gurlt. 
 
 Monstres Syncephaliens, Geoff. 
 Synkephalus symmetros, Forster. 
 Janus-Bildung. 
 
 In Prozygosis there are two perfectly distinct axes united at 
 their anterior extremities, so that at an early stage there must 
 have been two distinct embryos. The foetuses arising from such 
 embryos are united by the visceral arches and laminae above the 
 umbilicus. The right side of one axis unites with the left side 
 of the opposite one. 
 
 95. Female Human twins, about the seventh month of gestation, 
 
 united by prozygosis. The faces are opposite to each other, 
 and at right angles to the normal position; they are 
 much flattened, the eyes are closely approximated, and 
 the ears are very low down. The two embryos were pro- 
 bably distinct at first, and became united by the fusion of 
 the anterior extremities of the investing mass of each with 
 that of the other, so that the trabeculse became united in 
 the same manner as the other facial arches are joined, 
 the right arch of one embryo being fused with the left 
 arch of the other. 
 
 The following history is recorded: "Labour lasted 
 forty-eight hours, delivery followed without instruments. 
 The mother, a negress, had convulsions. The foetuses 
 lived five minutes, a very unusual occurrence in such 
 cases. There was one funis and one placenta." 
 
 Presented by T. Sharp, M.D., 1820. 
 
 96. A similar twin-birth about the sixth month of gestation, 
 
 * Upo before, vyow to unite. 
 
 c 2 
 
20 ABNORMAL CONDITIONS OF THE AXIS. 
 
 except that the two faces are not perfectly symmetrical, 
 the mouth of one being a small circular opening. 
 
 Mus. Brit. 
 
 97. Twin foetal Hares united by the anterior extremities of the 
 
 axes. The anterior portion of each axis has been arrested 
 in development, so that the faces exhibit the characters 
 of epencephalic deficiency, cyclopia, agnathia, fusion of 
 the ears, &c. Presented by Sir W. Blizard, 1811. 
 
 98. Twin foetal Hares in a similar condition. There is a frontal 
 
 proboscis on one face. 
 
 B. Opisthozygosis*. 
 
 Syn. Hypogastrodidymus, Gurlt. 
 Ischiopagus, Geoff. 
 
 In Opisthozygosis two distinct axes are united at their posterior 
 extremities, or at some point near their posterior extremities. The 
 embryos remain completely separate above the umbilicus, but 
 unite below by the visceral laminae. One foetus is generally very 
 defective. Sometimes the axes are bent at right angles, in opposite 
 directions, at the point of union. Opisthozygosis is very rare in 
 animals, and the pelvic bones and posterior limbs only of the 
 second axis are usually developed in them, as in No. 103. A 
 similar condition in birds is seen in Nos. 45 and 46. 
 
 99. Human female twins united by Opisthozygosis about the 
 
 sixth month of gestation. The viscera had been re- 
 moved and the spinal columns and pelvis much damaged 
 by a hasty examination. The viscera were fortunately 
 preserved, and are seen in No. 100, 
 
 The sacrum of one side only has been developed. It is 
 situated at right angles to the two spinal columns, which 
 are placed end to end, the bodies of the vertebrae being 
 united without any perceptible break. The sacrum is 
 entirely cartilaginous, no traces of the second sacrum 
 exist. The pelves are otherwise perfect ; but the right in- 
 nominate bone of one foetus is united with the left in- 
 nominate bone of the other, and vice versa. The ilia are 
 united to the lumbar vertebras by elongated transverse 
 
 behind, wy6a> to unite. 
 
DUPLICITY. 21 
 
 processes. The upper pair of limbs (in the present posi- 
 tion of the preparation) belong to the upper and the lower 
 pair to the lower foetus. Each foetus may be considered 
 as having its pubic symphysis open and its pubic bones 
 united with those of the other. The axial parts posterior 
 to the point of union in the upper foetus turn to the right, 
 those of the lower to the left side of the preparation. 
 
 The upper foetus is well formed, except in the pelvic 
 region. The lower foetus is very imperfect. Its face is 
 misshapen, and the upper cranial bones are altogether 
 wanting. The superior extremities are thick and defec- 
 tive, and the fingers are very short, owing to the imperfect 
 condition of the terminal phalanges. The nails are 
 scarcely perceptible. No history has been preserved. 
 100. The viscera and generative organs of the same. The viscera 
 of the upper foetus are seen upon the right hand, those of 
 the lower upon the left-hand side of the preparation. 
 
 The heart, liver, and lungs of the upper foetus are nor- 
 mal : the development of the intestines seems to have been 
 somewhat arrested ; they terminate in a very capacious 
 thin-walled rectum, which was much stained with me- 
 conium. There is a small anal opening marked by a 
 white bristle; it is probable, however, that the dilation 
 of the rectum arose from atresia at an earlier stage. 
 
 The heart, lungs, and liver of the lower foetus are much 
 smaller ; the intestines are about equal in development to 
 those of the upper one; there is much less enlargement 
 of the lower part of the bowel, but it opens into the en- 
 larged intestine of the upper foetus near the anal opening. 
 The most remarkable character in these viscera is that 
 they do not exhibit " situs mutatus." The kidneys in 
 both foetuses exhibit the condition known as horseshoe 
 kidneys ; they unite below with their fellows across the 
 mesial line. The four ureters open into a single large 
 urinary bladder, which is laid open ; the openings of the 
 ureters are marked by black bristles. The urethra is 
 likewise laid open. The uteri are both equally developed ; 
 both vaginae are well formed, but they both open with 
 the urethra on the right (upperside in this preparation) ; 
 their openings arc marked with black bristles. The labia 
 niajoru, ininora, and clitoris arc well formed on this side. 
 
22 ABNORMAL CONDITIONS OF THE AXIS. 
 
 The external generative organs of the other side are 
 very ill-formed, and are only connected with the internal 
 organs by the right round ligament of the uterus of the 
 lower foetus. There is no indication of either urethra, 
 vagina, or anus on this side. There is a small swelling, 
 about as large as a pea, at the anterior extremity of the 
 left labium. 
 
 101. Human female twins, about the sixth month of gestation, 
 united by opisthozygosis. The second foetus is exces- 
 sively malformed, and possesses neither heart nor brain. 
 
 The axes are united near the lower part of the dorsal 
 vertebrae by ordinary intervertebral cartilage and liga- 
 ments, exactly like those between the consecutive verte- 
 brae. The remainder of both vertebral columns is want- 
 ing as far as the sacral vertebras. There is a large sacrum 
 on the left side, placed at right angles to and behind the 
 united vertebral columns. The sacrum on the right side 
 is very defective, consisting of a mere ring of bone articu- 
 lated with the base of the left sacrum by cartilage and 
 ligament. 
 
 The neural arches of the vertebrae are open behind at 
 the point of union between the sacra and vertebral 
 columns. The laminae of both columns form a conti- 
 nuous series with those on the adjacent sides of the sacrum 
 on the left side, and of the rudimentary sacrum on the 
 right ; a large lozenge-shaped opening is thus left in the 
 neural canal. 
 
 The neural canal of the sacrum is continuous with that 
 of the vertebrae, and this makes a sharp bend backwards 
 from either axis to meet the sacral neural canal. 
 
 The following facts were recorded by Drs. Marcet, 
 Roget, and Mr. Lawrence from an examination made 
 when the foetus first arrived in England : " The inter- 
 val between the lamina of the vertebra was occupied by 
 a strong membrane ; on the division of this, the medulla 
 spinalis was seen running across from one spine to the 
 other, and distributing its nerves laterally to the two 
 lateral pelves/' 
 
 From a careful consideration of the above conditions, it appears 
 that the axes of two embryos came into contact at a very early 
 period of development, so that the neural cords arid the proto- 
 
DUPLICITY. 23 
 
 vertebrae in the dorsal regions were developed in a continuous 
 series ; and the caudal extremities of the axes became displaced 
 and partially absorbed, so that the axial portion of the sacrum 
 has been developed from the remains of one of these displaced axes. 
 The neural arches appear to have followed the same law of deve- 
 lopment as the visceral arches at the point of union between the 
 foetuses, those of the one axis tending to unite with those of the 
 other instead of with their fellows. 
 
 A comparison with other specimens of a similar malformation 
 renders its probable that the upper pair of legs and the correspond- 
 ing pelvic bones were developed from the visceral laminae of the 
 upper, and the lower pair from those of the lower foetus. 
 
 The thoracic viscera of the upper foetus are normal. The aorta 
 in the abdomen turns off to the left pelvis and gives off a pair of 
 large hypogastric arteries, of which the upper is the larger. At 
 the point where the aorta turns off to the left it gives origin to two 
 large vessels : one runs straight into the thorax of the lower foetus 
 and terminates in two innominate arteries, the other supplies the 
 right pelvis and lower limbs. 
 
 The whole of the anterior walls of both foetuses are extremely de- 
 fective. The ribs of the lower foetus are developed behind only. A 
 slip of muscle crosses its body -cavity from tjie left axilla to the right 
 pubis. Its thorax was chiefly occupied by a large sac, the greater part 
 of which has been removed with the viscera, and is seen in the next 
 preparation. This sac communicated with the intestines above and 
 with the mouth below. It is referred to in M. Maunoir's original 
 description of this monster (Med.-Chir. Trans, vol. vii. p. 257) as a 
 " kind of cloaca," of which he says, " On opening the cloaca it was 
 found to contain the rudiments of a lower jaw and of a tongue, which 
 were immersed in meconium, with which the cavity was filled." 
 The cranial and facial bones are only represented, in the inferior 
 head, by irregular masses of cartilage. There is a very rudimen- 
 tary and misshapen external ear. The brain was represented by a 
 large cyst filled with blood, a condition usual in anencephalic con- 
 ditions : this was removed before the foetus was sent to England. 
 
 The following history is recorded (Med.-Chir. Trans. I.e.}: 
 " A girl of 16 or 17 gave birth to this foetus in Geneva ; it lived 
 a few minutes. There was no difficulty in the labour ; the perfect 
 head was born last." 
 
 Presented by the Medico- Chirurgical Society, 1816. 
 
 102. The abdominal viscera of the same, except the liver, and 
 the kidneys which were contained in the left pelvic por- 
 tion of the twin-birth ; these parts had been removed. 
 
24 ABNORMAL CONDITIONS OF THE AXIS. 
 
 The following viscera are seen in this preparation : The stomach 
 of the superior foetus is displayed at the upper part of the mica, 
 with the duodenum, the remains of the liver, the jejunum, and 
 ileura. Near the middle of the latter, and connected with it by 
 about three quarters of an inch of intestine, is a portion of the large 
 cloacal sac from the inferior foetus. 
 
 The accompanying description of the liver occurs in M. Maunoir's 
 paper (I.e.): " An enormous liver covers the whole intestinal mass, 
 and appears through the transparent membranous abdominal wall, 
 between the laminae of which a single umbilical cord [probably 
 the umbilical vein only is here alluded to] passes in a serpentine 
 course and enters the liver." The liver, anterior abdominal wall, 
 and cord have unfortunately not been preserved. 
 
 The ileum bifurcates about an inch from its inferior extremity 
 and opens into two distinct caeca, each having a short vermiform 
 appendix. The large intestines are double : that on the right 
 side of the preparation belongs to the right side of the monster ; 
 it is opened to show its blind termination above the uterus. The 
 left large intestine belonged to the left inferior portion ; it termi- 
 nates in an anus. 
 
 The kidneys of the right side are preserved ; they are adherent 
 throughout their entire length. The left kidneys are wanting, but 
 are stated to have had but one ureter between them. The blad- 
 ders, urethras, and external sexual organs on both sides are normal. 
 There is a uterus on each side, the right one being considerably 
 larger than the normal foetal uterus. 
 
 Presented by the Medico- Chirurgical Society. 
 
 103. The skeleton of a half-grown female Cat, with an imperfect 
 
 accessory pair of innominate bones occupying the pubic 
 symphysisj an accessory pair of limbs are attached to 
 them. 
 
 Although the axial parts of this pelvis and all the remainder of 
 a second animal are absent, there can be little doubt but that these 
 bones were developed from a second embryo. If the axis had been 
 developed an opisthozygous twin monster would have resulted. 
 
 The second pair of limbs are short, distorted, and ankylosed to 
 the pelvis, probably from disuse. Their patellae are absent. 
 
 The Cat was caught in a trap in a wood, where it had been living 
 in a wild state. 
 
 Presented by W. B. Tegetmeier, Esq.., 1867. 
 
 104. The bones of the pelvis and inferior extremities of a Sheep, 
 
 with the pelvic bones and posterior extremities of an im- 
 
DUPLICITY. 25 
 
 perfect twin similarly attached. In this preparation the 
 parasitic limbs are fused as far as the metatarsus. A 
 comparison of these limbs- with the dichotomous limb of 
 a monkey, No. 307, shows the difference between malfor- 
 mation from fission and fusion in a marked manner. 
 
 Hunterian. 
 C. Parazygosis*. 
 
 In Parazygosis twins are united, by the visceral laminse of the 
 trunk, above the umbilicus. They are usually placed face to 
 face, and have the laminse on each side equally developed ; rarely 
 they are placed side by side, and have the laminae of the adjacent 
 sides very deficient. Parazygosis is extremely rare in animals, 
 although it is the commonest form of duplicity in the human 
 
 foetus. 
 
 a. Xiphopagus, Geoff. 
 
 The least degree of parazygosis. The union is by the xiphoid 
 cartilages of the sterna and by the abdominal walls, above the 
 umbilicus. 
 
 105. A wax model of the band of union of the " Siamese Twins " 
 
 made in 1830, when they were 19 years of age. In child- 
 hood the band was proportionately much larger and shorter, 
 so that the twins were much closer together. The xiphoid 
 cartilages of the sterna pass across the upper edge of the 
 band. The condition of these twins at the age of 19 and 
 their history is given in the Phil. Trans. 1830, p. 117. 
 
 Presented by G. B. Bolton, Esq., 1830. 
 
 b. Thomcopagus, Forster. 
 Syn. Sternopagus, Geoff. 
 
 In this form the thoracic cavities are united by the visceral 
 laminse ; the foetuses are placed symmetrically face to face. 
 
 106. Female Human thoracopagous twins, 3 inches long (about 
 
 the third month of gestation) . 
 
 Presented by Sir E. Home, Bart., 1804. 
 
 107. A similar twin-birth, 3 inches long (about the third month 
 
 of gestation) . 
 
 The relation of the foetuses was disturbed when this specimen 
 was first put into spirit, so that it docs not apparently conform with 
 
 by the side of, ?vy6w to unite. 
 
26 ABNORMAL CONDITIONS OF THE AXIS. 
 
 the above description of thoracopagus. Naturally the foetuses would 
 
 face each other in this and in the preparations Nos. 109 and 110. 
 
 Presented by W. Parry, M.D., 1870. 
 
 108. A Human female thoracopagous twin-birth, 8 inches long 
 
 (probably about the end of the fourth month of gesta- 
 tion). Presented by Sir PF. Blizard, Bart., 1811. 
 
 109. A Human female thoracopagous twin-birth, about 10 \ inches 
 
 long (probably at the end of the fifth month) . 
 
 Presented by Sir Joseph Banks, Bart., 1819. 
 
 110. A Human female thoracopagous twin-birth, about 12 inches 
 
 long (about the end of the sixth month of gestation) . 
 
 Hunterian. 
 
 111. Human female thoracopagous twins about full time of ges- 
 
 tation. The deficiency of the anterior abdominal wall 
 above the umbilicus is very considerable, the viscera being 
 covered by membrane only. Hunterian. 
 
 112. A similar twin-birth, with the visceral cavities laid open to 
 
 show the disposition of the viscera. The diaphragmata 
 and pericardia are united. The hearts are quite distinct. 
 The livers are completely fused: there are, however, 
 two transverse fissures and two ductse venosse. The in- 
 testines of the two communicate by a short capacious 
 gut near the lower part of the ileum. The single cord 
 has been laid open, and is seen to contain two distinct 
 umbilical veins (injected) and five umbilical arteries, one 
 foetus having a small additional one. TKe foetus on the 
 left-hand side of the preparation has the disposition of 
 the viscera reversed. 
 
 The following is the history of the birth : The first foetus pre- 
 sented by the face and the head was not expelled until about four 
 and twenty hours after the commencement of labour ; the abdomen 
 of the second child was then discovered. The feet of the first and 
 afterwards those of the second child were then brought down, and 
 so the mother was delivered, but not without considerable difficulty. 
 
 In five labours this woman had malformed births three times, 
 these twins, a child with the feet growing from the nates, and a 
 child with undeveloped forearms, so that the hands appeared as if 
 growing from the extremity of the humerus ; all were still-born. 
 The above particulars are extracted from a letter from Mr. G. W. 
 Friend to the Curator of the Hunterian Museum. 
 
 Presented by G. W. Friend, Esq., 1815. 
 
DUPLICITY. 27 
 
 113. Human thoracopagous twins of small size, with the viscera 
 
 removed to show the union of the thoracic and abdominal 
 parietes from within. The disposition of the ribs is well 
 seen in this preparation. 
 
 114. The heart and lungs of the same. 
 
 The heart is formed of the united hearts of both 
 foetuses ; it is much elongated in the direction of a line 
 joining the two spinal columns. There are two di- 
 stinct ventricles, and a single auricle extending the whole 
 length of the upper part of the ventricles. There is a 
 rudimentary auricular septum. There are two auriculo- 
 ventricular openings, each guarded by a bicuspid valve. 
 
 The cavities of the heart have been laid open. The ventricle on 
 the right-hand side of the preparation has two arterial openings at 
 its base, an aorta and a pulmonary artery, the latter indicated by a 
 blue glass rod. The ventricle on the left-hand side has a single 
 artery or aorta, -which gives off three pulmonary arteries near 
 its origin. This vessel is laid open to show the orifices of the 
 pulmonary vessels. There are four lungs, two on each side of the 
 preparation. Neither set exhibits situs mutatus. 
 
 115. The livers, stomachs, and duodena of the same. The livers 
 
 are united along their whole anterior edges. The sto- 
 machs and spleens are seen one on either side of the liver. 
 The gall-bladder and the ducts of each liver are distinct. 
 The duodena open into a common pouch just below the 
 entrance of the gall-ducts. The intestine was single from 
 the confluence of the duodena to the termination of the 
 jejunum. 
 
 116. The lower portion of the small and the commencement of 
 
 the large intestine of the same. The jejunum terminates 
 in a large pouch, on the extreme left of the preparation, 
 from which two ilea arise. There are two caeca, and each 
 has a distinct vermiform appendix. The large intestine 
 was completely double. 
 
 117. Human female thoracopagous twins about the end of the 
 
 sixth month of gestation. One of the foetuses has syreni- 
 form fusion of the posterior limbs, and there is complete 
 ectopia of all the abdominal viscera. The thoracic cavities 
 have been opened to show the hearts, which are very ab- 
 normal ; one is above the other. The upper heart consists 
 
28 ABNORMAL CONDITIONS OF THE AXIS. 
 
 of an auricle and ventricle. The ventricle gives an aorta 
 to either foetus, and is fused with the base of the ventricle 
 of the lower heart. The lower heart has two auricles. 
 The apices of both ventricles are turned towards the front 
 of the preparation. . The specimen was so brittle that the 
 exact distribution of the vessels could not be made out. 
 
 c. Pleuropagus, Forster. 
 
 Syn. Dicephalus, Gurlt. 
 
 Monstres doubles Sysomiens, Geoff. 
 
 In Pleuropagus two axes are adherent side by side. Such ab- 
 normal twins have hitherto been called dicephalus, from their 
 external resemblance to dichotomous conditions of the anterior 
 extremity of the axis. In these forms, however, the whole axis 
 is double. They are transitional between anterior dichotomy 
 and parazygosis. The median limbs are frequently fused toge- 
 ther, and are sometimes reduced to mere tubercles. 
 
 118. A Human pleuropagous twin-birth, about the end of the third 
 
 month (length 4| inches), with the mesial (posterior) arms 
 and legs fused together as far as the carpus and tarsus. 
 It is apparently female, but the organs of generation are 
 very imperfectly formed. This specimen is transitional 
 between thoracopagus and the more marked forms of 
 pleuropagus. Purchased, 1870. 
 
 119. Human male pleuropagous twins. The median (posterior) 
 
 arms form a mei*e tubercle upon the back. There are no 
 median legs, although there are two axes even to the ex- 
 tremity of the sacrum. The median innominate bones 
 are absent. 
 
 120. The bones and ligaments of the united mesial arms of an 
 
 exactly similar foetus. 
 
 A small portion of the broad sternum, formed by the 
 union of two sterna, supports a pair of clavicles closely 
 pressed together; distinct and flattened in front, but 
 united behind. These articulate with the two acromia of 
 a very remarkable double scapula, and are also united 
 with the glenoid cavity by ligament, a piece of cartilage 
 intervening. The scapula is symmetrical, and presents 
 two spines and two acromia ; one of the latter has been 
 cut through and turned back to show the manner in which 
 
DUPLICITY. 29 
 
 the glenoid cavity is articulated with the clavicles. The 
 cartilage already mentioned, situated between the clavicles 
 and glenoid cavity, is the only rudiment representing 
 the anterior median limbs. 
 
 121. The viscera of the same; these are double, but those of 
 
 the right foetus are considerably smaller than those of 
 the left ; the latter are reversed. The hearts were situ- 
 ated in distinct pericardia. The heart of the left is 
 three times the size of that of the right foetus. The latter 
 gives off a small aorta, which joins the descending aorta 
 of the left foetus just below its arch. The livers are in- 
 timately united ; the oesophagi, stomachs, and duodena are 
 distinct as far as the orifice of the bile-duct, where the 
 intestines unite in a sacculate dilatation ; below this point 
 the intestine is single but reversed, the caecum being on 
 the left side. 
 
 d. Ischiopagus, Forster. 
 
 Syn. Pygodidymus, Gurlt. 
 Pygopagus, Geoff. 
 
 In Ischiopagus the twins are united by the lower extremity 
 of the axis only, and are placed back to back, so that the visceral 
 cavities are distinct. Judith and Helena, " The Hungarian Sis- 
 ters " (Phil. Trans, vol. 50, p. 31 1) , and Millie-Christine, the "Two- 
 Headed Nightingale," exhibited in London in 1871 (Lancet, 
 1871, i. p. 725), are examples. No specimen occurs in the 
 Museum. 
 
 122. A wooden model representing two ischiopagous infants. 
 
 The anus is represented as single, and the vaginae are united at 
 their posterior commissures, the usual disposition of these parts 
 in such malformations. 
 
 Subclass III. Homologous union with dichotomy. 
 
 The so-called triplex human foetus described in the ' Atti delP 
 Accadem. Gioen. 5 t. viii. p. 203, is undoubtedly an example of 
 pleuropagus combined with anterior dichotomy of one axis. 
 Several cases are recorded by Gurlt as having occurred in 
 animals. 
 
30 ABNORMAL CONDITIONS OF THE AXIS. 
 
 Subclass IV. Heterologous union. 
 
 A. By Impaction. 
 Syn. Heterodidymus, Gurlt. 
 
 A second embryo may become wedged in between the visceral 
 arches or laminae of another before they unite. In such cases 
 the impacted foetus usually exhibits great deficiency,, and is called 
 a parasite. Most frequently it has neither a heart nor a head ; 
 sometimes it becomes converted into a more or less amorphous 
 tumour, with one or two organs only developed in a normal 
 manner. The supporting foetus is called the autosite. 
 
 a. Between the lateral halves of the sternum. 
 Syn. Thoracopagus Heterodelphus, Geoff. 
 
 The upper part of the parasite is wedged in between the thoracic 
 laminae of the autosite., and lodged in the middle of a fissured ster- 
 num. The parasite is usually very defective j the axis may be en- 
 tirely wanting, the limbs only being developed. More frequently 
 there is a rudimentary abdominal cavity in the parasite, commu- 
 nicating with that of the autosite above the umbilicus, as in ordi- 
 nary thoracopagus. The abdominal cavity of the parasite is some- 
 times distinct from that of the autosite, and has a separate um- 
 bilicus. A perfect series of transitional forms exist between this 
 condition and ordinary thoracopagus ; hence it has been called 
 parasitic, or heterodelphous thoracopagus. 
 
 123. A female foetal Pig with a headless acardiac parasite united 
 
 to the thorax and abdomen. The cervical region of the 
 parasite is attached to the sternum of the autosite. The 
 body-cavities of the two are continuous. The parasite 
 has a single large kidney, a urinary bladder, and a pair 
 of hypogastric arteries. There is also a small piece of 
 intestine connected with that of the autosite by a long, 
 narrow gut. The abdominal cavities have been laid open 
 to show their continuity. Hunterian. 
 
 124. A foetal Kitten with a similar parasite. Hunterian. 
 
 125. A foetal Kitten with a parasite attached to the sternal region. 
 
 The body-cavity of the parasite is very small and distinct 
 from that of the autosite. There are two distinct cords 
 
DUPLICITY. 31 
 
 for a short distance at least from the umbilicus. The 
 parasite appears to have no spinal column ; but the pos- 
 terior limbs are well developed, and the anterior limbs 
 are small but clearly recognizable. 
 
 Presented by E. Self our, Esq. 
 
 126. A similar specimen, in which the anterior extremities of the 
 
 parasite are fused with the left anterior extremity of the 
 autosite. 
 
 127. A similar specimen, except that the anterior extremities of 
 
 the parasite are wanting. 
 
 128. A specimen similar to No. 125, with the body-cavities laid 
 
 open to show that they are quite distinct. That of the 
 parasite contains a single large kidney and a urinary blad- 
 der : it has no alimentary canal. Hunterian. 
 
 129. The skeleton of a similar Kitten and parasite. The ster- 
 
 num of the autosite is divided by a wide oval fissure, 
 in which the four limbs of the parasite are seen. The pa- 
 rasite has no vestige of an axis, unless a band of ligament 
 in the centre of the sternal fissure represent its remains. 
 The anterior pair of parasitic limbs are fused as far as the 
 carpus. The Kitten was one of a litter of three, the 
 others were normal. 
 
 130. A clay model of the Chinese lad Ake, aged 16, with an 
 
 acephalous parasite attached to the lower part of the ster- 
 num. The model was made from memory by a Chinese 
 artist. The following extracts from a letter from J. Li- 
 vingstone, Esq., Surgeon to the British factory at Hong 
 Kong in 1804, give the history of the case : 
 " Ake was born with another male child of nearly the same size 
 united to the pit of his stomach by the neck, as if his brother had 
 plunged its head into his breast. The mother died from the effects 
 of the labour. 
 
 " Since birth the parasite has not increased much in size. 
 The shoulder-bones are remarkably prominent. Here the model 
 is faulty, since it presents the roundness of infancy ; but all the 
 plumpness had disappeared from the original, and the bones 
 seem only covered with skin. The manner in which the thighs 
 appear is quite happy; but the feet, particularly the left, are not 
 sufficiently clubbed. In the original the feet and toes are less 
 perfect than in the model ; the toes adhere, and one or two are 
 wanting. 
 
32 ABNORMAL CONDITIONS OF THE AXIS. 
 
 " I have the authority of Lieut.-General Wood for stating that 
 the trunk and neck measure 11 inches, and the longest limb 13 
 inches. 
 
 " The attachment of the neck of the parasite admits of a semi- 
 rotatory motion, and Ake shows that his brother's arms can bo 
 moved freely. The thighs and legs remain stiffly bent, the femora 
 being ankylosed to the innominate bones and tibia. The genital 
 organs are too perfect in the model, since no vestige of testes and 
 very little scrotum can be seen in the original. The penis is, how- 
 ever, large in proportion, with the glans about half covered by the 
 prepuce ; it was subject to occasional erections. The kidneys seem 
 to perform their function perfectly ; the anus is wanting. Ake is 
 now about 4 feet 10 inches high, of feeble frame and sickly ap- 
 pearance. Except in the incumbrance above described, he is in all 
 respects perfectly formed. Ake's respiration is commonly labo- 
 rious ; to relieve it, he frequently supports the parasite with his 
 hands; his pulse is commonly quick and small. Mr. Gomez 
 felt the pulsation of the carotids in the neck of the parasite di- 
 stinctly ; he also felt feeble pulsation at the wrists." 
 
 The condition of Ake, as far as can be judged from the model, 
 seems precisely the same as that of the Kittens, Nos. 124 to 128. 
 Presented by H. L. Thomas, Esq., 18.22. 
 
 b. Impaction between the facial arches. 
 
 In such cases the palate is most frequently the seat of impac- 
 tion, and the parasite is modified excessively. 
 
 131. The injected head of a Human foetus with a large lobulated 
 vascular tumour, the remains of a second foetus, growing 
 from the median fissure of the palate, which has been 
 kept open by it. The tumour projects from the mouth, 
 which it dilates considerably. It is adherent to the right 
 commissure of the lips, and entirely invested the superior 
 maxillary bone of the foetus, which has been removed and 
 is seen in No. 133. 
 
 The lobulated tumour presents a widely extended mouth in front. 
 A piece of purple glass rod is placed in its cavity, extending be- 
 tween the commissures of its lips. A long tongue- shaped projec- 
 tion is seen in the mouth-cavity ; but it is covered with lanugo, so 
 that it does not probably represent the tongue. The lips and 
 alveoli are very distinct ; they are divided into two lateral por- 
 tions by large lobules of fatty tumour. A single nostril, marked 
 by a blue glass rod, appears above the left half of the upper lip ; 
 
DUPLICITY. 33 
 
 at the inner side of the nostril is a deep fissure, probably the re- 
 mains of the nasal cavity ; this fissure is marked by a purple glass 
 rod. The left upper alveolus has been exposed by the removal 
 of the giim, and is very distinct. 
 
 One of the largest of the fatty lobes, which make up the bulk 
 of the tumour, has been cut through to show its structure. It 
 consists of firm vascular fat with an atheromatous centre. A 
 small cyst appears at its upper part. On the right side there is a 
 piece of adherent placenta, and just below it is a loose, pendent, 
 lobulated mass about an inch and a half in diameter. As one of 
 its lobes felt very hard it was opened, and was found to contain a 
 compact mass of bones, fifty-nine in number (see No. 132). The 
 skin of the tumour is soft, vascular, and covered with lanugo. The 
 lobe which contained the bones presents three indistinctly separate 
 hard white papilla?, something like aborted digits. 
 
 The most remarkable point in this specimen is that lips and 
 alveoli only are well developed upon the tumour, as if its position 
 had determined the nature of the part developed. There can be 
 no reasonable doubt that the tumour consists of the remains of a 
 second embryo. 
 
 132. Fifty-nine ossicles from the tumour in the last preparation. 
 
 They are most complex in form, and were closely packed 
 together. There is but one which resembles any normal 
 bone, the first of the series ; it appears like the lamina of 
 one of the cervical vertebrae. 
 
 133. The superior maxillary bone and a portion of the malar 
 
 bone from the same, taken from the right side of the 
 tumour. These belonged to the foetus and not to the pa- 
 rasite growth. It is normal, although it supported a por- 
 tion of the tumour. 
 
 B. By Inclusion. 
 
 Syn. Cryptodidymus, Ourlt. 
 Fo3tus in Fcetu. 
 
 Sometimes instead of a second embryo becoming impacted in 
 the visceral arches of another, it becomes enclosed within its ab- 
 dominal cavity. The included embryo in. these cases is contained 
 in a cyst, and connected with it by an imperfect funis. Under 
 these circumstances it may live and grow for many years. It 
 is always excessively defective and much deformed. Both the 
 including subject and fostus arc usually male. 
 
34 ABNORMAL CONDITIONS OF THE AXIS. 
 
 It is probable that such included foetuses owe their origin to 
 very nearly the same conditions as those which give rise to other 
 forms of doubling. It is not easy to understand how a second 
 ovum could enter the body-cavity of an embryo, whilst there is 
 no difficulty in understanding how a second embryo on a common 
 yelk could be so included. The cyst under such circumstances 
 would owe its origin to a portion of the common amniotic sac, 
 which the included embryo must necessarily carry before it. It 
 is true no connexion has been observed between the cyst and the 
 umbilicus ; but all things considered, the above is the least impro- 
 bable means of accounting for the phenomenon. The disappear- 
 ance of a portion of the amnion in several years is by no means 
 inexplicable, especially when it is remembered that the membrane 
 must have been extremely thin at the time of its induplication. 
 
 134. A portion of a cyst (which contained the foetus No. 135) 
 
 from the abdomen of a well-formed male child aged be- 
 tween 9 and 10 months. The preparation includes a por- 
 tion of large and small intestine of the child. 
 The case is described by Mr. Gr. W. Young in the ' Med.-Chir. 
 Trans.' vol. i. p. 234. The cyst is recorded to have contained 78 
 ounces of fluid, and to have discharged a portion of its contents 
 several times into the peritoneal cavity ; it is further stated to 
 have been placed between the layers of the transverse mesocolon. 
 The same thing was also believed in M. Duptiytren's case*; but 
 much difficulty arises in the explanation of the phenomenon if such 
 really be the fact. In the present instance it will be seen that 
 the mesentery is likewise adherent to the cyst, and the whole mass 
 is so matted together that it would be impossible to determine 
 whether the cyst is between the layers of the mesocolon or not ; it 
 is much more probable that the cyst was originally placed between 
 the mesocolon and mesentery. The portion of the cyst which has 
 been preserved consists of a number of layers, a fact quite in 
 consonance with the opinion that it was originally formed by an 
 induplication of the amniotic sac. It is very thick, and presents 
 a villous surface within. The upper part of the cyst, which was 
 covered by the omentum, has not been preserved. It is stated to 
 have been very thin and transparent. 
 
 Presented by G. W. Young, Esq. 
 
 135. The imperfect foetus from the same, divided vertically to 
 * Bulletin de la Soc. de la Facultc de Med. Paris, an 13,no. 1, p. 4. 
 
 Himly, Foetus in Fretn, p. 18. 
 
DUPLICITY. 35 
 
 show its internal structure. It has no head, its trunk is 
 very much curved, and possesses four misshapen limbs. It 
 was connected with the cyst by a large funnel-shaped 
 umbilical cord, which contains a coil of intestine. 
 
 Mr. Young states that " when the foetus was taken from the 
 cyst it was covered with sebaceous matter, and when this was re- 
 moved, it appeared as rosy and healthy as if it were alive." At 
 the upper extremity of the trunk a fibrous mass is seen with a 
 portion of the cyst adherent to it ; this is said by Mr. Young to 
 have been " of a dark-red colour when first taken from the cyst, 
 and abundantly supplied with blood." It is exactly similar to the 
 mass usually representing the brain in anencephalous foetuses. That 
 part of the foetus which, corresponds to the frontal region bears a 
 narrow line of fine hair upon it ; this forms a long lock on either 
 side. The vertebral column consists of eleven blocks of bone, re- 
 presenting as many vertebral centres. The posterior aspect of 
 these is covered by a membrane ; there are no remains of the 
 spinal cord, and no traces of laminse. The skin on either side of 
 the vertebrae is covered with short fine black hairs. The sacrum 
 is rudimentary, and entirely formed of cartilage. One of the ver- 
 tebral bodies in the dorsal region seems also to be entirely formed 
 of cartilage. The vertebral column is surmounted by several masses 
 of bone and cartilage, which probably represent the base of the 
 skull and facial bones. The axis is doubled almost at right angles 
 in the dorsal and lumbar regions. A small opening, in which a 
 bristle is inserted, is seen in the mesial line at the most anterior 
 part of the foetus ; it is apparently a vessel, probably a median 
 carotid. 
 
 In front of the hair, at the anterior part of the foetus, is a frontal 
 proboscis, considerably enlarged and perforated at its free extre- 
 mity : it is extremely similar to the same structure in cases of 
 cranial arrest. (See Nos. 162 et seq.) 
 
 The body-cavity is not divided by any diaphragm, and is almost 
 filled by a saccular dilatation of the intestine, which forms a blind 
 sac in front of the sacrum ; there is no anus. A blind coil of intes- 
 tine fills the cavity of the umbilical cord and communicates with 
 the main intestinal cavity at the umbilicus. The whole was filled, 
 according to Mr. Young, with a dark fluid resembling meeonium, 
 although there is apparently no vestige of a liver. In the upper 
 part of the trunk the lungs may be distinctly seen, compressed 
 against the vertebral column. No other internal organs have been 
 developed. The external generative organs are probably those of 
 un imperfect male. The penis is rudimentary, perforated at its 
 
 D 2 
 
30 ABNORMAL CONDITIONS OF THE AXIS. 
 
 extremity only, and having a blind urethral pouch immediately 
 beneath its root. There is no bladder. 
 
 Presented by G. W. Young, Esq. 
 
 136. A cyst with a portion of the stomach and jejunum from a 
 
 lad between 15 and 16 years of age. The cyst contained 
 the imperfect male foetus preserved in the next prepara- 
 tion, No. 136. The case was described in a pamphlet by 
 N. Highmore, Esq., in 1814. 
 
 The cyst in this case is intimately and extensively connected 
 with the duodenum and jejunum. A portion of the stomach, which 
 is excessively elongated, is seen on the left of the preparation ; it 
 has been filled with horsehair. The duodenum is seen opening 
 on the left into the upper part of the cyst ; from this point the 
 intestine forms part of the wall of the cyst as far as the right 
 extremity of the preparation, where the opening of the jejunum 
 is seen ; a piece of glass tube has been inserted into this opening. 
 The intestine was below and not above the cyst when it was in 
 situ. The interior of the wall of the cyst, except that portion of 
 it which was formed by the intestine, is covered with ragged pro- 
 cesses of membrane, so that it has a villous appearance. The funis 
 arose from the posterior and upper part of the cyst (the lower part 
 in the preparation). The whole was very vascular, and the lad 
 died of haemorrhage into its interior. 
 
 Presented by N. Highmore, Esq. 
 
 137. The foetus from the same. There is no head, but some slips- 
 
 of membrane unite the upper part of the vertebral column 
 with the funis ; they represent the membranes of the brain. 
 A quantity of long, thick, matted hair is seen growing 
 from near the same point, probably from what should 
 have been the frontal region. The limbs are very ill pro- 
 portioned and are violently flexed. The hands are at 
 right angles to the arms. The whole of the left leg has 
 apparently been absorbed, a large denuded surface on the 
 side of the pelvis being the only indication of its ever 
 having existed. The right foot is bent inward as in ta- 
 lipes varus. The sharp angles of the joints have under- 
 gone absorption, the bones being denuded and partially 
 removed at these points. The upper part of the body has 
 a long fleshy papilla growing from it, enlarged and hol- 
 low at its extremity ; it is undoubtedly a frontal pro- 
 boscis. In Mr. Highmore's original description it has 
 
DUPLICITY. 37 
 
 been mistaken for a nipple, and hence the foetus was er- 
 roneously described as a female. The generative organs 
 are those of an imperfect male, consisting of a rudimentary 
 penis invested by a very voluminous circular prepuce. 
 
 The fun is is short and thick, and when recent the foetus 
 was covered with sebaceous secretion. 
 
 Presented by N. Higkmore, Esq. 
 
 C. By Adhesion. 
 
 This is a much less intimate mode of union, and probably takes 
 place at a much later stage of development. It occasionally 
 happens that both foetuses are well developed, especially when they 
 adhere by the skulls, the brains and their membranes remaining 
 separate ; much more frequently one foetus is very defective ; it 
 often forms a mere tumour, especially when adherent to the 
 nates of the other. 
 
 a. Craniopagus. 
 
 138. The skull of a Bengalee child, with a second imperfect skull 
 attached to the anterior fontanelle, which is widely ex- 
 tended. The base of the second skull is much contracted, 
 the foramen magnum being almost closed. All the bones 
 of the face are much smaller than those of the supporting 
 skull. The faces are turned in almost opposite directions, 
 so that the left frontal bones of one skull articulate by 
 suture with the right parietals of the other, and vice versa. 
 
 The history of this skull and an account of the child are given 
 in the Phil. Trans, vol. Ixxx. p. 296, from which the following 
 particulars are extracted : 
 
 The child was a male, it was more than four years old at the 
 time of its death, which was caused by the bite of a cobra. It was 
 very emaciated, a fact attributed to the parents having used it as 
 a show, always keeping it covered up, except when payment was 
 made for its exhibition. The woman who acted as midwife was 
 terrified at the appearance of the additional head, and tried to de- 
 stroy the child by throwing it on the fire : it was rescued after 
 one eye and ear were considerably burnt. 
 
 There was no trunk to the second head ; but it was surmounted 
 by a short neck terminating in a rounded tumour, which is stated 
 by one observer to have been quite soft at the age of two, and 
 by another to have been quite hard and cartilaginous at the age of 
 four. Its external ears were represented by mere folds of skin, and 
 
38 ABNORMAL CONDITIONS OF THE AXIS. 
 
 there was no auditory meatus. The normal face and head were not 
 malformed. The brains were distinct, each invested in its own 
 membranes ; the dura mater of each adhered to that of the other 
 at the point of contact. The chief supply of blood to the upper head 
 was by a number of vessels passing from the membranes of one 
 brain to that of the other. The movements of the features of the 
 upper head appear to have been purely reflex, and by no means to 
 have been controlled by the feelings or desires of the child. The 
 movements of the eyes of the accessory head did not correspond 
 with those of the child, and the eyelids were usually open, even 
 during sleep. 
 
 Hunterian. 
 
 b. Ischiopagus. 
 
 A second foetus, or more generally an amorphous tumour of 
 connective tissue containing bones, cartilage, and other remains 
 of a second foetus, adheres to the gluteal region. 
 
 139. A tumour of somewhat conical form, composed of fibrous 
 tissue, fat, and cartilage, which was removed from the 
 nates of a child about 14 months old. A papilla at its 
 extremity appears to represent very obscure indications 
 of a limb. The remains of a portion of intestine, origi- 
 nally blind at each extremity, and about 3 inches long, 
 is seen at its base. It originally contained a fluid re- 
 sembling meconium. The child recovered quickly from 
 the operation. The tumour has been cut through verti- 
 cally to show its structure. 
 
 Presented by T. Blizard, Esq. 
 
 Class III. EXCESS OF GROWTH (GIANTS). 
 [Arranged in the Osteological Series.] 
 
 Class IV. ARREST OF GROWTH (DWARFS). 
 [Arranged in the Osteological Series.] 
 
 Class V.- ARREST OF DEVELOPMENT. 
 
 Subclass I. Cranial arrest. 
 
 Two principal forms of arrest of development occur in the 
 cranial region. Either the lateral arches fail in their develop- 
 
ARREST OF DEVELOPMENT. 39 
 
 ment, giving rise to median fissures, or the cranio-facial axis fails 
 and undergoes atrophy or absorption, and the lateral arches unite 
 prematurely, so that fusion of the lateral organs results. In 
 the first case there is usually some shortening of the cranio- 
 facial axis, at least in extreme cases. In the second form the 
 axis becomes narrowed, or is absent in parts of the skull, and the 
 corresponding nervous and facial structures fail to be developed. 
 The presence of lateral parts corresponding to the several por- 
 tions of the axial region affords a strong indication that the axial 
 parts are not absent from the commencement of development, 
 but that they fail to be developed and become atrophied at an 
 early stage. The most common form originates in the absence 
 or failure of the parts developed from the investing mass in front 
 of the notochord, the olfactory lobes and nasal capsules are then 
 deficient. When the investing mass fails more posteriorly the 
 eyes and mesencephalon are found wanting. When the invest- 
 ing mass fails in front of the ear-capsules, so that the basi- 
 occipital ends in a point between them, the mandible is absent ; 
 and in extreme cases, when the structures normally developed 
 in the investing mass in front of the ear-capsules all fail, the 
 tympanic cavities are fused in front. It frequently happens that 
 the mesencephalic or epencephalic region are deficient, whilst 
 the anterior and posterior portions of the cranio-facial axis are 
 developed. The changes which produce these abnormal condi- 
 tions probably commence in the investing mass, and not in the 
 subsequently formed bones, since failure as frequently occurs 
 between the bask>ccipital and basisphenoid as in either of these 
 bones. In this case the anterior part of the basioccipital and 
 the posterior part of the basisphenoid are equally arrested. The 
 nerve-centres appear to be always arrested at points correspond- 
 ing to the deficient portions of the axis, so that it appears im- 
 probable that the malformation originates in deficiency of the 
 facial arches. Rarely one lateral half only of a portion of the 
 cranium is arrested, the other being normally developed. 
 
 IN FISHES. 
 
 140. The anterior portion of an eel with complete deficiency of 
 the face in front of the eyes. The mandible extends be- 
 
40 ABNORMAL CONDITIONS OF THE AXIS. 
 
 yond the anterior extremity of the truncated skull. The 
 cranium and part of the spinal canal has been laid open. 
 The four anterior ganglia are much compressed from 
 before backwards. The anterior pair (olfactory) have 
 displaced the second pair, the cerebral hemispheres, and 
 lie partially between instead of entirely in front of them. 
 
 141. The head of a young Salmon with a similar truncated face; 
 
 the maxillse are placed almost at right angles to their 
 
 normal position, and lap over the mandible on either side. 
 
 Presented by Mr. Shepherd, 1871. 
 
 142. A vertical longitudinal section of the anterior part of a Carp, 
 
 with complete deficiency of the face in front of the eyes. 
 The development of the mandible is likewise defective ; 
 it does not extend beyond the truncated face. 
 
 Hunterian. 
 
 IN BIRDS. 
 
 143. A Sparrow with a' deep cleft dividing the mandible and 
 
 lower beak in the mesial line. Hunterian. 
 
 144. A fcetal Chick in which the anterior portion of the cranio- 
 
 facial axis is absent. The eyes are fused into a single 
 organ. The upper beak and the maxillary and frontal 
 arches are entirely wanting. Purchased. 
 
 IN MAMMALS. 
 
 A. Facial arrest. 
 
 Facial arrest in its slightest degree consists in arrested deve- 
 lopment of the intermaxillaries and maxillary bones, so that a 
 cleft is left between them, constituting cleft palate or Hare-lip. 
 The nasal septum is defective in the more severe forms, or the 
 whole anterior part of the axis, including the ethmoid bone, may 
 be deficient. All the facial bones may be very defective, with 
 shortening of the bones of the base of the skull. Very frequently 
 this shortening appears to be accompanied by an increase of 
 breadth in the axial bones, giving rise to considerable clefts be- 
 tween the arrested parts of the face. 
 
 145. A portion of the skull of a six-months* foetus with consi- 
 
 derable deficiency of the maxillae and palate-bones, giving 
 rise to a wide cleft in the palate. The vomer supports 
 
ARREST OF DEVELOPMENT. 41 
 
 the intermaxillaries, which are separated by a fissure on 
 either side from the maxillae. 
 
 Presented by Sir W. Fergusson, Bart., 1865. 
 
 146. A portion of the skull of a new-born child, with considerable 
 
 divergence of the pterygoid process and palate-bones. 
 There is entire deficiency of the bony palate, and the 
 maxillae are widely separated from each other and from 
 the premaxillaries. Presented by Sir W. Fergusson, Bart. 
 
 147. A portion of an adult skull in which there is a cleft nearly 
 
 an inch wide between the lateral halves of the bony 
 palate. The vomer is bent over to the left side, and is 
 united to the left half of the palate. The alveoli are very 
 defective. There are only two teeth on the left side. 
 
 Presented by Sir W. Fergusson, Bart. 
 
 148. The intermaxillary bones from eight cases of cleft palate 
 
 in infants. Presented by Sir W. Fergusson, Bart. 
 
 149. The intermaxillary bones from two cases of cleft palate in 
 
 children. Presented by Sir W. Fergusson, Bart. 
 
 150. The intermaxillary bones from a case of cleft palate in an 
 
 adult. Presented by Sir W. Fergusson, Bart. 
 
 151. A dissection of the tensor and levator palati muscles and 
 
 the neighbouring parts in a case of cleft palate in the 
 
 adult. 
 
 The soft palate only -is apparently cleft in this case, but the 
 bones are implicated slightly, although to a much less extent than 
 in the foregoing preparations. The preparation is of special in- 
 terest because it shows the manner in which the levator palati and 
 palato-pharyngei muscles keep the edges of the soft palate apart. 
 The upper fibres of the superior constrictor, which act as their 
 antagonist, are unusually well developed. This is the original 
 dissection on which Sir W. Fergusson founded his operation of 
 Staphylorophy, which consists in dividing the fibres of the levator 
 palati, palato-pharyngei, and palato-glossi. The preparation is 
 minutely described in his original description of the operation, 
 published in 1845, 'Trans. Med.-Chir. Soc.' vol. xviii. p. 273-301. 
 Presented by Sir W. Fergusson, Bart. 
 
 152. The head of a young Lion born in the Zoological Gardens, 
 
 March 1862, with cleft palate and arrested growth of the 
 septum narium. The litter consisted of two, this and 
 another in the same condition. The alveoli of both jaws 
 
42 ABNORMAL CONDITIONS OF THE AXIS. 
 
 are arrested also. Several other Lion-cubs born in the 
 Gardens have been similarly affected. Purchased. 
 
 153. The skull of a new-born Calf with a cleft between the max- 
 
 illary bones, and defect of the palate-bones and pterygoid 
 processes. The whole skull is shorter and broader than 
 the normal type. There is considerable shortening and 
 deformity of the mandible. Hunterian. 
 
 154. The skull of a similar Calf with more considerable shorten- 
 
 ing of the whole axis, and extreme curvature of the rami 
 of the mandible. Presented by T. Wormald, Esq. 
 
 155. A portion of the head of a Human infant, with arrested 
 
 development of the ethmoid bone, absence of foramina 
 in the cribriform plate, of the nasal septum and premax- 
 illaries. There is a single median nostril and a deep 
 cleft between the lateral halves of the upper lip. In this 
 case the foramen ovale of the heart was patent, the testes 
 had not descended, and there were six digits on each 
 hand and one foot. (See Nos. 308-310.) 
 
 Presented by R. Partridge, Esq. 
 
 156. The head of a female Human foetus, with a broad cleft in 
 
 the upper lip continuous with the nostrils, arrest of the 
 septum narium, and entire deficiency of the bony palate. 
 There is also apparently considerable deficiency of the 
 skull in the occipital region, similar to that exhibited in 
 No. 279. Hunterian. 
 
 157. The head of a Human foetus with arrest of the ethmoid bone 
 
 and nasal septum. The eyes are approximated. There 
 is no palate. The nostrils are absent, and the upper lip 
 is deeply cleft in the mesial line. A section has been 
 made through the mandible and tongue to exhibit the 
 condition of the roof of the mouth and the nasal cavity. 
 
 Presented by Sir W. Blizard. 
 
 158. A portion of the head of a Human foetus with shortening 
 
 of the whole cranip-facial axis. The right eye is abnor- 
 mally small, and the left is deficient: its eyelids are 
 wanting, and a mere depression marks the position of the 
 orbit. The palate and the upper lip are entirely wanting. 
 The maxillary and naso-frontal processes remain distinct. 
 The external ears present numerous abnormal lobules. 
 The base of the skull has been dissected to show the 
 
ARREST OF DEVELOPMENT. 43 
 
 imperfect condition of the middle ear and tympanic 
 bones. The right Eustachian tube is marked by a black 
 bristle ; it is a mere groove open below. 
 
 159. A vertical section of the head of a Human foetus in which 
 the palate is entirely deficient. A groove above the 
 mouth, marked by a bristle, represents the nasal cavity. 
 The cribriform plate of the ethmoid is very small, its 
 vertical plate is absent. The palato-pterygoid and max- 
 illary process (suborbital arch) are absent. The eye is 
 abnormally small. The external ear is represented by a 
 small lobule; there is no meatus. The cavity of the skull 
 occupied by the middle cerebral lobe is much enlarged ; 
 the remainder of the cranial cavity is correspondingly 
 
 contracted. 
 
 
 
 13. Prosencephalic arrest. 
 
 Syn. Cyclops, Gurlt. 
 
 Ehinocephalus, Cyclocephalus, Ethmocephalus, Geoff. 
 
 W. Vrolik* first ascribed the origin of the following forms to 
 arrest of development of the anterior portion of the investing 
 cartilage of the notochord ; and there can be little doubt that 
 this is the most satisfactory explanation yet arrived at. The 
 trabecular arch and the structures arising from it are always 
 absent or defective. The nasal septum is either entirely absent, 
 or is represented by a defective vomer. The whole ethmoid bone 
 is usually wanting. There are traces of inferior spongy bones 
 in the frontal proboscis, a process arising from {fie union of the 
 naso-frontal processes. There is sometimes a single nostril, 
 sometimes a pair beneath the eyes, between the united sub- 
 ocular arches, when a defective nasal cavity exists between the 
 maxillae. More frequently the proboscis is perforated by a 
 nostril, and contains a cavity extending back to the skull, in 
 which a pair of cartilaginous spongy bones are situated. In 
 such cases the maxillary bones are very massive and are fused in 
 the median line. The orbits are united into a single cavity, and 
 the eyes are more or less perfectly fused, sometimes forming a 
 single globe. The brain exhibits unmistakable signs of arrest. 
 
 * Over den Aard en Oorsprong der Cyclopie : Amsterd. 1834. 
 Miillor's Arch. 1836. 
 
^4) ABNORMAL CONDITIONS OF THE AXIS. 
 
 The corpus callosum is almost always absent, the fornix is ab- 
 sent or rudimentary, the cerebral lobes are usually very defec- 
 tive and are fused in front with each other ; the third and lateral 
 ventricles, in most cases, are opened out into a large cyst, which 
 occupies the greater part of the cranial cavity, a condition which 
 may well induce the belief that the cause of the phenomenon is 
 probably internal hydrocephalus at a very early period of em- 
 bryonic life. It is certain that hydrocephalus often accompanies 
 this condition : examples are seen in specimens Nos. 185 and 186. 
 
 a. Hhinocephalus. 
 
 Syn. Rhmocephalus and Cyclocephalus, Geoff. 
 Cyclops, Gurlt. 
 
 In Rhmocephalus the naso-frontal processes form a frontal 
 proboscis. 
 
 160. A foetal LamVs head with entire deficiency of the axis in 
 
 the facial region, a solid frontal proboscis, partially fused 
 eyes, and a pair of imperfect nostrils between the maxillae. 
 The roof of the skull has been removed to show the com- 
 plete absence of the ethmoid bone and fusion of the optic 
 foramina. Hunterian. 
 
 161. The brain of the same showing the fusion of the hemi- 
 
 spheres in front, the absence of the corpus callosum, the 
 open condition of the large third ventricle, and the com- 
 plete absence of the olfactory nerves. Hunterian. 
 
 162. The head of a foetal Boar, with complete deficiency of the 
 
 facial axis. The eyes are partially fused. An orifice cor- 
 responding to the nostrils is situated at the extremity of 
 the proboscis. Hunterian. 
 
 163. A similar preparation with the eyes more closely united. 
 
 Hunterian. 
 
 164. The head of a foetal Sow, similar to the last two, but with 
 
 the eyes still more closely united. Hunterian. 
 
 165. The head of a foetal Sow, in which the frontal proboscis is 
 
 turned back over the forehead. The eyes are fused as 
 far as the edges of the cornese. 
 
 166. The head of a foetal Pig with the eyes fused into a single 
 
 globe. The roof of the skull has been removed to show 
 
ARREST OF DEVELOPMENT. 45 
 
 the brain. The cerebrum is very small ; its anterior lobes 
 are completely fused. The middle lobe of the cerebellum 
 and the corpora quadrigemina are proportionately very 
 large ; the latter are not covered by the cerebrum. 
 
 Hunterian. 
 
 167. The head of a similar foetal Pig. The roof of the skull has 
 
 been removed. The cerebral lobes are completely fused 
 in front. The whole brain scarcely fills a quarter of the 
 cranial cavity. Hunterian. 
 
 168. A similar preparation, but the eye is apparently very de- 
 
 fective. The cornea and lens seem to have been arrested 
 in their growth. The cornea is conical. Hunterian. 
 
 169. A similar specimen with the side of the face dissected to 
 
 show the form of the skull, the superior maxillary bone, 
 and pterygoid processes. The zygoma and the ascending 
 ramus of the mandible have been removed. The pro- 
 longation of the frontal bones into the proboscis is well 
 seen in this preparation. Mus. Brit. 
 
 170. The head of a foetal Pig with cyclopia, dissected, to show 
 
 the condition of the brain and nerves. The distribution 
 of the ophthalmic branch of the fifth to the proboscis, and 
 the superior maxillary nerves to the maxillae, is well seen 
 on the right side of the head. The brain is exposed on 
 the left side. The small hemispheres are fused together. 
 The"' corpora quadrigemina and the cerebellum are not 
 covered by the cerebrum. 
 
 171. A dissection of the head of an Indian wild Boar with simi- 
 
 lar deficiencies. 
 
 The upper preparation consists of a section of the head. The 
 cavity of the proboscis extends back to the cranial bones and con- 
 tains a cartilaginous fold, probably the inferior spongy bones. The 
 lower preparation shows TiHe maxilla and teeth, the pterygoid and 
 styloid process, the middle ear and its ossicles, together with the 
 gustatory and hypoglossal nerves. 
 
 172. A foetal Boar with similar deficiencies. There is consi- 
 
 derable inequality of development on the two sides, with 
 consequent dislocation of the eye. Hunterian. 
 
 173. A foetal Hare with similar deficiency. The frontal pro- 
 
 boscis is comparatively small. 
 
 Presented by A. Newton, Esq. 
 
46 ABNORMAL CONDITIONS OF THE AXIS. 
 
 174. A foetal Kitten with partial fusion of the eyes and a small 
 
 frontal proboscis. Hunterian. 
 
 175. A male Human foetus, about the seventh month of gesta- 
 
 tion, with deficiency of the facial axis and a frontal pro- 
 boscis. The eyes are contained in a single median orbit 
 and fused as far as the corneas. The right external ear 
 and the thumb of the same side are very defective. 
 
 Mus. Brit. 
 
 ] 76. The head of a Human foetus similarly affected. A trans- 
 verse vertical section has been made through the poste- 
 r i r P^ r t of the head to show the condition of the brain. 
 The section passes through the corpora quadrigemina, 
 the fourth ventricle, and the cerebellum. The corpus 
 callosum is absent, the fornix is rudimentary. The cor- 
 pora quadrigemina are very large, the cerebrum is small, 
 and entirely contained in the anterior portion of the skull. 
 The third ventricle, together with the lateral ventricles, 
 forms an enormously dilated cyst, occupying the whole 
 of* the back and upper part of the cranial cavity. 
 
 Presented by C. H. Welch, Esq., 1868. 
 
 177. The posterior part of the brain of the same foetus. 
 
 Presented by C. H. Welch, Esq., 1868. 
 
 178. A longitudinal vertical section of the head of a similar 
 
 foetus. The cerebral lobes are very small, and exhibit an 
 unmistakable condition of arrest. The corpus callosum 
 is absent, and the fornix is rudimentary. The condition 
 of the ventricles as well as the rest of the brain is similar 
 to that seen in the last preparation. The cavity of the 
 proboscis extends back to the dura mater. 
 
 b. Arhynchus. 
 
 Syn. Cyclops Arhynchus, Gurlt. 
 
 In the following preparations the frontal proboscis is absent, 
 indicating a still higher degree of anterior facial arrest. 
 
 179. The head of a foetal Lamb with the eyes partially fused 
 together. The upper part of the skull has been removed 
 to show the small size of the basisphenoid, the persistence 
 of the trabeculae cranii, and the absence of the presphe- 
 noid and ethmoid bones. The optic foramina are fused 
 
 /e-<t*m t&V 
 H 
 
ARREST OF DEVELOPMENT. 47 
 
 into a single foramen. The mandible projects consider- 
 ably in front of the united maxillae. 
 
 Presented by W. R. Gilbert, Esq. 
 
 180. The brain of the same. The anterior cerebral lobes are 
 
 completely fused together. Behind the cerebrum is a 
 large triangular space, corresponding to the third and 
 lateral ventricles ; the fornix is seen crossing this space. 
 The corpus callosum is completely absent. 
 
 Presented by W. R. Gilbert, Esq. 
 
 181. The skull of a similar foetal Lamb. The mandible projects 
 
 more than in No. 179. 
 
 182. The skull of a foetal Horse, with a large median orbit. The 
 
 axis is entirely wanting in front of the basioccipital. 
 There are traces of a vomer between the solid pterygoid, 
 palatine, and maxillary bones, but there is no trace of a 
 nasal cavity. The mandible projects an inch and a half 
 beyond the maxilla. The cranial cavity is much con- 
 tracted, and probably only contained a cerebellum. 
 
 183. A fetal Kitten with complete fusion of the eyes. 
 
 Hunterian. 
 
 184. A similar Kitten, with the thoracic and abdominal cavities 
 
 laid open, to show the perfect condition of the internal 
 organs. Hunterian. 
 
 185. The head of an hydrocephalic foetal Pig, with deficiency of 
 
 the facial axis and fusion of the eyes into a single globe. 
 The vertex is occupied by a very large cyst. Hunterian. 
 
 186. A Human foetus with similar deficiency of the cranio-facial 
 
 axis and complete fusion of the eyes. The cerebro- spinal 
 canal has been laid open. The whole cavity has evidently 
 been occupied by a large water-cyst. The head is doubled 
 back on the contorted spinal column, so that its axis is 
 almost parallel with that of the vertebral column. There 
 is complete deficiency of the occipital region and extreme 
 spinal bifida. The preparation should be compared with 
 Nos. 278, 279. 
 
 c. Anopia. 
 
 In the following preparations the. deficiency extends still fur- 
 ther back ; the trabecular arch is entirely wanting ; and the eyes 
 are rudimentary or absent, although the orbit remains. 
 
48 ABNORMAL CONDITIONS OF THE AXIS. 
 
 187. The head of a foetal Pig with entire deficiency of the facial 
 
 axis, naso-frontal processes, and eyes. There is a V-shaped 
 fissure in the position of the eyelids, which has been en- 
 larged on the right side to show the complete deficiency 
 of the eye. The skull has been opened above, and the 
 cerebellum is seen to be the only portion of the brain it 
 contains. Mus. Brit. 
 
 188. A portion of the occipital and parietal bones of the same. 
 
 Mus. Brit. 
 
 189. The head of a foetal Pig with anterior deficiency of the 
 
 facial axis and absence of the eyes. The maxillary pro- 
 cesses are separated by a deep wide fissure, so that the 
 two halves of the snout are turned outwards and upwards. 
 
 Hunterian. 
 
 C. Mesencephalic arrest. 
 Syn. Anopia. 
 
 It sometimes happens that the middle of the cranial axis and 
 cavity are deficient, whilst the anterior cerebral lobes and the 
 anterior facial region are normal. In this condition the eyes 
 are rudimentary or absent. The tentorium divides the cranial 
 cavity, sometimes to such an extent as entirely to separate the 
 cerebral hemispheres from the cerebellum. 
 
 190. A vertical longitudinal section of the head of a Lamb, in 
 
 which the cerebellum is cut off from the cerebrum by the 
 tentorium. The axial parts between the cerebrum and 
 cerebellum are entirely wanting. The eye is very small 
 and rudimentary. There is atresia of the oesophagus, the 
 upper part of which is apparently entirely wanting. The 
 pharynx is wanting and the mouth ends in a pouch behind 
 the tongue. 
 
 191. Half the skull of the same. The bones are all present but 
 
 the orbito-sphenoids, which are represented by membrane 
 only. The frontals are much elevated in front and de- 
 fective behind; the parietals and all the bones behind 
 the frontals are very small. The eye on this side was 
 exactly like that on the other. 
 
 D. Epencephalic arrest. 
 
 The axis of the skull immediately in front of or between the 
 
AHREST OF DEVELOPMENT. 49 
 
 ear-capsules is sometimes arrested. In the less marked forms 
 (agnathid) only the mandibular arch fails, but the posterior por- 
 tion of the cranial cavity is contracted. In the more marked 
 forms (synotia} the tympanic cavities coalesce, the hyoid arch is 
 constantly present, and the mandibular is always wanting. 
 
 a. Agnathia. 
 
 The brain-case is slightly contracted behind, especially im- 
 mediately in front of the ear- capsules, the mandible is absent. 
 The eyes and ears are approximated below, but the mouth and 
 pharyngeal cavities are continuous. 
 
 192. The head of a foetal Pig with total deficiency of the mandi- 
 
 ble. The eyes and ears are slightly approximated below. 
 Presented by R. Semple, Esq., 1820. 
 
 193. A similar specimen. The roof of the skull has been re- 
 
 moved to show the reduced size of the brain-case and 
 cranial axis behind. 
 
 b. Synotia. 
 Syn. Monstres Otoc^phaliens, Geoff. 
 
 The tympanic cavities are united below, the tympanic and squa- 
 mosal bones being fused together, although the periotic capsules 
 retain their normal position. This condition is explained by the 
 view that the tympanic and squamosal bones are integumental 
 ossifications, as has been pointed out by Mr. W. K. Parker. 
 Their position is most variable in malformations, whilst the 
 primitive ear always retains its normal relations with the axis. 
 The external ears are more or less fused together a little 
 above the hyoid bone ; there is usually only a single meatus 
 externus, and this communicates with the pharynx by an open 
 spiracle. The mouth is always completely separated from the 
 pharynx by the downward growth of the suborbital (maxil- 
 lary) arches. The lungs are commonly well formed, and are 
 inflated at birth by the passage of air through the spiracle or 
 spiracles, for there are two when the external meatus is double. 
 Sometimes the cranial and facial axes remain in their normal 
 relation with each other in animals, the cribriform plate of the 
 ethmoid remaining nearly vertical ; but sometimes the facial is 
 
 E 
 
50 ABNORMAL CONDITIONS OF THE AXIS. 
 
 bent at right angles to the cranial axis, and the cribriform plate 
 forms part of the floor of the brain-case, the whole brain being 
 pressed forward by the contraction of the posterior portion of the 
 skull. 
 
 In cases of this character the ethmoid bone and nasal capsule 
 are also often deficient. These form a connecting link between 
 epencephalic and prostho-epencephalic arrest. \ 
 
 194. A longitudinal vertical section of the head of a foetal Lamb, 
 
 with deficiency of the lower jaw and mouth. The bullse 
 of the ears and malar bones are fused beneath. The facial 
 and cranial axis are in the same line. The median struc- 
 tures of the brain are all more or less defective behind, 
 and the lateral halves are fused in the median line. The 
 cerebral hemispheres, corpus callosum, and fornix are 
 normal. The eyes were approximated and directed down- 
 wards. The pharynx has not been preserved, but was 
 probably similar to that in the following preparations. 
 
 Presented by Sir E. Home, Bart. 
 
 195. The skeleton of the other half of the same head. The fusion 
 
 of the squamosal bones, zygoma, malar, and superior max- 
 illary bones across the mesial line below is well seen. The 
 basisphenoid and presphenoid bones are absent, and the 
 basioccipital is narrowed in front. 
 
 Presented by Sir E. Home, Bart. 
 
 196. The head and neck of a foetal Lamb, with deficiency of the 
 
 mandible and fusion of the ears. The facial is at right 
 angles to the cranial axis, so that the ethmoid forms part 
 of the floor of the skull-case. 
 
 The side of the skull has been partially removed to show the 
 base from within. A section has been made through the nasal 
 cavity, and the pharynx has been laid open. A purple glass rod 
 marks each of the following : The optic foramina, foramina ro- 
 tunda, and the tongue, a hollow organ situated above the anterior 
 part of the pharynx. The only external opening of the pharynx 
 is hy the Eustachian tubes and external auditory meatuses. The 
 memhrana tympani were absent. Blue glass rods mark the sphe- 
 noidal fissure, the foramen ovale, the external auditory meatus, 
 and the anterior condyloid foramen. A white rod has been placed 
 in the jugular foramen. 
 
 Hunterian. 
 
ARREST OF DEVELOPMENT. 51 
 
 197. The anterior portion of the brain of the same, showing the 
 
 entire absence of the corpus callosum and fornix. The 
 remainder of the brain had decomposed before it was re- 
 moved from the cranial cavity. Hunterian. 
 
 198. The head of a fcetal Lamb with the eyes fused into a single 
 
 median globe, the whole ethmoid region being absent. 
 The maxillae are large, and are placed at right angles to 
 the cranial axis. All the internal parts have been re- 
 moved, so that no accurate description can be given. 
 
 Hunterian. 
 
 199. A vertical longitudinal section of the head and neck of a 
 
 foetal Lamb, with deficiency of the facial axis and pre- 
 
 sphenoid, and complete fusion of the eyes. The brain is 
 
 very defective in front. 
 
 The maxillae are at right angles to the cranial axis ; they form 
 large cancellous masses of bone, which are fused together in the 
 mesial line. There is no vestige of a mandible. The ears are 
 fused together, so that there is a single auditory meatus commu- 
 nicating with the pharynx by a spiracle. The other characters 
 are precisely similar to those seen in synotia generally. 
 
 Presented by Dr. E. L. Ormerod, 1864. 
 
 E. Prostho-epencephalic deficiency. 
 Syn. Stomocephalie, Geoff. 
 
 The defect of the cranio-facial axis commences between the 
 ear-capsules and becomes gradually more marked in front of 
 this region ; the basisphenoid may be partially developed, but 
 the axis is entirely absent anteriorly to it. No arches are de- 
 veloped in front of the hyoid arch. The tympanic cavities and 
 external ears are more or less fused together. The cranial cavity 
 is small and rounded. The face, when present, consists of a 
 frontal proboscis and a pair of more or less united eyes. Some- 
 times the maxillae are represented by a small papilla. These 
 parts are placed immediately beneath the skull. The term cy- 
 clocephalus has been applied to this form. 
 
 In a more highly arrested condition the face presents only a 
 pair of external ears, sometimes fused together in the median 
 line. An atrophied median eye sometimes exists, but is more 
 commonly absent. In such cases the frontal and maxillary pro- 
 
 E2 
 
52 ABNORMAL CONDITIONS OF THE AXIS. 
 
 bosces are either very rudimentary or wanting. When the ears 
 only are present, the squamosal bones form a shield in front of the 
 skull-case. The term nanocephdlus has been applied to this form. 
 
 The periotic bones always retain their normal position with 
 regard to the axis, and the tympanic bones are usually removed 
 from them. The pharynx always ends blindly above, but often 
 communicates with the exterior by tympanic spiracles. 
 
 The brain is either arrested in its development or, in nano- 
 cephalus, is completely absent, the skull-cavity being occupied 
 by a cyst surrounded by the anterior termination of the medulla. 
 In cyclocephalus in the human subject the axis of the skull re- 
 mains in the same line as that of the vertebral column. 
 
 The most extreme form of cranial arrest produces entire ab- 
 sence of the skull, or a cyst between the external ears terminates 
 the axial canal in front. The term acephalus has been used to 
 designate this malformation. 
 
 a. Cyclocephalus. 
 
 200. The head of a male foetal Pig with a frontal proboscis and 
 
 a pair of eyes fused as far as the cornea. The maxillae are 
 represented by a papilla beneath the eyes. The mandible 
 is absent. The tympanic cavities are united. The ex- 
 ternal auditory meatuses are not fused together : a black 
 bristle is passed through that on the left side into the 
 pharynx. The pharynx has been laid open. The animal 
 was otherwise normal. 
 
 201. A similar preparation in which the eyes are fused into a 
 
 single globe. The ear, pharynx, and larynx are dissected. 
 
 The hyoid arch is perfect. 
 
 On the right side the anterior wall of the external meatus only 
 has been removed, on the left side the tympanum has also been 
 laid open. There was an external opening beneath the bullae into 
 two distinct passages which lead into the pharynx ; these auditory 
 spiracles are marked by two bristles. The median Eustachian tube 
 is also marked by a bristle. The tympanic membranes were both 
 perfect. 
 
 202. The head of a foetal Sow with similar deficiency. In this 
 
 specimen the median eye appears as if it had been much 
 damaged by inflammatory action. 
 
 203. A section through the head of a similar foetal Pig, showing 
 
ARREST OF DEVELOPMENT. 53 
 
 the total absence of the cranio-facial axis in front of the 
 basisphenoid bone. A bristle marks the external opening 
 of the pharynx. Presented by Sir E. Home, Bart. 
 
 204. The tympanic bulla and the labyrinth of the left ear from 
 
 the same. 
 
 205. The head of a Human foetus about the end of the sixth 
 
 month, with a single eye in the mesial line and conjoined 
 
 tympanic bones. There is no vestige of the mandible or 
 
 facial axis. 
 
 A dissection from behind shows the cavity of the skull and 
 pjiarynx. The eye and ears are in front of the axis of the skull, 
 which is perpendicular instead of horizontal. The cranio-facial 
 axis is entirely deficient in front of the basisphenoid. The tongue 
 is well formed, and occupies the upper part of the pharynx. The 
 pharynx opens externally by spiracles communicating with the 
 external auditory meatus. 
 
 206. The posterior portion of the skull and brain of the same. 
 
 The section passes through the cerebellum, pons, corpora 
 quadrigemina, and a portion of the medulla and the 
 fourth ventricle. 
 
 207. The lateral half of the head of a Human female foetus with 
 
 entire deficiency of the facial axis, fusion of the eyes, 
 absence of the mandible, and approximation of the ears. 
 The pharynx opens by the aural passage, through which a 
 black bristle has been passed. A mass of cartilage 
 and several small masses of bone are seen beneath the 
 eye, representing in some degree the deficient facial 
 bones ; there is also slight curvature of the cranial axis 
 forwards. Presented by W. Squire Ward, Esq., 1863. 
 
 208. A longitudinal vertical section of the head and neck of a 
 
 foetal Lamb with complete fusion of the eyes and ears 
 and absence of all the other parts of the face. The ce- 
 rebral lobes are hollow, and all the axial structures of the 
 brain were fused in the median line. The pharynx opens 
 by the median external auditory meatus, which is entirely 
 removed from the auditory capsule. The tympani are 
 absent. A bent purple glass rod marks the passage. 
 
 Hunterian. 
 
 209. The opposite half of the same. Hunterian. 
 
54 ABNORMAL CONDITIONS OF THE AXIS. 
 
 b. Nanocephalus. 
 
 210. The skull of a foetal Lamb with deficiency of the entire axis 
 
 in front of the basisphenoid region. The mandible and 
 all the facial structures,, except a shallow orbit, are absent. 
 The squamosal bones are united beneath the skull. The 
 bullse of the ears are not fused in this preparation. 
 
 Presented by C. B. Rose, Esq., 1869. 
 
 211. A foetal Puppy with a nanocephalous skull. There is a 
 
 very imperfect Cyclops-eye, a soft imperforate frontal 
 proboscis, and a similar structure representing the max- 
 illae. The pharynx opens through the aural tract. The 
 roof of the skull has been removed to show its base from 
 within. The axis terminates in the basisphenoid region, 
 immediately in front of the foramen magnum. All the 
 bones of the skull except those of the ear- capsule are very 
 small ; these are of their normal magnitude, and occupy 
 a very large part of the base of the skull. Mus. Brit. 
 
 212. A nanocephalous foetal Puppy with no eye or orbit j it is 
 
 otherwise similar to the last. Hunterian. 
 
 213. A similar foetal Hare, but without any maxillary proboscis. 
 
 214. A similar nanocephalous foetal Kitten, but without any pro- 
 
 boscis. There is a caeca! foramen representing the orbit. 
 The tympanic bullse are united. The single meatus ex- 
 ternus has been laid open to show the tympana ; beneath 
 these is a passage, marked by a bristle, leading into the 
 pharynx. The thoracic cavity has been opened and the 
 thymus removed to show the normal condition of the 
 heart and lungs. Hunterian. 
 
 215. A microcephalous foetal Pig with fusion of the tympanic 
 
 cavities. A small bifid tubercle on the face is the only 
 remnant of the united and atrophied eyes. There are no 
 other facial organs except a pair of external ears that are 
 united by their bases. The neck and thorax have been 
 laid open to show the perfect condition of the hyoid arch, 
 larynx, trachea, and lungs. The calvarium has been re- 
 moved to show the base of the skull. Hunterian. 
 
 216. The nanocephalous skull of a similar foetal Pig. The squa- 
 
 mosal bones are fused together and form a square pro- 
 jecting plate above the united tympanic bullse. The 
 frontal bones are very defective. The basioccipital is the 
 
ARREST OF DEVELOPMENT. 55 
 
 only bone in the cranial axis, and it ends in a point in 
 front. 
 
 217. The anterior half of a nanocephalous foetal Kitten. The ex- 
 
 ternal ears were united at the base ; but the left lateral 
 half of the head has been removed to show the head in 
 section. A bristle marks the external opening of the 
 alimentary and respiratory tracts. 
 
 218. A microcephalous Human foetus,in which the face is entirely 
 
 wanting, its position being occupied by a pair of ill-formed 
 ears fused together above and below, with a small rounded 
 tubercle between them in the place of a meatus. The 
 skull and spinal canal have been laid open from behied. 
 
 219. -A longitudinal vertical section of the anterior part of a 
 
 nanocephalous foetal Lamb. The brain in front of the 
 medulla is represented by a cyst only. The pharynx 
 opens externally through the united tympanic bullse and 
 external meatus. Presented by Sir W. Blizard. 
 
 220. The atlas and bones of the skull from the other lateral 
 
 half of the same. The anterior part of the skull is seen 
 to be extremely defective. The bones of the ear-capsule 
 retain their normal position, but the tympanic and squa- 
 mous elements were united across the mesial line in front 
 of the defective cranial axis. 
 
 Presented by Sir W. Blizard. 
 
 221. The left half of a longitudinal section of the anterior part 
 
 of a nanocephalous foetal Pig. The cranial bones are very 
 thick. The specimen is in other respects similar to the 
 last. Hunterian. 
 
 222. The right half of the same. Hunterian. 
 
 c. AcepJialus. 
 
 223. A portion of the spinal column and cord of a foetal Lamb. 
 
 The medulla ends in a rounded extremity. It is sur- 
 rounded by a case, partly of membrane and partly of carti- 
 lage, which represents the cranium : a pair of imperfect 
 periotic capsules are imbedded in its walls. Hunterian. 
 
 224. The anterior extremity of a nanocephalous foetal Lamb. The 
 
 head is represented by a pair of ears and an elongated 
 bladder-like cyst, which projects between and above 
 
56 ABNORMAL CONDITIONS OF THE AXIS. 
 
 them. The pharynx is laid open from the side, and a quill 
 is passed into it through each external auditory meatus. 
 Presented by the Prince de Conde. 
 
 225. The anterior portion of a foetal Lamb, in which the head 
 
 is represented by a pair of ears only at the anterior ex- 
 tremity of the axis. The skin has been reflected to show 
 the tympanic bullse, and the auditory meatus has been 
 opened on one side to show the membrana tympani. 
 The pharyngeal cavity has been laid open. 
 
 Presented by Sir W. Blizard. 
 
 226. An injected foetal Pig, in which the axis terminates in the 
 
 same manner. The pharynx is laid open, and bristles are 
 passed on each side from the external meatus of the ear 
 into its cavity. 
 
 A circular fold of mucous membrane divides the cavity of the 
 pharynx into two portions. The upper probably represents that 
 portion which is normally above the soft palate. The ring seems 
 to represent the soft palate ; it has been slit up in front. The right 
 lung and the liver were removed, it is stated, to show more clearly 
 the position of the remaining viscera. The intestine terminates in 
 a blind sac in the umbilical cord. There is no anus, and the 
 kidneys have coalesced in the median line. The lateral toes of the 
 hind feet are abnormally developed. 
 
 227. A male foetal Pig with a pair of ill-developed external ears, 
 
 and a long thin proboscis with an irregular mass of 
 cartilage in its extremity, as the only representatives of 
 the head and face. 
 
 The right side of the back has been dissected to show that the 
 spinal column is truncated above. A minute fistula nearly an inch 
 below the ears communicated with the pharynx, but it has been 
 laid open in front with that cavity. The thoracic and abdominal 
 cavities have been exposed to show the viscera. 
 
 Hunterian. 
 
 Subclass II. Posterior axial arrest. 
 Syn. Monstra Syreniformia, Monopodia, et Symeliens, Geoff. 
 Just as fusion of the lateral organs of the face results from 
 arrest of the facial axis, so arrest of the posterior extremity of 
 the spine gives rise to fusion of the posterior limbs, unless their 
 growth is likewise arrested (see No. 328). In posterior axial 
 arrest the development of the viscera of the lower part of the 
 
ARREST OF DEVELOPMENT. 57 
 
 abdomen is very defective ; the rectum is usually absent, and the 
 colon is greatly enlarged and terminates in a blind extremity. 
 The posterior extremity of the axis is curved back, and has marked 
 indications of arrested growth. The innominate bones are fused 
 below as far as the acetabula, and the femora, when present, are 
 rotated outwards until the knees look backwards; hence the limbs 
 are fused by their external aspect. The lower extremities of the 
 femora may be united into a single symmetrical bone ; the tibiae 
 are usually fused into a single bone, which may either terminate 
 in a blunt stump or support a compound foot, consisting of more 
 or less of the normal pair united by their outer sides, with the 
 heels turned forward. The united limbs are usually curved, so 
 that they are concave in front. The term sympodia has been 
 used to designate this condition ; foetuses so malformed are said 
 to be syreniform. Sometimes one limb is entirely or partially 
 wanting. When it is wanting or inconspicuous, the term mo- 
 nopodia has been used ; the developed limb is usually rotated 
 as in sympodia. 
 
 a. Sympodia. 
 
 228. A Human male foetus at about the seventh month of ges- 
 
 tation, with defective development of the posterior ex- 
 tremity of the axis, with rotation and fusion of the lower 
 limbs. The foot is formed of the inner portion of both 
 feet, and presents four toes, the two inner toes of each 
 foot. The external sexual organs are extremely defective. 
 The abdominal cavity has been laid open to show the di- 
 lated condition of the colon. 
 
 229. A similar foetus in which the fused posterior extremities 
 
 terminate in a two-lobed stump. One lobe is turned 
 back laterally ; it is considerably longer than the other. 
 Presented by J. Stringfield, Esq. 
 
 230. A similar foetus in which the fused limbs ended in a single 
 
 rounded stump. The limb has been dissected to show 
 the arrangement of the muscles. The external vasti form 
 a single muscle behind ; the sartorii are straight, and run 
 down the outer sides of the stump. The two long ad- 
 ductors are close together in front. The tibia terminates 
 in a long blunt cartilaginous point. 
 
58 ABNORMAL CONDITIONS OF THE AXIS. 
 
 231. The viscera of the same. The lungs are very small, and 
 
 both are of nearly equal size ; each has but two lobes. 
 The intestine terminates in an enormously dilated colon. 
 
 232. The external integument of the united limbs of the same 
 
 foetus. 
 
 233. A similar foetus, with the skeleton of the stump and lower 
 
 portion of the body exposed. This specimen shows the 
 peculiar flexure of the spine well, the fusion of the bones 
 of the limb, and their excessive rotation. There are two 
 patellse. Presented by Dr. W. G. Sheppard, 1867. 
 
 b. Monojpodia. 
 
 234. A similar foetus, with the muscles of the lower half removed 
 
 to show the skeleton. The pubes and ischia are fused. 
 There is but one limb, as far as the skeleton is concerned. 
 The tibia terminates in a point. 
 
 Presented by J. F. Steedman, 1864. 
 
 235. The skin of the conical stump-like limb of the same. A 
 
 small nipple-]ike prominence only represents the right 
 limb. Presented by J. F. Steedman, 1864. 
 
 236. The thoracic viscera of the same, exhibiting situs mutatus, 
 
 or transposition. Presented by J. F. Steedman, 1864. 
 
 237. A small Human foetus with monopodia, about the sixth 
 
 month of gestation. A section has been made through 
 the head and trunk as well as through the single stump, 
 which represents the lower limb. The spine is contorted, 
 the pelvis cannot be recognized. The limb terminates in 
 a rounded stump, like that of an amputated limb. The 
 patella is turned backward, and a small square piece of 
 cartilage only represents the distal extremity of the limb. 
 
 Subclass III. Arrest of the whole axis. 
 
 Syn. Amorphus, Gurlt. 
 Omphalosites, Geoff. 
 
 Monstres Paracephaliens et Acephaliens, id. 
 Anideus, id. 
 Acardia, Forst. 
 
 Deficiency of the heart appears to be the most constant cha- 
 racter of general arrest of development. The head is frequently 
 absent ; when present it is always rudimentary and malformed. 
 
ARREST OF DEVELOPMENT. 59 
 
 The tissues are all abnormal \ great hypertrophy of the connec- 
 tive tissue is frequent. The neural canal is seldom normal ; it is 
 more frequently absent or open, or its cavity communicates with 
 large cysts. Parts of the skeleton may be tolerably well formed ; 
 sometimes there are four imperfect limbs, or there may be one 
 or two more or less well-formed limbs only. The alimentary 
 canal is always in a very imperfect condition from obvious arrest. 
 They appear to be always twins to perfect foetuses. Nos. 135 
 and 137, examples of encysted foetuses, exhibit precisely similar 
 conditions. 
 
 238. A Human male foetus without any head or heart. The 
 
 whole body is very oedematous, and has been much dis- 
 torted by the manner in which it was originally suspended. 
 Three extremities are better formed than the remainder of 
 the body; the left anterior, extremity is, however, a mere 
 shapeless mass. The spine has been exposed behind, and 
 its laminae removed on one side to show the cord. It has 
 a single curve with its convexity backwards, and consists 
 almost entirely of cartilage, but is otherwise normal. 
 
 239. The right half of an acephalous acardiac foetus, which has 
 
 been divided longitudinally in the median line. The ver- 
 tebral column is truncated at either extremity, and con- 
 sists of twenty-two segments, with a large spheroidal bony 
 nucleus in each segment, except the first three. 
 The neural canal is closed in by laminae ; it contains a cord, and 
 its upper extremity is filled up and closed by a fibrous mass contain- 
 ing a small cyst. A proboscis ending in an ovate knob terminates 
 the axis in front externally. The thoracic and abdominal cavities are 
 not separated from each other. The upper and back part of the 
 body-cavity is filled with a dense mass of connective tissue closely 
 united to the spine, and probably representing the lungs, with an 
 empty cavity in front bounded anteriorly by a small sternum, pro- 
 bably pericardial. The lower part contains one great median kid- 
 ney, a pair of ureters, and a urinary bladder. The external sexual 
 organs are too imperfect to denote the sex. There are apparently 
 no internal generative organs. There is no liver. The intestine com- 
 mences blindly in a sac in the cord and terminates in a rectum, which 
 is impervious. The integument is much hypcrtrophied. The arm is 
 very imperfect, and is terminated by a single nail. The posterior 
 extremity is furnished with three toes, and is much more normal in 
 form than the arm. The pelvis is apparently fairly developed. 
 
60 ABNORMAL CONDITIONS OF THE AXIS. 
 
 240. The other half of the same. It exhibits similar characters, 
 
 except that there is no arm on this side. 
 
 241 . The right half of a Human amorphous microcephalous foetus 
 
 with great hypertrophy of the connective tissue, so that 
 the whole body has an elongated ovate form. There are 
 no traces of limbs on this side, but a small tubercle 
 represents the lower extremity on the other half (see 
 No. 242). The anterior portion is separated from the 
 rest by a slight constriction ; it is covered with short 
 soft brown hair. There was also a depression dividing 
 that portion which represents the nates, and corresponding 
 to the normal cleft between them. The spinal column 
 has the usual flexures ; but the spines are represented by 
 a long continuous rod of cartilage, probably the remains 
 of the unsegmented investing mass highly developed. 
 Some of the laminae have been removed to show the spinal 
 canal. There are numerous large cysts in the integument 
 behind the spinal column. 
 
 This foetus was one of twins ; the other was well formed. 
 
 The skull presents a very large occipital bone of considerable 
 thickness ; all the other parts of the cranium and face are so de- 
 fective that they cannot be recognized. The tympanic cavities are 
 marked by a blue glass rod ; a black bristle below this marks the 
 opening of the pharynx externally. Masses of cancellous bone 
 above and below the opening probably represent the jaws. The 
 thoracic cavity is filled with reticulated areolar tissue. The ab- 
 dominal cavity is comparatively large. A small stomach is seen 
 at its upper part: this communicates with the pharynx by a 
 narrow pervious oesophagus. There is no pyloric orifice to the 
 stomach, and no duodenum. A quarter of an inch of small intes- 
 tine, blind at either extremity, lies below the stomach, but is in 
 no way connected with it. The large intestine is blind above, 
 makes a sigmoid curve, and terminates in a straight rectum, which 
 opens externally by an anus. There is a considerable cavity in 
 front of the intestine partially occupied by the kidneys (which are 
 fused together into a single gland), the Wolfiian body and its duct, 
 and the urinary bladder. For a further description of these see the 
 account of the other half of the same foetus, No. 242. 
 
 There is a long straight aorta in front of the spine, which ter- 
 minates below in two umbilical arteries, and above by two caro- 
 tids and subclavians. The right umbilical artery is marked by a 
 blue glass rod ; the right carotid is indicated by a bristle. Behind 
 
ARREST OF DEVELOPMENT. 61 
 
 the aorta several sympathetic ganglia are apparent ; and the pneu- 
 mogastric nerve is seen in the neck lying upon the bodies of the 
 vertebrae. 
 
 Presented by John King, Esq., 1868. 
 
 242. The other half of the same foetus, showing the left Wolffian 
 
 body and its relation to the kidneys, which are seen in 
 section. This presents one of the most remarkable in- 
 stances in the permanence and extraordinary growth of 
 a temporary structure yet observed. A slice has been 
 made through the hypertrophied integuments in the 
 region of the inferior extremity, and the imperfect bones 
 of the extremity are exposed. Three small openings, pro- 
 bably those of the mouth, orbit, and meatus auditorius, 
 are indicated by bristles. 
 
 Presented by John King, Esq., 1868. 
 
 243. The right half of the head and neck of an amorphous foetal 
 
 Calf. The skull-cavity is excessively irregular and very 
 small, consisting rather of several bony cysts than of the 
 normal series of bones. The vertebrae of the neck con- 
 stitute an enormous cancellous bony mass, traversed by 
 a very much bent spinal canal and cord. The mouth 
 forms a cavity that does not communicate with the oeso- 
 phagus. There is an ill-shaped external ear. The ex- 
 ternal form is very irregular, from the great hypertrophy 
 of the subcutaneous fat and connective tissue. 
 
 Hunterian. 
 
 244. The other half of the same. . Hunterian. 
 
 245. The skeleton of an amorphous foetal Lamb from Trinidad. 
 
 The foetus consisted of an almost spherical mass about 
 10 inches in diameter, with a pair of fairly developed 
 posterior extremities growing from it. It was covered 
 with thick black wool. It possessed a considerable body- 
 cavity, which contained a coil of intestine, No. 246. 
 The bones form two separate masses. The upper one consists 
 of the ribs and vertebrae ; it was situated in the wall of the sphe- 
 rical mass. The lower one consists of the innominate bones and 
 the inferior extremities. 
 
 The vertebrae are ankylosed by their laminae, and the spines form 
 a single broad blade. The spinal canal is occluded, and there is 
 considerable contortion of the whole column. The ribs are anky- 
 losed together, and are exceedingly broad. 
 
62 ABNORMAL CONDITIONS OF THE AXIS. 
 
 The innominate bones are united in front, but are widely sepa- 
 rated behind ; there is no trace of a sacrum. The femora are arti- 
 culated with the pelvis by imperfect joints. The limbs are fairly 
 developed, but the outer toes have been arrested in their growth. 
 
 Presented by Dr. Huggins, 1866. 
 
 246. The intestine of the same. It is blind at either extremity, 
 
 and forms a large much convoluted mass. 
 
 Presented by Dr. Huggins. 
 
 Subclass IV. Defective closure of the thoracic and abdominal 
 
 cavities. 
 
 This condition sometimes arises from simple arrest of develop- 
 ment ; the abdominal cavity, however, remains open more often 
 as a result of some other malformation, especially curvature of 
 the spine, the union of twins, or displacement of the abdominal 
 viscera. A portion of the diaphragm is occasionally wanting. 
 
 a. Fissure of the sternum (ectopia of the heart). 
 
 Slight fissure of the sternum may exist without displacement 
 of the heart j in the gravest forms there is complete ectopia of 
 that organ. 
 
 247. The sternum of a Goose with deficiency of the median 
 
 ossification. The carina is completely absent, its place 
 being occupied by a fissure. 
 
 248. A foetal Pig with deficiency of the anterior thoracic and 
 
 abdominal walls. The heart and peritoneal sac protrude 
 from the cleft. The anterior membranous investment 
 has been removed. Hunterian. 
 
 b. Ectopia of the abdominal viscera. 
 Syn. Schistocomus, Grurlt. 
 
 Cases of ectopia are most usually accompanied by other mal- 
 formations; hence several are arranged in other parts of the 
 Collection. See Nos. 262, 263, 283, 292. 
 
 249. A female Human foetus at about the seventh month, with 
 
 the greater part of the intestine protruding above the 
 umbilicus. The walls of the sac which contained this 
 intestine have been removed. 
 
 Presented by W. Harris, Esq. 
 
ARREST OF DEVELOPMENT, 63 
 
 250. A female Human foetus, probably at about the seventh 
 
 month, with deficiency of the abdominal parietes. There 
 is a large visceral tumour covered by transparent mem- 
 branous walls. The tumour contains the liver and the 
 greater part of the intestinal canal. There is also arrested 
 development of the forearms. The hands are placed at 
 right angles to the limb. There are but three fingers on 
 the left and four on the right hand. The left leg is 
 shortened. There is curvature of the spine and spina 
 bifida in the lumbar region. Hunterian. 
 
 251. A portion of the trunk of a female Human foetus, with dis- 
 
 placement of the viscera and deficiency of the anterior 
 abdominal wall. The liver and kidneys are dispropor- 
 tionately large. The abdominal parietes immediately 
 above the umbilicus are very thick and loaded with fat, 
 but over the liver they are thin and membranous. 
 
 Presented by Dr. C. H. Bennett, 1868. 
 
 c. Deficiency of the diaphragm. 
 
 252. The trunk of a full-time male foetus with deficiency of the 
 
 left half of the diaphragm. The anterior wall of the 
 thorax and abdomen has been removed. The thoracic 
 viscera have been pushed over to the right side by the 
 intrusion of the abdominal viscera into the thorax. 
 
 253. A male Human foetus with deficiency of the left side of the 
 
 diaphragm and hernia of the intestines into the thorax, 
 with consequent displacement of the thoracic viscera. 
 The thoracic and abdominal cavities are laid open. The 
 abdominal wall was deficient in front. 
 
 Presented by T. Blizard, Esq. 
 
 254. The thorax and viscera of a full-time Human foetus exhibit- 
 
 ing a similar condition. 
 
 255. A male Human foetus at about the fourth month of gesta- 
 
 tion, with deficiency of the diaphragm and anterior ab- 
 dominal wall, and considerable arrest of growth of the 
 left lower extremity. The thoracic viscera are depressed 
 on the left side, and there is lateral curvature of the spine. 
 The case is described in the ' London Medical and Phy- 
 sical Journal/ vol. lii. p. 367. 
 
 Presented by J. C. Yeatman, Esq. 
 
64 ABNORMAL CONDITIONS OF THE AXIS. 
 
 Class VI. MALFORMATIONS OF THE AXIS FROM DISEASE. 
 
 Subclass I. Curvature of the axis. 
 
 The causes producing congenital curvature of the axis are un- 
 known; it may nevertheless be looked upon as the effect of disease, 
 and may occur at any time during foetal life from the earliest 
 period. Except that the resulting malformations are more grave, 
 it differs in no way from ordinary lateral curvature. 
 
 a. Simple curvature. 
 
 256. A Perch with congenital curvature of the spine. 
 
 Hunterian. 
 
 257. A similar specimen, with the integuments and muscles of 
 
 the left side dissected off. Hunterian. 
 
 258. A Trout with congenital curvature of the spine. 
 
 Presented by Sir A. Carlisle. 
 
 259. The embryo of a Goose about the fourth day of incubation, 
 
 with curvature of the axis. Hunterian. 
 
 260. The skeleton of the trunk of a hybrid Duck, bred in St. 
 
 James's Park, with a very remarkable ant ero -posterior 
 flexure of the sacral region, giving rise to considerable 
 shortening of the trunk. 
 
 Presented by H. J. B. Hancock, Esq., 1868. 
 
 261. A foetal Calf removed from one of the lateral halves of a 
 
 divided uterus, No. 450, with considerable curvature of 
 the spine. Hunterian. 
 
 b. With ectopia of the viscera. 
 Syn. Monstres Celosomiens, Geoff. 
 
 262. A Human female full-time foetus with curvature of the spine 
 
 and considerable contortion of the inferior extremities. 
 The anterior thoracic and abdominal wall has been re- 
 moved, with the viscera; it forms the next preparation. 
 The abdominal cavity is so small that all the viscera pro- 
 truded into a large sac situated in front of the abdomen. 
 
 263. The anterior thoracic and abdominal wall of the same, 
 
 showing the opening through which the viscera pro- 
 truded. 
 The anterior wall of the hernial sac has been removed. The 
 
MALFORMATIONS OF THE AXIS FROM DISEASE. 65 
 
 posterior aspect of the abdominal wall has a transverse ridge 
 below the neck of the exomphalos ; this corresponds to the pubic 
 symphysis ; below the ridge the external abdominal wall looks 
 backward and presents a mucous surface of a triangular form. 
 This surface may be looked upon as a kind of cloaca. The intes- 
 tine opens at the apex of the triangle, where it is marked by a 
 green glass rod ; it has probably been cut at this point, as it en- 
 tered the umbilical cord to form an umbilical hernia, a condition com- 
 monly seen in such malformations when the bowel ends in a blind 
 extremity in the cord. The ureters open by two minute openings 
 marked by bristles at the base of the triangle. The vagina is situ- 
 ated in the centre of the space ; it is marked by a purple rod : a 
 papilla, with a blind foramen between it and the vagina, is seen 
 above the latter and between it and the ureters ; its nature is un- 
 certain, but it probably represents the blind rectum ; it is marked 
 by a pale blue glass rod. The liver and intestine are voluminous. 
 The kidneys have coalesced in the median line, and open externally 
 by a single ureter, the other ureter ends in an impervious cord. 
 A purple rod is passed under both ureters. There is a body on 
 the left side which is not paired on the right, it appears to be a 
 suprarenal capsule. The uterus is very large, and its cornua are 
 widely separated. The diaphragm is imperfect, and the heart is 
 much drawn down by the displacement of the abdominal viscera. 
 
 264. The bones of a foetal Calf with strong backward curvature 
 of the spine, and doubling back of the ribs. The pelvic 
 bones are closely approximated, and several of the ribs 
 are fused together. There has evidently been complete 
 ectopia of the viscera. No anterior extremities existed. 
 This condition is nearly identical with, except in the ab- 
 sence of the anterior extremities, that described by Gurlt 
 under the term Schistozomus reflexus. Hunterian. 
 
 Subclass II. Dropsy of the axial canal of the cerebro -spinal 
 
 system. 
 
 Dropsy of the axial canal of the brain and spinal cord is by 
 far the most frequent disease of intra-uterine life. When con- 
 fined to the cord, it gives rise to the condition known as spina 
 bifida ; the neural arches are open behind, although they are 
 usually well developed. In extreme forms a lamina and spinous 
 process is formed on each side of the vertebral column and lies 
 parallel to the transverse process, the canal being completely 
 
66 ABNORMAL CONDITIONS OF THE AXIS. 
 
 opened out by the pressure of the tumour. The tumour consists 
 of the membrana reuniens superior, skin, connective tissue, and 
 the substance of the cord spread out into a cyst, and almost 
 converted into fibrous tissue by hypertrophy of its connective 
 elements. Sometimes the tumour becomes pedunculated by 
 pressure, which the perfect laminae above and below exert upon it 
 during its rapid increase. It is common in the lumbo-sacral 
 region, but extremely rare in the back and neck, except when ac- 
 companied by internal hydrocephalus and considerable malforma- 
 tion of the skull. In the latter case the occipital bone exhibits 
 considerable deficiency. When dropsy occurs at a later period of 
 development, it gives rise to the formation of an enormous cyst 
 on the occiput or vertex, epicephalocele ; and when it occurs to- 
 wards the close of intra-uterine life it produces distention of the 
 skull and great enlargement of its neural arch, hydrocephalus. 
 
 a. Spina bifida. 
 
 265. A portion of the lumbar and sacral region of a new-born 
 
 Child affected with spina bifida. The surface of the 
 tumour is ulcerated. From Sir A. Cooper's Museum. 
 
 266. A vertical section of the lower part of the back and sacrum 
 
 of a new-born Child with spina bifida. In this specimen 
 the chorda equina is incorporated with the walls of the 
 tumour. From Sir A. Cooper's Museum. 
 
 267. A similar specimen with the spinal canal opened from 
 
 behind. Hunterian. 
 
 268. A vertical section of the lumbar and sacral region of a 
 
 Child affected with spina bifida. The lower extremity 
 of the cord is incorporated with the walls of the tumour, 
 from which the lumbar nerves appear to arise. This pre- 
 paration and the last, No. 267, were taken from children 
 born of the same parents. Hunterian. 
 
 269. A sacral spina bifida opened from behind; the sacral nerves 
 
 have been cut through at their junction with the wall of 
 the cyst. 
 
 270. The lumbar vertebrae and sacrum of a new-born Child 
 
 with spina bifida, showing the defective condition of the 
 neural arches. Hunterian. 
 
 271. A dried preparation, consisting of the bones and ligaments 
 
MALFORMATIONS OF THE AXIS FROM DISEASE. 67 
 
 of the lower portions of the vertebral column of a Child 
 with spina bifida. There is a thin membranous cyst cor- 
 responding to the intervertebral ligaments and membrane. 
 The neck of the cyst is very narrow ; but this appearance 
 is much increased by the mode of preparation. 
 
 Presented by Dr. Thurnam, 1871. 
 
 272. A vertical section of a large lumbar spina bifida from a 
 
 Child. The tumour is divided by a vertical septum, 
 which is perforated by a large oval opening. The integu- 
 ment has been removed, but the tumour is covered by 
 subcutaneous fat. 
 
 Presented by R. Partridge, Esq., 1869. 
 
 273. A sacral spina bifida from a Child. The tumour is covered 
 
 with thickened integument ; it has been opened at the 
 side. Its cavity is seen to be divided into loculi by im- 
 perfect septa. 
 
 274. The six lower dorsals, the lumbar and sacral vertebrae of 
 
 a new-born Child with spina bifida. The laminae of the 
 four lower dorsal, lumbar, and sacral vertebrae have been 
 widely separated by dropsy of the cord. The laminae are 
 well formed and are abnormal only in having been opened 
 out by the tumour. This specimen indicates very clearly 
 that spina bifida does not arise from arrest of develop- 
 ment, but from pressure from within.. 
 
 Presented by F. Kiernan, Esq., 1871. 
 
 275. A section of the sacrum of an Adult with spina bifida. 
 
 Presented by Sir W. Blizard. 
 
 276. A portion of the head and neck of a Child which died three 
 
 days after birth from the effects of a ligature applied to 
 a cervical spina bifida. The peduncle of the tumour is 
 marked by a bristle ; it passes between the laminse of the 
 sixth and seventh cervical vertebrae, the spines of these 
 bones being deficient. The laminae of the perfect ver- 
 tebrae have unfortunately been removed to show the cord. 
 Presented by A. White, Esq., 1827. 
 
 277. The skeleton of a Human hydrocephalic foetus with a spina 
 
 bifida involving the dorsal, lumbar, and sacral regions. 
 In this specimen the bodies of the vertebrae are also de- 
 ficient, so that the spine is completely cleft as high as the 
 cervical region. 
 
68 ABNORMAL CONDITIONS OF THE AXIS. 
 
 b. Occipital deficiency. 
 
 278. The skull and vertebral column, with a portion of the ribs and 
 
 the pelvis, of a hydrocephalic male foetus, with distortion 
 of the vertebral column, defective development of the oc- 
 cipital bone, and defective closure of the vertebral canal 
 behind. 
 
 The laminae of the cervical and first six dorsal vertebrae are 
 widely separated behind ; those of the right side are defective. 
 There are apparently but five cervical vertebrae, and their laminae 
 are fused together. The head was pressed back so that the edges 
 of the enormously dilated foramen magnum rest on the edges of 
 the laminae of the dorsal and cervical vertebrae, to which they were 
 attached by ligament. The supraoccipital cartilage bones are very 
 small. There are, however, two scale-like bones representing the 
 upper part of the supraoccipital bounding the foramen magnum 
 above. The frontals and parietals are very large. There is spina 
 bifida in the lumbar and sacral region. The pedicles and laminae 
 are well developed, but they are spread out on either side, so that 
 the spinal canal is open behind. There was talipes of both feet. 
 Presented by J. Hutchinson, Esq., 1870. 
 
 279. An occipital bone with similar deficiency from a Human 
 
 foetus. 
 
 c. Epicephalocele. 
 Syn. Monstres Exencephaliens, Geoff. 
 
 280. A Human female foetus with a large cyst-like tumour in the 
 
 occipital region. The frontal bones are much depressed. 
 The cyst has been opened behind ; the posterior part of 
 the cerebrum protrudes into it. 
 
 281. The head of a Human foetus with a large epicephalocele on 
 
 the vertex. Hunterian. 
 
 Subclass III. Anencephalus. 
 Syn. Monstres Pseudencephaliens et Acephaliens, Geoff. 
 
 In anencephalus the roof of the skull is absent or consists of the 
 membrane-bones pushed forward upon the forehead, where they 
 form a narrow band or crest ; the cartilaginous supraoccipital is 
 always absent, and the whole base of the skull is widely exposed. 
 The neural arches of the cervical vertebrae are more or less open, 
 
MALFORMATIONS OF THE AXIS FROM DISEASE. 69 
 
 they are rarely closed. The brain is usually absent; it is some- 
 times represented by a cyst filled with fluid which protrudes from 
 the occipital region. The condition arises, probably, sometimes 
 at least, from ulceration of the vertex in the embryo. (See No. 
 282.) 
 
 282. A Human male foetus at six weeks, with the brain exposed 
 
 in the occipital region ; a large circular ulcer occupies the 
 occiput. When recent the edges of the ulcer were vas- 
 cular and eroded. The spinal cord and vertebral laminse 
 are deficient in the cervical and upper dorsal region. 
 
 Presented by B. T. Lowne, Esq., 1871. 
 
 283. A Human anencephalous foetus about 2 inches long, with 
 
 entire deficiency of the brain and spinal cord. The bodies 
 of the vertebrae are exposed behind as far as the sacrum. 
 There is curvature of the spine and ectopia of the viscera. 
 Presented by F. Kiernan, Esq., 1871. 
 
 284. A vertical section of the head of a Human female anen- 
 
 cephalous foetus. The roof of the skull and the laminae 
 of the cervical vertebrae are entirely wanting. The brain- 
 membranes, containing some brain-substance and a large 
 clot, form a tumour which projects behind the head. 
 
 Presented by W. Copeland, Esq. 
 
 285. A vertical section of the head of a Human female anence- 
 
 phalous foetus, injected. The roof of the skull is wanting ; 
 the laminae of the first three cervical vertebrae are open. 
 There is no trace of brain, but the base of the skull is 
 covered by a thin vascular membrane. Hunterian. 
 
 286. The other half of the same. Hunterian. 
 
 287. The abdomen of the same opened in front, with the prin- 
 
 cipal viscera removed, to show the much lobulated kid- 
 neys, a condition of arrested development. Hunterian. 
 
 288. A preparation similar to No. 285. 
 
 Presented by Sir W. Blizard. . 
 
 289. The skull and vertebral column of a Human anencephalous 
 
 foetus. The frontals, parietals, and the upper part of the 
 squama occipitalis are very narrow from before back- 
 wards, and these bones are much depressed, so that they 
 lie upon the anterior part of the base of the skull. The 
 supraoccipital is absent, so that the opening is an 
 
70 ABNORMAL CONDITIONS OF THE LIMBS. 
 
 immensely enlarged posterior fontanelle. The exoc- 
 cipitals are very large and perforated by a considerable 
 foramen. The spinal canal is open, the laminae and 
 spines being spread out on either side ; several are an- 
 kylosed together, as are also the three upper ribs of the 
 right side. The bodies of the cervical vertebrse exhibit two 
 lateral centres of ossification, a condition very constantly 
 met with in conjunction with other forms of abnormal 
 development. Mr. Langstaff's Museum. 
 
 290. A male Human anencephalous foetus. 
 
 Presented by John Abbey, Esq., 1826. 
 
 291. A male Human anencephalous foetus with the placenta ad- 
 
 herent to the membranes of the brain. 
 
 Presented by T. M. Donohoo, Esq., 1862. 
 
 292. A female Human anencephalous foetus with ectopia of the 
 
 viscera. The sac containing the protruded intestine has 
 been laid open; a large portion of the placenta is seen ad- 
 hering to the sac. 
 
 These two preparations are interesting, as they show an extremely 
 frequent complication of these conditions. On a priori grounds it 
 would appear extremely likely that the placenta would become 
 adherent to an open membranous surface like the peritoneum, 
 arachnoid, or pia mater, or to the edge of an ulcerating surface like 
 that exhibited by No. 282. It is not a little remarkable that so 
 many have considered such adhesion as the cause of the malfor- 
 mation, as it is far more probably an effect, or an accidental com- 
 plication extremely prone to occur. 
 
 Hunterian. 
 
 SERIES III. 
 
 ABNOBMAL CONDITIONS OF THE LIMBS. 
 
 I. IN INVERTEBRATES. 
 
 293. A small Crab in which the upper nail of the left claw ex- 
 hibits the form of an entire claw, without, however, any 
 joint at its base. Purchased. 
 
VARIATION. 71 
 
 II. IN VERTEBRATES. 
 Class I. VARIATION. 
 
 A. In the number of Digits. 
 
 The number of digits is frequently in excess of the normal 
 number, polydactylism : more rarely fewer are developed ; such 
 specimens have been arranged under the fourth and fifth Classes. 
 
 a. Polydactylus. 
 
 Syn. Perissodactylus, Megalomelus perissodactylus, Ourlt. 
 Several distinct conditions have been arranged under this 
 head*. It has, however, been thought wiser to attempt no 
 division until a much larger collection of specimens can be 
 obtained. Some of these conditions are admitted varieties ; such 
 are the accessory toes of the St. Bernard dog and Dorking fowl : 
 others are probably the effect of fission or dichotomy, either of 
 a single digit, or of several, or even of the entire limb. Some- 
 times the accessory digits resemble adventitious buds, and the 
 supernumerary parts not unfrequently simulate to those of the 
 opposite ]imb. 
 
 294. The foot of a Fowl with the inner toe bearing an accessory 
 
 digit of three phalanges, nearly resembling the second 
 toe of the other foot, on its inner side. The middle toe 
 has also a minute supernumerary nail growing from its 
 last phalanx on the same side. 
 The existence of a supernumerary toe on the inner side of the 
 
 foot is characteristic of the Dorking breed, and is transmitted very 
 
 truly. 
 
 Hunterian. 
 
 295. The skeleton of the other foot of the same bird. 
 
 Hunterian. 
 
 296. The left manus of a Pig, with a small accessory inner toe 
 
 behind the normal one. 
 
 This toe is probably a supernumerary digit added to the nor- 
 mal second digit, and not a thumb, a view amply confirmed by the 
 succeeding preparations. 
 
 Hunterian. 
 
 297. The left maims of a Pig with considerable enlargement of 
 
 * Sec Introduction. 
 
72 ABNORMAL CONDITIONS OF THE LIMBS. 
 
 the second metacarpal bone, which bears a large accessory 
 toe inside its normal digit. The accessory toe simulates 
 the inner digits of the right manus. It cannot be iden- 
 tified with any normal digit. 
 
 Presented by Mr. E. Horniblow, 1872. 
 
 298. The skeleton of the right manus of a Pig, which is almost 
 
 completely double. The accessory parts apparently belong 
 
 to the left side of the body. 
 
 The condition of this manus, as well as the succeeding, is appa- 
 rently identical with that of a human hand described by Jardine 
 Murray (Med.-Chir. Trans, vol. xlvi. p. 29), a photograph of which 
 is preserved in the Museum of the Middlesex Hospital. 
 
 Hunterian. 
 
 299. A similar specimen. Hunterian. 
 
 300. Part of the skeleton of the left manus of a Calf with a 
 
 supernumerary toe on its inner side. The epiphysis of 
 the third metacarpal bone is very broad and is partially 
 divided into two portions, and its shaft is correspondingly 
 broad below. 
 
 301. The manus of a small Horse, with an accessory hoof and 
 
 imperfect digit growing from the inner side of the distal 
 extremity of the middle metacarpal bone. The splint- 
 bones are normal, and there is no evidence to show that 
 the hoof and digit represent the second. As in the 
 above and some of the following cases, it has apparently 
 the characters of a digit from the other manus. The epi- 
 physis of the metacarpal bone is also partly doubled. 
 This foot is described in the Osteological Catalogue as No. 3206. 
 
 Purchased. 
 
 302. The left second and third metatarsal bones of a Horse, with 
 
 excessive development of the second, which ends below 
 in a trochlear extremity for articulation with a digit *. 
 
 303. The right and left third metacarpal bones of the same Horse, 
 
 with a supernumerary second metacarpal of large size, 
 having an inferior trochlear surface for a digit attached 
 to each. An internal splint-bone, however, existed as 
 usual, a fact which can readily be made out from the 
 
 * A similar case of development of a splint-bone in the manus is 
 figured and described by Wood-Mason in the Proc. Asiat. Soe. Bengal, 
 1871, p. 24. 
 
VARIATION. 73 
 
 articular surfaces and general form of the bone, although 
 it has been unfortunately lost. 
 
 304. The skeleton of the right manus of a Horse, with an additional 
 
 largely developed digit intercalated between the inner 
 splint-bone and middle toe. The second row of carpal 
 bones is fortunately preserved, and exhibits an additional 
 bone, probably an os magnum. A great deal of irregularly 
 ossified tissue surrounds both digits. The horse was shod 
 on both toes. Presented by Lawson Tait, Esq. } 1872. 
 
 305. The skeleton of the right manus and pes of a half-grown 
 
 Cat. The manus possesses seven digits ; there are also 
 two trapezoid bones in the carpus, and the proximal ex- 
 tremity of the metacarpal bone of an eighth digit is 
 apparent. The pes has five digits. 
 
 In the manus the digits are arranged in the following order, 
 beginning from the inner side of the hand : A preternaturally 
 slender thumb and a second digit (index), having its ungual and 
 median phalanges like those of a left digit, are articulated with 
 the trapezium and inner trapezoid respectively ; a second thumb, 
 consisting of three phalanges, is attached to the outer side of the 
 index by ligament: a second index with normal right charac- 
 ters follows; its metacarpal bone does not reach the second 
 trapezoid but ends in a point above and is joined by ankylosis 
 to the head of a third metacarpal bone so intimately that it appears 
 at first sight to be a portion of that bone ; no other portion of an 
 accessory third digit exists ; the remaining digits are the normal 
 third, fourth, and fifth. It appears as if the inner side of this 
 manus has been doubled, the accessory toes being reversed and 
 afterwards fused in obliquely behind and inside the normal digits. 
 In the pes the second digit is supplemented by an additional 
 reversed second digit. The middle cuneiform is also double. The 
 inner cuneiform exists, but the normal rudiment of a hallux is 
 absent. 
 
 Presented by B. T. Lowne, Esq. 
 
 306. The left manus and pes of the same animal, exhibiting the 
 
 same malformation, dissected to show the muscles. 
 In the manus a distinct extensor muscle, proprius pollicis, goes 
 to the accessory or inner thumb, and a second similar muscle goes 
 to the phalanges of the accessory index. It has probably been de- 
 tached from its proper thumb, which is extremely minute and has 
 become united with the finger which bears it. There is a flexor 
 brevis pollicis (?) to the same finger. 
 
74 ABNORMAL CONDITIONS OF THE LIMBS. 
 
 The pes has an additional extensor with a single tendon for the 
 supernumerary toe. There is also an additional flexor profundus and 
 a large abducens. It also receives a slip from the superficial flexor. 
 
 The cat from which these specimens were taken was one of a 
 litter of five. All had five or six digits on the pes and six or seven 
 on the manus, with one exception, where the hand was normal. 
 The female parent was also the mother of the probable male parent ; 
 both had six or seven digits on the pes and manus respectively. 
 The same peculiarity has been noticed in others of the breed. 
 The mother is since said to have produced a perfectly normal 
 litter. These animals were born at Kingswood, near Bath. 
 
 Presented by B. T. Lowne, Esq., 1872. 
 
 307. The pelvis and posterior extremities of a small Monkey 
 
 with doubling (dichotomy) of the whole inner side of the 
 left limb. 
 
 The obturator foramen is double and there are two ischial protu- 
 berances. The femur is abnormally thick and has a double trochanter 
 major. There are two tibia3 ; the outer one, being very thin, resem- 
 bles a fibula closely, but an examination of the tarsus at once reveals 
 its true nature. All the bones of the tarsus except the os calcis and 
 astragalus are double. The astragalus is very broad, and exhibits 
 unmistakable marks of partial doubling ; it articulates with two 
 scaphoids, and each of these has its three cuneiforms. An addi- 
 tional cuboid is seen between the two sets of cuneiform bones. 
 All the toes are doubled, except the thumb, and occur in the 
 following order, from within outwards, 1st, 2nd, 3rd, 4th, 5th, 
 2nd, 3rd, 4th, 5th. The median thumb is evidently crowded 
 out, as its cuneiform bone exists. The inner set of cuneiform 
 bones are very much crowded together. All the toes are unmis- 
 takably left digits, none are reversed. 
 
 Hunterian. 
 
 308. The right hand of a new-born Infant, with a supernu- 
 
 merary fifth finger springing from the fifth metacarpal 
 bone. The specimen has been dissected to show the ar- 
 rangement of the tendons. The accessory finger receives 
 the tendon of the extensor minimi digiti, a slip from it 
 going to the normal digit. The accessory finger also re- 
 ceives a slip from the adductor. The infant from which 
 this, together with the two following preparations, was 
 made exhibited several other malformations. See No. 155. 
 Presented by R. Partridge, Esq., 1864. 
 
 309. The left hand of the same Infant, dissected. It presents 
 
VARIATION, EXCESS OF GROWTH. 75 
 
 a very rudimentary accessory fifth finger, attached by 
 ligament only to the metacarpal bone. It has neither 
 tendons nor muscles. 
 
 Presented by R. Partridge, Esq., 1864. 
 
 310. The right foot of the same Infant, with a supernumerary 
 
 outer toe. The specimen is dissected. The fifth and 
 supernumerary toes are equal in size ; both are articulated 
 with a very broad metatarsal bone. The fourth tendon 
 of the flexor longus digitorum splits into two equal parts ; 
 one portion is inserted into the accessory toe. The ad- 
 ditional toe also receives a distinct slip from the tendon 
 of the peronseus tertius. The other foot was normal. 
 
 Presented by R. Partridge, Esq., 1864. 
 
 311. The bones of a Human thumb with dichotomy of the ter- 
 
 minal phalanges. The accessory and normal bones are 
 symmetrically developed, apparently right and left. 
 
 Presented by Dr. Thurnam, 1872. 
 
 312. The skeleton of the left foot of an adult Human female, 
 
 with a supernumerary fourth toe, resembling that of the 
 right foot, between the outer and fourth digits. The ad- 
 ditional toe has a distinct but imperfect metatarsal bone, 
 which is attached to the outer side of the fourth, and 
 wedged between it and the fifth metatarsal bone. There 
 is a cup-shaped cavity at the base of the fifth metatarsal 
 bone, which lodges the base of the accessory bone. 
 
 Presented by Erasmus Wilson, Esq., 1869. 
 
 313. A portion of a Human foot which had six toes. The great 
 
 toe has been removed. The three outer toes are enclosed 
 in a common integument to their extremities. 
 
 Hunterian. 
 
 Class II. DUPLICITY. 
 Arranged in Class I. (see page 71). 
 
 Class III. EXCESS OF GEOWTH (HYPERTROPHY). 
 
 314. Wax models of two Human hands and a foot, with the 
 
 index and middle fingers of the hands and the corre- 
 sponding toes excessively hypertrophied. 
 
76 ABNORMAL CONDITIONS OF THE LIMBS. 
 
 Class IV. ARREST OF GROWTH. 
 
 Although arrest of growth and arrest of development affecting 
 the limbs very frequently occur together, and one is either the 
 result or cause of the other, yet there are certain forms of arrest 
 of growth giving rise to great shortening of the limbs, brachy- 
 melia, which are not accompanied by any obvious arrest of de- 
 velopment. In brachymelia the bones are usually exceedingly 
 well ossified, but there is frequently deformity from irregular 
 contraction of the muscles, as well as great hypertrophy of the 
 subcutaneous tissue. Arrested growth is sometimes confined to 
 the digits, and is more frequent in the forearm and leg than in 
 the arm and thigh. When the whole of the lower limbs is 
 affected, the pelvic girdle is also usually of small size. Arrest 
 of the forearm or leg gives rise to considerable modification in 
 the arrangements of the muscles ; the flexors and extensors of 
 the digits in these cases usually arise from the shaft of the hu- 
 merus or femur. 
 
 A. In the Digits. 
 
 315. The left hind foot of a Pig in which the third digit is 
 
 shortened by arrest of growth. It is worthy of remark 
 that in the Solidungula this is the only functional digit. 
 
 Hunterian. 
 
 316. The other hind foot of the same animal with more con- 
 
 siderable defect of the corresponding toe. Hunterian. 
 
 317. The left hand of a Human infant at birth with considerable 
 
 shortening of the fingers. The ungual phalanges and the 
 nails are much smaller than is normal. The thumb is 
 short and thick, but its terminal phalanx is not abnor- 
 mally defective. The mother had a similar malformation. 
 Presented by R. Partridge, Esq., 1868. 
 
 B. In the Limbs. 
 
 Syn. Nanomelus, Gurlt. 
 Phocomele, Geoff. 
 
 318. A foetal bitch Puppy with extreme shortening of all four 
 
 extremities and arrest of growth in the posterior portion 
 of the trunk. Hunterian. 
 
ARREST OF DEVELOPMENT. 77 
 
 319. A Human female foetus with shortening of all four extre- 
 
 mities. There is a considerable abnormal deposit of sub- 
 cutaneous fat. The child was still-born at the eighth 
 month of pregnancy. 
 
 Presented by William Lyon, Esq., 1825. 
 
 320. A female Human foetus with arrest of growth in the pelvic 
 
 girdle and all four extremities. The left inferior ex- 
 tremity has been dissected. The muscles of the toes 
 and the gastrocnemius arise from the femur immediately 
 below the insertion of the psoas and glutens maximus. 
 A constriction may be seen around the right thumb, which 
 is obviously in the first stage of so-called intra-uterine 
 amputation. Presented by Sir S. Hammick. 
 
 321. The skeleton of a full-time hydrocephalic foetus, with ex- 
 
 treme shortening of the limbs. All the bones are well 
 ossified except the sternum ; its cartilaginous condition is 
 an indication of arrested development. The shrivelling 
 of the cartilaginous epiphyses has much increased the 
 deformity of this preparation. 
 
 Presented by R. Liston, Esq. 
 
 322. The skeleton of a similar foetus with the great arteries 
 
 injected and preserved. The urinary bladder is also 
 attached to the pelvis. 
 
 Class V. AREEST OF DEVELOPMENT. 
 
 Arrest of development is occasionally uncomplicated, as in 
 aschistodactylus, or webbing of the digits. It is more commonly 
 accompanied by atrophy, which is sometimes so complete that 
 no trace of the part remains . S o-called intra-uterine amputations 
 apparently always arise from atrophy. Sometimes a single bone 
 is undeveloped, probably from early arrest and atrophy. 
 
 A. Of the Digits, 
 a. Aschistodactylus, Gurlt. 
 Syn. Syndactylus, Geoff. 
 
 323. The skeleton of the manus of a Pig, with the second pha- 
 langes of the functional digits adherent, and their third 
 
78 ABNORMAL CONDITIONS OF THE LIMBS. 
 
 phalanges fused into a single bone. This condition pro- 
 bably arises from imperfect differentiation of the digits 
 and persistence of the primitive connecting web in which 
 they are formed. Presented by Sir W. Blizard. 
 
 324. The other manus of the same animal ; the functional digits 
 
 are included in a single hoof. 
 
 Presented by Sir W. Blizard. 
 
 325. A precisely similar specimen. 
 
 Presented by Sir E. Homey Bart. 
 
 326. A similar specimen in which the digits are included in a 
 
 single narrow pointed hoof. Hunterian. 
 
 b. Perodactylus. 
 Syn. Ectrodactylie, Geoff. 
 
 ^ 
 
 This condition exhibits arrest accompanied by atrophy. 
 
 327. The hands of a full-time Human foetus. The right is pre- 
 
 pared as a skeleton. The thumb of the left hand is 
 represented by an imperfect terminal joint only; this 
 adheres to the hand by a narrow pedicle of. integument. 
 In the right hand the thumb is entirely wanting, and the 
 fifth digit is adherent to the metacarpal bone of the fourth. 
 The union is ligamentous, and the base of the fifth meta- 
 carpal bone has been entirely absorbed. The process of 
 atrophy seen in progress in these digits is precisely 
 similar to that which affects supernumerary digits. In 
 these the phenomenon is observed far more commonly 
 than in the normal parts. 
 
 Presented by R. Partridge, Esq. 
 
 B. Of the Limbs, 
 a. Ischnomelia. 
 
 Where the limb is preternaturally slender,, some of the bones 
 are frequently absent ; the digits are often arrested at an early 
 stage of development. There is usually arrest of other parts ac- 
 companying this condition. A patagium very rarely remains in 
 arrested conditions of the limbs. See No. 329*. 
 
 * See also Gurlt, Path. Anat. der Haus-Saugethiere, ii. p. 118, and 
 Theil ii. tab. iv. fig. 5. 
 
ARREST OF DEVELOPMENT. 79 
 
 328. A foetal Pig, in which the development of the posterior 
 
 limbs and pelvic girdle has been considerably arrested. 
 The femora are deficient from atrophy, so that the limbs 
 are only attached to the trunk by skin and ligamentous 
 tissue. The abdomen has been opened below to show 
 the extremely diminutive condition of the pelvis and 
 pelvic viscera. The hind legs terminate in blunt points, 
 and each has a very imperfect hoof. Hunterian. 
 
 329. A foetal Puppy, in which the development of all four limbs 
 
 has been arrested. The specimen has been much altered 
 by having been dried previously to being placed in spirit, 
 but is of extreme interest, as it exhibits a very rare con- 
 dition, a patagium extending from the flank to the elbow 
 on either side. Mus. Brit. 
 
 330. The skeleton of a Human foetus, at about the sixth month 
 
 of gestation, with the radii and thumbs wanting. The 
 head is slightly hydrocephalic. All the bones are ab- 
 normally slender, especially the clavicles, which are con- 
 siderably bent. The ossification of the sternum is very 
 irregular and imperfect, as is also that of the pubic sym- 
 physis. Presented by Erasmus Wilson, Esq., 1869. 
 
 331. The skeleton of a Human seven-months' foetus, with total 
 
 deficiency of the right arm. The scapula and clavicle 
 are, however, present. The left arm is represented by a 
 cartilaginous humerus, a slender ulnar, and a single digit, 
 which consists of a metacarpal bone and three phalanges 
 
 XT I: o 
 
 united by cartilage and ligament. 
 
 Presented by Sir W. Blizard, 1811. 
 
 332. A Human male foetus, 7 inches in length, about the fifth 
 
 month of gestation, with the left arm arrested and atro- 
 phied. The arm consists entirely of soft tissues, and has 
 a three-lobed extremity ; one of the lobes terminates in 
 a slender thread-like process. The remains of the limb 
 are attached to the glenoid cavity by connective tissue. 
 The great pectoral muscle ends in the connective tissue 
 of the limb. A portion of the integument has been re- 
 moved to show the conditions described above. 
 
 Mus. Brookes. 
 
80 ABNORMAL CONDITIONS OF THE LIMBS. 
 
 b. Peromelia, Gurlt. 
 
 Syn. Perochirus and Achirus, Gurlt. 
 Hemimele and Ectromele, Geoff. 
 
 When the development of a limb, or a portion of a limb, is 
 arrested and the arrested portion undergoes atrophy a stump 
 is frequently left like that of an amputated limb. The process 
 is apparently the same as that which is seen in a less complete 
 stage in No. 309, 327, and 328. The remains of the atrophied 
 limb are usually apparent as a papilla upon the stump, showing 
 that the ordinary view, that such conditions arise from intra- 
 uterine amputation, is fallacious. Those who suppose the am- 
 putation to arise from ligature by the umbilical cord seem to 
 forget that the cord is a growing structure, and that it is so fre- 
 quently wound around the neck and body that amputations, not 
 only of the limbs but of the head, would be frequent, and slighter 
 effects of such constriction would occur in numerous cases. No 
 definite line can be drawn between the conditions classed under 
 the terms ischnomelia, peromelia, and amelia. Transitional con- 
 ditions are of frequent occurrence. 
 
 333. A Human female foetus, about the fifth month of gestation. 
 
 The left leg is deficient from the knee. It presents the 
 appearance of the stump of an amputation. There is also 
 defective development of the face and left anterior ex- 
 tremity. The left hand at first sight appears to have but 
 three digits, but on closer inspection two of these are 
 seen to be double. The manner in which these fingers 
 are flexed and adhere together throws considerable light 
 upon the condition exhibited by Nos. 352 and 353. 
 
 334. The right leg of a foetus, of which the other three extre- 
 
 mities exhibit the condition known as intra-uterine am- 
 putation (see Nos. 335, 336, 337). Only a single toe is 
 developed. The tibia is represented by a large mass of 
 cartilage, and a small cartilaginous nodule represents the 
 bones of the foot. The leg is much shortened and bent. 
 A section has been made to show the cartilages. 
 Arrest of differentiation of the same kind, affecting only a portion 
 of a segment in the limb, would give rise to fusion of the upper 
 part of the bones in the forearm or leg, either above or below. A 
 very interesting specimen of fusion of the upper part of the radius 
 
ARREST OF DEVELOPMENT. 81 
 
 and ulnar of both arms in an adult is preserved in the museum 
 of St. Thomas's Hospital. 
 
 335. The right arm of the same foetus. The limb terminates 
 
 just below the elbow in a stump like that of an amputa- 
 tion. 
 
 The arm has been divided vertically to show the condition of 
 the internal parts. The humerus is perfect and articulates with 
 a piece of cartilage, which represents the upper extremity of the 
 ulna. The direction of this rudimentary olecranon is such that the 
 forearm, if developed, would be flexed at right angles to the arm. 
 The triceps and brachialis anticus are both seen in section. The 
 skin is stretched tightly over this olecranal cartilage, but it forms 
 a tubercle at its anterior extremity, an exceedingly rudimentary 
 representative of the forearm and hand." 
 
 336. The left arm of the same foetus, in which the upper arm 
 
 ends in a conical stump at the junction of the middle and 
 lower thirds of the humerus. A longitudinal section has 
 been made through it, to show the rounded termination 
 of the humerus and its relation to the integument. A 
 minute cutaneous knot represents the more anterior parts 
 of the limb. 
 
 337. The left inferior extremity of the same foetus. All the 
 
 parts below the condyles of the femur are represented by 
 a minute tubercle only on the outer side of a rounded 
 stump ; and this is formed by the skin, which is stretched 
 tightly over the inferior articular extremity of the femur. 
 The limb has been divided vertically. 
 
 338. A Human full-time foetus, with the inferior extremities 
 
 represented by button-shaped processes, and the position 
 of the superior extremities indicated by minute depres- 
 sions only. The left inferior extremity has been dis- 
 sected ; it is seen to consist of ligamentous tissue, into 
 which numerous irregular muscles arising from the pelvis 
 are inserted. The testes are abdominal, and there is an 
 excessive development of subcutaneous fat. 
 
 Presented by C. J. White, Esq., 1870. 
 
 c. Micromelia. 
 
 This term has been applied to minute undeveloped limbs. 
 Examples are exceedingly rare. 
 
82 ABNORMAL CONDITIONS OF THE LIMBS. 
 
 339. A portion of the left hip of a Wild Boar, with a small pro- 
 
 cess representing the left posterior extremity. The fol- 
 lowing particulars are extracted from Hunter's Manu- 
 script ' Cases and Dissections/ vol. iii. p. 70 : The 
 animal had no kidney on the side, the left testicle had 
 not descended, its epididymis,vas deferens, and vesiculum, 
 as well as the gubernaculum, were entirely absent. The 
 gland itself was rudimentary. The right testicle was 
 normal and situated in the scrotum. Hunterian. 
 
 d. Amelia. 
 
 Where the limbs are totally deficient. In such cases it is 
 impossible to determine- whether the condition arises from primi- 
 tive deficiency of the limb, or from subsequent arrest followed 
 by atrophy. 
 
 340. A Frog with entire deficiency of the right anterior ex- 
 
 tremity. A portion of the integument has been removed 
 to show the complete absence of all traces of a limb. 
 
 Hunterian. 
 
 341. A Chick, with total deficiency of the right inferior extre- 
 
 mity. The inner toe of the left foot is double. 
 
 Hunterian. 
 
 342. A foetal bitch Puppy, with total deficiency of the anterior 
 
 extremities. There is slight arrest of development of the 
 face. Mus. Brit. 
 
 Class VI. MALFORMATIONS FROM DISEASE. 
 
 A. Distortion from irregular muscular contraction. 
 
 The malformations included in this division are probably 
 due to some form of cerebro-spinal irritation or defect. They 
 frequently accompany other abnormal conditions. 
 
 a. Talipes. 
 
 Talipes varus, valgus, calcaneus, calcaneo-varus and -valgus 
 occur as congenital conditions. The question of their origin 
 from irregular muscular contraction is still an open one ; but the 
 arguments in favour of this view are exceedingly strong. The 
 
MALFORMATIONS FROM DISEASE. 83 
 
 subject is discussed at length in Mr. W. Adams's Jacksonian 
 Prize Essay on Club-foot, chapter xii, p. 195 . 
 
 343. The right leg and foot of a Human infant at birth, with 
 
 talipes varus, dissected to show the muscles. 
 
 Presented by W. Adams, Esq., 1864. 
 
 344. A similar preparation. 
 
 Presented by W. Adams, Esq., 1864. 
 
 345. A similar preparation. 
 
 Presented by W. Adams, Esq., 1864. 
 
 345 a. Two Human foetal left astragali. The upper specimen is 
 deformed, and was taken from the foot of a new-born in- 
 fant with talipes varus. The other specimen is normal. 
 Presented by W. Adams, Esq., 1864. 
 
 345 b. The tendo Achillis, tibialis posticus, flexor longus, and 
 
 tibialis anticus tendons of a Child, a year old, that had 
 
 been operated on successfully for club-foot at six weeks. 
 
 The line of junction between the old and new tendon could 
 
 only be traced with difficulty, especially in the tibialis anticus 
 
 and posticus tendons. In the former there seemed to be about 
 
 half an inch, and in the latter three eighths of an inch of new 
 
 tendon. In the tendo Achillis rather more than half an inch of 
 
 new tendon could be recognized. The flexor longus does not 
 
 appear to have been divided. 
 
 Presented by W. Adams, Esq., 1864. 
 
 346. The right leg and foot of an adult Human subject, with 
 
 extreme talipes varus, injected and dissected to show the 
 muscles, vessels, and nerves. The contracted condition 
 of the plantar fascia is well seen. 
 
 347. The right leg and foot of a Human adult with congenital 
 
 talipes varus, dissected. 
 
 Presented by R. Partridge, Esq., 1866, 
 
 348. The left leg and foot of the same subject, dissected, to 
 
 show the bones and ligaments. 
 
 Presented by R. Partridge, Esq., 1866. 
 
 349. The right leg and foot of a Woman, aged 30, with talipes 
 
 varus, dissected and dried. 
 
 This specimen is minutely described in Mr. W. Adams's Prize 
 Essay, p. 163. It is of extreme interest, because there is no 
 doubt about its having been congenital in its origin. 
 
 The oblique position of the os calcis, the vertical deviation of the 
 
84 ABNORMAL CONDITIONS OF THE SKIN. 
 
 astragalus, the lateral position of the navicular bone in respect to 
 the astragalus, the displacement inwards and backwards of the 
 cuboid bone, and the angle of flexion of the anterior portion of the 
 foot from the transverse tarsal joint are well exhibited. 
 
 Presented by W. Adams, Esq., 1864. 
 
 b. Congenital distortions of bones by curvature. 
 
 350. The skeleton of the hind leg of a Rabbit, in which the 
 
 femur is much shortened and curved. During life the 
 animal was unable to use the limb ; it was turned up over 
 its back. Presented by B. T. Lowne, Esq., 1871. 
 
 351. The bones of the arms of a Human subject, with extreme 
 
 contortion of the radius and ulna in both limbs. The 
 carpal extremity of the right ulna is dislocated. 
 
 c. Congenital dislocation. 
 
 352. The phalanges of a distorted Human hand, dislocated and 
 
 adherent to each other, probably by abnormal muscular 
 contractions at an early period. The specimen is im- 
 perfect. Hunterian. 
 
 353. Two of the metacarpal bones and some of the phalanges 
 
 of a similar distorted hand. The specimen is imperfect. 
 
 Hunterian. 
 
 SERIES IV. 
 
 ABNORMAL CONDITIONS OF THE SKIN AND ITS 
 APPENDAGES. 
 
 The specimens classed under this Series are probably all due 
 to variation or congenital diseases. As there are but few of them, 
 and nothing is known of their nature, they have not been further 
 subdivided. 
 
 354. A Fowl which is almost entirely without feathers. It came 
 
 from the egg in this condition and lived seven months. 
 
 Purchased. 
 
 355. A full-grown Mouse without hair on its skin from birth. 
 
 The vibrissse and scales on the tail are normal, and the 
 
ABNORMAL CONDITIONS OF OSSEOUS AND MUSCULAR SYSTEMS. 85 
 
 integument is considerably wrinkled as if from hyper- 
 trophy*. Presented by W. Clift, Esq., 1820. 
 
 356. A similar hairless Rat, killed with a similar Rat in a barn 
 
 near Colchester, Feb. 1, 1872. 
 
 Presented by Dr. Bree, 1872. 
 
 357. The feet of a Golden Poland Cock, five years old, with two 
 
 spurs, one of very large size, on each foot. 
 
 Presented by T. B. Curling, Esq., 1872. 
 
 358. A large horn which grew from the groin of a Ram. 
 
 Hunterian. 
 
 359. The core of the same. Hunterian. 
 
 360. The head of a Cow with a very large horn-like appendage 
 
 growing from the forehead immediately between the 
 eyes. Hunterian. 
 
 361. A portion of the core of the same hollowed into numerous 
 
 cysts. Hunterian. 
 
 362. Another portion of the same. Hunterian. 
 
 363. Another portion of the same. Hunterian. 
 
 SERIES V. 
 
 ABNORMAL CONDITIONS OF THE OSSEOUS AND 
 MUSCULAR SYSTEMS. 
 
 This Class is intended to include all variations from the ordi- 
 nary type in the disposition and arrangement of muscles and of 
 individual bones. 
 
 A. Of the Sternum and Ribs. 
 
 364. The sternum and rib-cartilages of a Human adult, in which 
 
 the cartilages of the eighth ribs are united directly with 
 the sternum, and those of the first and second, on the 
 left side, are fused together. Hunterian. 
 
 365. The cleft sternal extremity of a Human rib. 
 
 366. Two of the left lower ribs of a Human subject, with dicho- 
 
 tomy of their anterior extremities, probably from the 
 same subject as No. 367. 
 
 * A similar condition is described by J. S. Gaskoin as a zoological 
 variety, Zool. Soc. Proc. 1856, p. 38. 
 
86 ABNORMAL CONDITIONS OF THE HEART AND VESSELS. 
 
 367. The first and second right ribs, probably from the same 
 
 subject , united by bone throughout the greater part of 
 their length. 
 
 368. Two specimens of united ribs from a Human subject, one 
 
 from the right and the other from the left side. 
 
 Presented by F. Kiernan, Esq., 1872. 
 
 369. Two similar specimens from a Sheep. 
 
 SERIES VI. 
 
 ABNORMAL CONDITIONS OF THE SENSORY ORGANS. 
 
 A. Of the Eye. 
 
 370. The head of a large Carp, with entire deficiency of the eye 
 
 on the left side. Hunterian. 
 
 371. A Chick at about the tenth day of incubation, in which 
 
 the left eye has suffered arrest at a very early period. 
 The right eye is abnormally large, and the upper beak 
 deviates to the left, so that it crosses the lower one. 
 
 Presented by B. T. Lowne, Esq., 1872. 
 
 372. A Chick about the beginning of the third week, similarly 
 
 malformed. 
 
 373. The right eye of a Sheep, with a dark brown tumour from 
 
 which a lock of wool has grown on the outer edge of the 
 cornea. Presented by J. C. Chaylor, Esq., 1870. 
 
 SERIES VII. 
 
 ABNORMAL CONDITIONS OF THE HEART AND VESSELS. 
 Class I. VAKIATION. 
 
 a. Abnormal arrangement of the vessels. 
 
 374. The thorax of a Human foetus laid open in front, with the 
 arteries injected. The two carotids are given off from a 
 common trunk in the situation of the innominate artery. 
 The left subclavian arises separately, and the right springs 
 
VARIATION. 87 
 
 from the posterior part of the arch of the aorta, and 
 passes behind the oesophagus to its destination. 
 
 From the Museum of Sir A. Cooper, Bart. 
 
 375. A portion of the arch of a Human aorta. The vertebral 
 
 arteries are given off between the innominate and left 
 carotid arteries. The right vertebral is considerably 
 larger than the left. 
 
 b. Situs Mutatus. 
 
 376. A large Human heart with all its parts reversed; there 
 
 was also reversion of all the viscera. The systemic auricle 
 and ventricle are enormously enlarged and hypertrophied. 
 The coronary sinus is largely dilated and receives two 
 large veins. There is no evidence that the hypertrophy 
 and dilatation are due to the malformation. These 
 changes are the results of disease. The spleen in this 
 case was divided into nine separate glands (see No. 390). 
 The specimen is described and figured in the Path, Soc. 
 Trans, vol. xx. p. 93, pi. v. 
 
 Presented by Dr. Hickman, 1871. 
 
 c. In the number of arterial valves. 
 
 Sometimes two or four valves exist at the mouth of the aorta 
 or pulmonary artery. With our present knowledge it is perhaps 
 best to consider these deviations as variations. There is no 
 evidence of dichotomy in cases of supernumerary valves. The 
 condition is not very rare. 
 
 d. Division of the cavity of a ventricle by an adventitious septum. 
 
 This condition is perhaps a very near approach to excess of 
 development. In the following preparation, however, it is 
 apparently due to a variation in the development and position 
 of the columnse carnae. 
 
 377. An adult Human heart with a strong muscular septum 
 
 dividing the apex of the right ventricle into two cavities. 
 The septum terminates in a concave margin between the 
 pulmonary artery and the tricuspid valve ; it apparently 
 consists of united columnse carnse. It is perforated by 
 numerous small openings, between the muscular bundles 
 of which it is composed. Hunterian. 
 
88 ABNORMAL CONDITIONS OF THE HEART AND VESSELS. 
 
 Class V. AEEEST OF DEVELOPMENT*. 
 
 a. Arrested closure of the ductus arteriosus. 
 
 378. The heart of a male Infant, which died with symptoms of 
 
 cyanosis five days after birth. The ductus arteriosus is 
 quite patent. The foramen ovale remains as a slight 
 opening. The heart is abnormally large and weighed 
 1-J- oz. Presented by Dr. Thurnam. 
 
 b. Of the foramen ovale. 
 
 379. The heart of a Child three years old, with a large valvular 
 
 opening in the fossa ovalis. A quill is passed through 
 the opening. Presented by Sir W. Blizard, 1811. 
 
 380. The heart of an Adult with a valvular opening in the fossa 
 
 ovalis. A glass rod has been passed through the open- 
 ing. Presented by Sir W. Blizard } 1811. 
 
 381. A similar preparation. Presented by Sir W. Blizard. 
 
 382. The auricular septum of an adult Human heart, with a 
 
 similar opening in the fossa ovalis. Hunterian. 
 
 383. The auricular septum of an Adult of sixty years of age, 
 
 with a double valvular opening in the fossa ovalis. 
 
 Hunterian. 
 
 c. Of the ventricular septum. 
 
 384. The heart of a lad of thirteen, with both ventricles laid 
 
 open. The septum is deficient above, so that a semilunar 
 opening exists between them. Mus. Heaviside. 
 
 385. An adult Human heart, with a similar semilunar opening 
 
 in the upper part of the ventricular septum, protected by 
 a pouch-like valve of endocardium. The upper edge of 
 this valve is strengthened by a thickened margin, above 
 which there is a semilunar opening between the ventricles. 
 The pouch projects considerably into the right ventricle; 
 it is perforated by several small openings. The outer 
 flap of the tricuspid valve is converted into a similar 
 pouch, which probably covered the septal pouch during 
 the ventricular systole, and partially closed the abnormal 
 opening. Purchased. 
 
 * The other Classes do not occur in this Series. 
 
ARREST OF DEVELOPMENT. 89 
 
 386. A small Human heart, with a semilunar opening at the 
 
 upper part of the ventricular septum. The pulmonary 
 artery has not half its normal calibre. The left auricle 
 and the left auricular ventricular opening are much con- 
 tracted. The mitral valves are very imperfect. The 
 right auricle is enormously dilated, its walls being en- 
 tirely membranous in places. 
 
 The condition of the pulmonary artery and the dilated 
 right auricle point to an imperfect condition of the lungs, 
 with corresponding venous congestion. Unfortunately 
 no history has been preserved. 
 
 387. A Human foetal heart, with the position of its great vessels 
 
 reversed (situs mutatus) . There is no trace of a ventri- 
 cular septum. There is but one auriculo-ventricular 
 opening, with five valves around its margin. There is 
 one large auricle with a small pouch on its right side ; 
 this pouch has an auricular appendix, and obviously re- 
 presents the systemic auricle. The larger left auricle is 
 pulmonary ; but it also receives the superior and inferior 
 cava. 
 
 d. Of an artery (stenosis). 
 
 Is usually accompanied by other abnormal conditions. See 
 No. 386, where there is partial stenosis of the pulmonary 
 artery. 
 
 e. Premature closure of the ductus arteriosus or foramen ovale. 
 This sometimes occurs. It may either be looked upon, like 
 stenosis of the arteries, as a form of arrest, or it may result from 
 disease or from some other malformation. 
 
 f. Of a valve. 
 
 Occasionally one of the flaps of the arterial or auriculo- 
 ventricular valve is arrested and remains rudimentary. This 
 condition is usually accompanied by disease of the valves, warty 
 growths on the endocardium, or even pericarditis. It is pro- 
 bably the result of congenital disease. 
 
 388. A portion of the heart of a Boy ten years of age with two 
 
 of the aortic valve-flaps united into a single flap. The 
 
90 ABNORMAL CONDITIONS OF THE DIGESTIVE ORGANS. 
 
 valves are thickened. There are several wart-like 
 fibrinous growths on the endocardium, and the remains 
 of numerous old pericardial adhesions are apparent. 
 
 Hunterian. 
 
 g. Deficiency of the pericardium. 
 
 Is a very rare form of malformation, which would probably 
 find a place in this Class. 
 
 SERIES VIII. 
 
 ABNORMAL CONDITIONS OP BLOOD- GLANDS. 
 
 A. Of the Spleen. 
 
 The Human spleen normally exhibits a tendency to become 
 lobulated; occasionally the lobules are separated and form 
 accessory spleens, and in some cases numerous small separate 
 glands occur in the place of a single spleen ; division of the 
 spleen is probably a mere variety. 
 
 389. A Human spleen with a small detached lobule on its under 
 
 surface. Hunterian. 
 
 390. Seven, out of nine, small spleens from the same subject as 
 
 the malformed heart, No. 376. The case exhibited com- 
 plete transposition of the viscera ; it is described in the 
 Path. Soc. Trans, vol. xx. p. 93. 
 
 Presented by Dr. Hickman. 
 
 SERIES IX. 
 
 ABNORMAL CONDITIONS OF THE DIGESTIVE ORGANS. 
 
 A. Of the Teeth. 
 
 391. Three specimens of Human incisor teeth adherent in pairs. 
 The lower specimens are the upper and lower milk 
 
ARREST OF DEVELOPMENT. 91 
 
 median incisors ; the upper specimen apparently con- 
 sists of the two median upper incisors intimately united. 
 They are probably all from the same subject. 
 
 Presented by J. Swan, Esq., 1838. 
 
 392. A Human second molar tooth with an inverted tooth 
 wedged in between its fangs. (The inverted tooth is 
 probably the wisdom-tooth, which has been developed on 
 the ascending ramus of the mandible, and which has 
 grown downwards, displacing the fangs of the second 
 molar with its crown and becoming impacted between 
 them.) 
 
 399. The double tusk of an Elephant. 
 
 B. Of the Alimentary Canal. 
 
 Class V. AEREST OF DEVELOPMENT*. 
 
 a. Of the pharynx and oesophagus. 
 
 The pharynx may terminate in a blind pouch, which is either 
 entirely separated from the oesophagus or connected with it by 
 a fibrous or muscular cord only ; in such cases the oesophagus 
 often opens into the trachea, near its bifurcation. 
 
 394. The tongue, pharynx, trachea, and oesophagus of a Human 
 
 foetus, with a small portion of the diaphragm and 
 stomach. The oesophagus opens into the trachea just 
 above its bifurcation; it is not connected with the 
 pharynx. The trachea has been opened in front, and 
 a green glass rod has been inserted into the oeso- 
 phagus. 
 
 395. A similar preparation from a new-born Child, in which the 
 
 lungs and stomach are also preserved. The oesophagus 
 is united with the pharynx by a muscular band. 
 
 Presented by Dr. Ay res. 
 
 396. A similar preparation from a Human foetus ; the lungs are 
 
 abnormal in form, and have not been inflated with air. 
 
 b. Atresia of the rectum. 
 Syn. Atreto cormus, Ourlt. 
 
 One of the most frequent malformations which come under 
 * The other Classes have not occurred in this Series. 
 
92 ABNORMAL CONDITIONS OY THE DIGESTIVE ORGANS. 
 
 the notice of the surgeon is atresia ani, or arrest of develop- 
 ment of the lower extremity of the rectum. 
 
 397. A portion of the rectum of a Child born with an im- 
 
 perf orate anus. It has been considerably distended by 
 the meconium. Presented by Sir W. Blizard. 
 
 398. A similar preparation. Presented by Sir W. Blizard. 
 
 399. The rectum of a female Child nearly two months old born 
 
 with an imperforate anus, for which no operation was 
 performed ; it is much distended, and its muscular coats 
 are hypertrophied. The following note is extracted from 
 Hunter's Manuscript ( Cases and Dissections : ' " Upon 
 examination of the body the large intestines were found 
 very much enlarged and distended, particularly towards 
 the rectum. The jejunum and ileum were slightly in- 
 flamed , the viscera in other respects appeared natural. 
 The colon and rectum contained fluid faeces." 
 
 Hunterian. 
 
 400. The rectum of a Child with imperforate anus ; the last inch 
 
 of the bowel is represented by a fibrous cord only; it is 
 much distended above, and its coats are thickened. 
 
 401. The rectum of a female Child which was born with im- 
 
 perforate anus, in which the operation was performed ; 
 death took place a few hours after. Hunterian. 
 
 402. The rectum of a female Child born with an imperforate 
 
 anus. The operation was performed more than a month 
 before death. Presented by A.C. Hutchison, Esq., 1828. 
 
 403. The rectum of a male Child upon whom the operation for 
 
 imperforate anus was performed with some success. In 
 this instance the trochar had to be introduced three inches 
 before it reached the intestine. The child survived more 
 than ten months. The parts around the artificial opening 
 are much contracted by the action of the spirit in which 
 it is preserved, so that its length is reduced to little more 
 than an inch. The child suffered much from constipa- 
 tion, sometimes for three weeks at a time, and also from 
 a small fistulous opening between the intestine and the 
 urethra ; the urine first became tinged with fseces at the 
 end of three months. The intestine above the structure 
 is greatly dilated and hypertrophied. 
 
 Presented by A. C. Hutchison, Esq., 1823. 
 
ABNORMAL CONDITIONS OF THE URINARY ORGANS. 93 
 
 404. A portion of the rectum of a female Child with a complete 
 
 septum nearly four inches from the anus. This prepara- 
 tion had been dried before it was put into spirit. 
 
 Presented by T. B. Curling, Esq., 1871. 
 
 405. The imperforate rectum of a foetal Pig. Hunterian. 
 
 406. A vertical section of the pelvis of a male foetal Pig, showing 
 
 the viscera in situ. The rectum terminates in a blind 
 pouch; there is no anus. Hunterian. 
 
 407. A similar preparation from a female foetal Pig, in which the 
 
 vagina is also imperforate, and the uterus is largely di- 
 lated with fluid. Hunterian. 
 
 SERIES X. 
 
 ABNORMAL CONDITIONS OF THE URINARY AND 
 GENERATIVE ORGANS. 
 
 Class II. DUPLICITY*. 
 
 Subclass I. Dichotomy. 
 
 Dichotomy affecting the kidney to a greater or less extent 
 occurs comparatively frequently. In the slightest forms the 
 gland only exhibits indications of doubling, which extend in 
 the more marked forms to the pelvis and then to the ureter. 
 Sometimes there are two pelves and ureters. The most marked 
 condition of dichotomy exhibits two distinct ureters opening 
 separately into the bladder ; the kidney has then the appearance 
 of two kidneys fused together. The opposite sides of the body 
 are commonly affected symmetrically, and sometimes the double 
 kidneys of opposite sides extend across the mesial line, and are 
 fused together by their lower edges. 
 
 a. Of the Icidney and ureter. 
 
 408. A small injected, double Human kidney with a double 
 pelvis and ureter ; the ureter becomes single about three 
 inches from the gland. Presented by Sir W. Blizard. 
 
 * No specimens of the first, third, and fourth Classes have occurred 
 in this Series. 
 
94 ABNORMAL CONDITIONS OF THE URINARY ORGANS. 
 
 409. The fellow kidney to the last. The ureters are united 
 
 closer to the gland than in the preceding preparation. 
 
 Presented by Sir W. Blizard. 
 
 410. A double Human kidney and a portion of the urinary 
 
 bladder. There are four ureters, two to each kidney. 
 The left kidney has not been preserved. 
 
 411. A section of a very large Human kidney. The pelvis and 
 
 ureter are double ; they are injected. Hunterian. 
 
 412. A section of a similar kidney. Hunterian. 
 
 413. The lower part of a Human urinary bladder with four per- 
 
 fectly distinct ureters. The orifices of the ureters and 
 seminal ducts are marked by bristles. Mus. Heaviside. 
 
 414. A similar preparation from the same subject as Nos. 411 
 
 and 412. Hunterian. 
 
 415. A similar preparation, in which only one lateral half of the 
 
 bladder has been preserved. Hunterian. 
 
 416. A pair of kidneys from a Human adult, with partial 
 
 doubling of both glands and of their pelves. The glands 
 are united by their lower margins. A portion of the 
 aorta is preserved, and a second set of renal arteries are 
 seen about 2^ inches below the normal vessels. 
 
 417. The kidneys of an adult Human subject with partial 
 
 doubling of both glands, including their pelves. The 
 lower edges of the glands have coalesced across the mesial 
 line. 
 
 418. The lower half of the trunk of a Human foetus with large 
 
 partially double kidneys united by their lower edges 
 across the mesial line. There is an additional renal 
 artery on the right side only. 
 
 Presented by Sir W. Blizard. 
 
 Class V. AEEEST OF DEVELOPMENT. 
 
 A. Of the Kidney. 
 
 419. The kidneys of an encephalous full-time (?) foetus slightly 
 arrested in their development. The lobuli are somewhat 
 more distinct than in the normal kidneys of a seven 
 months' foetus. 
 
ARREST OF DEVELOPMENT. 95 
 
 B. Of the anterior Abdominal wall and Bladder. 
 
 Where there is arrested closure of the abdominal parietes 
 below the umbilicus, and the deficient space is occupied by the 
 urinary bladder. When closure is almost complete, epispadias 
 results : in the more severe forms of this malformation the 
 anterior wall of the bladder is absent, and the posterior portion 
 of that viscus forms a part of the abdominal wall, and projects 
 as a soft rounded tumour, upon the surface of which the ureters 
 open. The symphysis pubis is either deficient or ligamentous, 
 and the penis usually consists of little more than a glans. 
 
 a. Epispadias. 
 
 420. The bladder and generative organs of a Man, aged 22* 
 
 with extreme epispadias ; the bladder is of small size, 
 and opens by an infundibuliform passage above the root 
 of the penis. The penis is shorter than is normal ; it 
 consists of a pair of cavernous bodies surmounted by a 
 rudimentary glans; its upper surface is grooved and 
 covered with mucous membrane. The symphysis pubis 
 is imperfect and ligaraentous. 
 
 Presented by R. Partridge, Esq., 1865. 
 
 b. Ectopia vesicce. 
 
 421. The lower part of the trunk of a Human foetus at about the 
 
 sixth month of gestation, with complete ectopia of the 
 bladder, so that its posterior wall forms a soft rounded 
 tumour, extending from the umbilicus to the root of the 
 penis, which is rudimentary. The ureters open im- 
 mediately above the root of the penis ; their orifices are 
 marked by bristles. The mother was a negress, aged 16 
 years. The foetus was one of twin birth and was 
 still-born. Presented by Dr. R. Sweeting, 1869. 
 
 422. The lower part of the trunk of a small Human foetus with 
 
 complete ectopia of the bladder. The penis is repre- 
 sented by a slight rounded eminence, apparently the 
 glans, with a fold of skin beneath it united to it by a 
 well-marked frenum. There is a slight vertical line im- 
 mediately above the glans, on each side of which are the 
 openings of the prostatic and seminal ducts. The ureters 
 are marked by bristles. The scrotum is well formed ; 
 
96 ABNORMAL CONDITIONS OF THE GENERATIVE ORGANS. 
 
 but the testes have not descended. One kidney is pre- 
 served ; it is much tabulated from arrest of development. 
 Presented by L. J. Beale, Esq., 1829. 
 
 423. The lower part of the trunk of a Human foetus at about the 
 
 sixth month of gestation, with complete ectopia of the 
 bladder. The penis is similar to that of the last prepara- 
 tion. The kidneys and ureters are preserved ; they are 
 much atrophied. The orifices of the latter are marked by 
 bristles. 
 
 424. A Human female pelvis from an adult, aged 39 years. 
 
 The pubic bones are separated from each other to the 
 extent of five inches, and the interval is occupied by a 
 ligamentous band. The woman from which this pelvis 
 was taken was the subject of complete ectopia of the 
 bladder (see next preparation) . The pelvis has evidently 
 been much modified by the manner in which the weight 
 of the body is thrown upon the sacrum, the pubic bones 
 being reduced by atrophy and their symphysis widely 
 separated. Presented by C. Mayo, Esq. 
 
 425. A plaster cast of the bladder and external generative 
 
 organs of the same individual. 
 
 This cast is in the cast-room. 
 
 Presented by C. Mayo, Esq. 
 
 C. Of the Urino-generative Tract. 
 
 The conditions commonly known as hermaphrodism are 
 chiefly dependent on various forms of arrested development of 
 the urino-generative tract. Those which affect the male are 
 classified in the following pages under the terms hypospadias 
 and androgyny, and those which affect the female under the 
 term gynandry. 
 
 Hypospadias is the slightest form of arrest in the urino- 
 generative tract in the male, but no definite line can be drawn 
 anywhere between the slightest degree of hypospadias and the 
 most highly abnormal form of androgyny ; a series of perfectly 
 transitional malformations exist between these extremes. Simple 
 hypospadias consists in the defective closure of the anterior part 
 of the urethral canal below, so that the urethra opens at a dis- 
 tance from the extremity of the penis, although it is continued 
 as an open groove to its normal termination. In those animals 
 
ARREST OF DEVELOPMENT. 97 
 
 in which the penis is contained in a sheath the abdominal in- 
 tegument is united to the penis along the edges of this groove, 
 and the usual retractor muscles are absent. In the most 
 marked forms the scrotum is completely divided into two lateral 
 organs, which in the human subject exactly simulate the -labia 
 of the female. The urethra opens at the base of the penis 
 between the lateral halves of the scrotum. 
 
 In Androgyny the penis is very rudimentary or absent, and 
 the scrotum is cleft. The urethra and sexual orifice are distinct 
 in the human subject ; but in animals this is not usually the 
 case. The sinus pocularis, or male homologue of the uterus, is 
 largely developed and generally has two more or less developed 
 cornua. The vasa deferentia are commonly impervious through- 
 out a considerable portion of their length. The testes ara 
 abdominal or lie in the inguinal canal ; they are usually much 
 atrophied, and probably never exhibit their normal structure. 
 The subjects of this malformation so closely resemble the female 
 externally that it is impossible to determine the sex without 
 dissection. Many forms of gynandrous females resemble normal 
 males far more closely than even slightly androgynous males do. 
 
 In most animals the penis is present, but permanently re- 
 tracted in lateral sigmoid curves, and remains very diminutive ; 
 it is usually entirely concealed in a fold of integument, and 
 strongly resembles a clitoris. In Bulls, where the bulb of the 
 urethra is normally a capacious pouch, it forms the termina- 
 tion of the urino-generative tract, and closely resembles the 
 vagina of the female. Such animals are called " Free Martins " 
 when, as is usually the case, they are twins with perfect males ; 
 they frequently have well-developed teats and much larger mam- 
 mary glands than are normal in the male. The urethral bulb 
 terminates in a solid sexual cord of enormous dimensions ; this 
 cord is always surmounted by a pair of cornua ; sometimes it 
 is perforated by the Miillerian ducts, which run through its 
 entire length and terminate blindly in the cornua. It will be 
 remembered that the Miillerian ducts normally disappear in 
 the male at an early period, but that they persist in the female 
 and form the uterus and Fallopian tubes. This structure is 
 therefore the homologue of the female uterus largely developed. 
 
98 ABNORMAL CONDITIONS OF THE GENERATIVE ORGANS. 
 
 The whole structure of the generative organs of these " Free 
 Martins " is such that, even after dissection, Hunter believed 
 them to be Cows with testes instead of ovaries f. This is not the 
 case ; but cysts (cysts of Morgagni) frequently occur in the peri- 
 toneal fold which embraces the upper extremity of the cornua 
 of the hypertrophied Miillerian ducts, and the epididymis is 
 sometimes separated from the extremely atrophied testis, giving 
 rise to this appearance. The occurrence of these imperfect twin 
 males has given rise to the belief that all female cattle born as 
 twins with males are imperfect : this, however, is not so, as a 
 perfect female is sometimes produced with a male at a birth. 
 There is not, however, any evidence of the existence of andro- 
 gynous Bulls which are not " Free Martins ; " but attention 
 has probably not been paid to this subject. 
 
 Gynandry includes those cases in which the female organs 
 appear like those of the male; it frequently occurs in the 
 human female, and the extent of the malformation is considerably 
 less than in Androgyny. The vagina almost always remains as 
 a narrow canal; but the uterus is commonly well developed. 
 The clitoris attains a very large size and strongly resembles the 
 male penis. In infants it is impossible to distinguish between 
 a hypospadiac male in which the malformation is extreme and a 
 gynandrous female without examining the internal organs. 
 Atresia of the anus sometimes accompanies this malformation, 
 and occasionally the rectum opens into the urino-genital sac, 
 giving rise to a cloaca. 
 
 * In the Human subject J. 
 a. Hypospadias. 
 
 426. A lateral section of a pelvis of a Human male six months' 
 foetus with extreme hypospadias. The urethra opens at 
 the root of the penis ; it is marked by a bristle. The 
 scrotum is deeply cleft ; the left testis is seen in the in- 
 
 t See < The Works of John Hunter,' by J. F. Palmer, vol. iv. p. 34 ; 
 and Hunter's ' Animal (Economy.' 
 
 $ In this Series the malformations of the Human subject have been 
 placed first because they are more readily comprehended by the student, 
 and throw much light on similar conditions in animals. 
 
ARREST OF DEVELOPMENT. 99 
 
 guinal canal ; the right gland is entirely within the 
 internal abdominal ring, and lies in the right iliac fossa. 
 
 b. Androgyny. 
 
 Syn. Pseudo-hermaphroditus, Gurlt. 
 Androgynus, Gurlt. 
 Hermaphrodismes masculins, Geoff. 
 Hermaphrodismes neutres, Geoff. 
 
 427. The lower portion of the trunk of a male child in which 
 the external generative organs so closely resemble those of 
 a female that the child was called " Ellen." The scrotum 
 is very large, completely divided into two halves, so that 
 it forms two labium-like folds of skin ; these are thickened 
 by hypertrophied connective and adipose tissue. The 
 penis is absent ; but a fold of skin strongly resembling the 
 nymphae and clitoris exists in its place : it is probably 
 the prepuce. The urethra and sinus pocularis open by 
 distinct orifices between the lobes of the scrotum. A 
 blue glass rod marks the orifice of the sinus. The urethra 
 is laid open laterally, as is also the lower part of the sinus. 
 The upper part of the sinus is surrounded by prostatic 
 tissue, and it terminates in a pair of cornua, to which 
 the vasa deferentia are attached; these are probably 
 impervious. The testes are abdominal. The bladder 
 and one kidney have been preserved. 
 
 Presented by R. Partridge, Esq., 1865. 
 
 c. Gynandry. 
 Syn. Hermaphrodismes feminines, Geoff. 
 
 428. The external and internal generative organs of a Human 
 
 female foetus. The clitoris is greatly enlarged, and the 
 opening of the vagina is reduced to the diameter of the 
 urethra for more than an inch from its outlet ; beyond the 
 neck of the bladder it dilates to its normal size. The 
 uterus and ovaries are normal. The posterior wall of the 
 vagina has been laid open, and a bristle marks the orifice 
 externally. 
 
 429. The generative organs of a Human female infant. The 
 
 clitoris is very large ; a fold of skin above it represents 
 
 H2 
 
100 ABNORMAL CONDITIONS OF THE GENERATIVE ORGANS. 
 
 the prepuce. The labia are close together below the 
 urethra-like external generative opening : they resemble 
 a scrotum. Externally this foetus could not have been 
 distinguished from a hypospadiac male. The inch and a 
 half of the genital tract common to the vagina and ure- 
 thra is very narrow. Above the neck of the bladder the 
 vagina is normal ; it has been laid open to show the os 
 and cervix uteri. The Fallopian tubes and ovaries are 
 normal. The left round ligament has been preserved ; 
 it ends in the cellular tissue of the labium. 
 
 430. The external organs of generation of a Human female in- 
 
 fant. The vaginal opening is contracted as in the last 
 two preparations. There is a very large clitoris almost 
 embraced by the labia and nymphse, the latter forming a 
 prepuce above the clitoris. . 
 
 There appears to have been an imperforate anus ac- 
 companying the malformation, for which an operation 
 has been performed; this is not, however, recorded. 
 
 Hunterian. 
 
 ** In Animals. 
 a. Hypospadias. 
 
 431. The generative organs of a male Sheep with extreme 
 
 hypospadias. The urethra opens immediately in front of 
 the anus ; but a groove passes forward from this point 
 to the extremity of the penis. The glans penis is small, 
 but is situated in the normal position. The retractor 
 muscles of the penis are absent, and the abdominal in- 
 tegument is united with the edges of the groove on the 
 under side of the penis, as far forward as the glans. The 
 , scrotum is cleft into two distinct sacs ; these are filled 
 with hypertrophied connective tissue. The testes are 
 abdominal. The vesiculse seminales and vasa deferentia 
 open into the urethra. Hunterian. 
 
 432. A similar preparation. The upper part of the bladder, 
 
 vasa deferentia, and all the parts beyond have been re- 
 moved. Hunterian. 
 
 433. A longitudinal section of the extremity of the penis of a 
 
 similar Sheep. Hunterian. 
 
ARREST OP DEVELOPMENT. 101 
 
 434. The generative organs of a Dog with extreme hypospadias. 
 
 The scrotum is bifurcated. There is a large hood-like 
 pouch in front of the imperforate penis, and a median 
 furrow in front of the urethra. The urethra opens close 
 to the anus. The testes are contained in the scrotum. 
 
 Hunterian. 
 
 b. Androgyny. 
 
 435. The generative organs of a small androgynous Dog. The 
 
 testes are abdominal and atrophied. The vasa deferentia 
 are impervious and like fine threads. The penis is im- 
 perforate and very rudimentary. The urinary and sexual 
 outlets are immediately in front of the anus ; they are 
 close together, but distinct. The vasa deferentia are 
 united into a single cord, nearly two inches behind the 
 external orifice *. 
 
 Presented by Sir E. Home, Bart., 1802. 
 
 436. The generative organs of an androgynous Sheep. The 
 
 penis is imperforate and of small size ; it is retracted in 
 lateral sigmoid curves, so that its extremity lies in front 
 of the urethral outlet. The retractor muscles are well 
 developed; the glans is covered by a hood-like sheath. 
 The extremity of the urethra is marked by a blue glass 
 rod. There are four well-marked teats, each with a 
 single gland-duct. The testes are abdominal. 
 
 Hunterian. 
 
 437. The generative organs of a young androgynous Bull. The 
 
 penis is permanently retracted, so that its extremity lies 
 in a sac-like pouch in front of the anus. Hunterian. 
 
 438. The testes of the same animal, imbedded in a mass of sub- 
 
 cutaneous fat above four well-formed abdominal teats. 
 
 Hunterian. 
 
 439. A section of the pelvis of an androgynous Calf, showing the 
 
 generative organs. 
 
 There is a narrow urine-genital pouch, about 4 inches in length ; 
 it is marked by a blue rod. The urethra, marked by a purple 
 rod, opens into this sinus near its outlet. The upper (anterior) 
 extremity of the sinus ends in two cornua, into which the vasa 
 deferentia open. Two small cysts, probably the remains of the 
 
 * Described in Phil. Trans, vol. Ixxxix. p. 157, tab. iv. figs. 1 & 2. 
 
102 ABNORMAL CONDITIONS OF THE GENERATIVE ORGANS. 
 
 upper part of the Miillerian ducts, lie near the extremity of the 
 cornua. The left cornu and part of the corresponding vas has 
 been accidentally destroyed. The right testis is seen under the 
 pubic arch : a section has been made through it to show its struc- 
 ture. The left testis is elongated and atrophied considerably. 
 The vas deferens of the right side is impervious throughout a great 
 portion of its length. A clitoris-like fold at the orifice of the 
 sinus encloses a very diminutive folded penis in a small cyst-like 
 cavity. 
 
 Hunterian. 
 
 440. A section of the pelvis of a Sheep, from the West Indies, 
 
 in which the generative organs closely resemble those in 
 the last preparation, except that the testes are both much 
 elongated and the uterus masculinus (or upper part of 
 the genital pouch) is perforated by two tubes, Miillerian 
 ducts. There are no cysts of Morgagni, or at least they 
 are not apparent *. Hunterian. 
 
 441. The generative organs of a very young Calf, described as a 
 
 " Palmer's Free Martin." They exhibit a highly andro- 
 gynous condition. The large urethral bulb is laid open 
 from above to show the orifices of the urethra and sexual 
 ducts. 
 
 Just within the orifice of the bulb which forms the external 
 opening, and closely resembling the vagina of the female, a slight 
 depression is seen, and immediately beneath this, in the anterior 
 wall of the bulb, is an exceedingly diminutive penis ; it is retracted 
 permanently in sigmoid curves. The neck of the bladder opens 
 into the sinus of the bulb near its upper extremity, and just above 
 it are the openings of the vasa deferentia ; the bulb is prolonged 
 slightly above these, and ends in a thick solid- cord, the sexual 
 cord of the embryo. This terminates above in two solid cornua, 
 an inch and a half in length ; a pair of rudimentary testes are sus- 
 pended in a peritoneal fold at their extremities. The epididymis 
 is much larger than the gland, and this has given rise to the 
 opinion that both ovaries and testes exist : sections have been made 
 through these parts. The microscope shows that the testes con- 
 sist of dense fibrous tissue with cells ; their character is not that 
 of an ovary, but closely resembles the testes usually found in these 
 cases. The vasa deferentia are incorporated with the sexual 
 cord above, but are well formed below, as are also the vesiculse 
 seminales f. 
 
 Hunterian. 
 
 * See Hunter's * Animal (Economy/ p. 60. t Museum Drawings. 
 
ARREST OF DEVELOPMENT. 103 
 
 442. The generative organs of an androgynous Bull. The ani- 
 
 mal was described as ' ' Mr. Arbuthnofs Free Martin " * . 
 
 This preparation is essentially similar to the preceding, except 
 that it is much larger, and the genital cord is perforated by Miiller's 
 ducts ; these have been laid open through their entire length ; they 
 are seen to terminate blindly near the extremity of the cornua. 
 The vesiculae seminales are normal, and the vasa deferentia are 
 developed ; they pass up in front of the genital cord for a short 
 distance, and then lie as convoluted tubes along its outer borders, 
 to the extremity of the cornua ; they terminate in the epididymis. 
 The testes lie close to the extremity of the cornua ; they are very 
 small in proportion to the epididymis, and hence they might easily 
 be mistaken for ovaries. The openings of Cowper's ducts and of 
 the vasa deferentia are marked with purple, and the urethra with 
 a green glass rod. 
 
 Hunterian. 
 
 443. A similar but much larger preparation, from " Mr. Wright's 
 
 Free Martin/' which was five years old f. 
 In this preparation a portion of the bladder has been removed 
 and the spermatic arteries injected. The orifice of the bladder is 
 marked by a blue glass rod ; the openings of the vasa deferentia 
 and Cowper's glands are marked with green rods. The sexual 
 cord in this preparation is quite solid. The testes are situated at 
 the extremity of its cornua ; one is seen in section. Hunter said 
 of them : " I call these bodies testicles, first, because they are 
 twenty times the size of the ovaries of the cow, and nearly the 
 size of the testicles of the bull, or rather those of the ' ridgil,' the 
 bull in which testicles never come down ; secondly, the spermatic 
 arteries are similar to those of the bull, especially of the ' ridgil ' ; 
 thirdly, the cremaster muscle passed up from the rings of the 
 abdominal muscles as it does in the ' ridgil.' Although I call these 
 bodies testes, for the reasons given, yet when cut into they had 
 nothing of the structure of the testicle, not being similar to any 
 thing in nature ; they had more the appearance of disease." On 
 microscopic examination they are found to abound in fibrous tissue 
 enclosing cells, with here and there what appear to be seminal tubes. 
 
 * Hunter's ' Animal (Economy, 5 1st edit. p. 57, pi. i., 2nd edit. p. 71, 
 pi. ix, ; and Museum Drawings. The descriptions of plates ix. and x. in 
 the second edition of the 'Animal (Economy' are transposed and 
 wrongly numbered. 
 
 t Hunter's Animal (Economy/ 1st edit. p. 59, pi. ii., 2nd edit, 
 pp. 64 & 71, pis. viii. & x. ; and Museum Drawings. 
 
104 ABNORMAL CONDITIONS OF THE GENERATIVE ORGANS. 
 
 Hunter adds : " The animal had four teats, but the glandular part 
 of the udder was small." 
 
 Hunterian. 
 
 444. A similar but much smaller preparation, described as " Mr. 
 
 Wells's Free Martin"*. 
 
 The vesiculse and their ducts, as well as the terminal portion 
 of the vasa deferentia, are normal. Cowper's glands are present, 
 and there is a rudimentary penis retracted in sigmoid curves. The 
 sexual cord is solid, as are likewise its cornua. There is only a 
 trace of an epididymis on the left side ; but the cornua of the sexual 
 cord ends in a large thick-walled cyst : the vas deferens on this 
 side is deficient in several places. On the right side there is no 
 trace of a vas or epididymis, and a small oval body, more like an 
 ovary than a testis, exists in the place of the testis ; it consists of 
 tissue, however, which, on microscopic examination, appears iden- 
 tical with that of which the imperfect testes of these malfor- 
 mations usually consist ; there is no reason to regard it as other- 
 wise than an imperfect testicle. There is much fat in the neigh- 
 bourhood of these rudimentary sexual bodies. The animal from 
 which this preparation was taken was a "Free Martin." The 
 following history is given by Hunter in his ' Animal (Economy': 
 " It was between three and four years old, and had never been 
 observed to show any signs of desire for the male, although it went 
 constantly with one. It looked/, more like a heifer than Free 
 Martins usually do. The teats and udder were small, compared 
 to those of a heifer." 
 
 Hunterian. 
 
 c. Gynandry. 
 
 445. A section of the pelvis of a Puppy, with a cloaca common 
 
 to the rectum and urino- generative pouch. The sex is 
 uncertain; but the appearance of the glands is more 
 like that of ovaries than of testes. 
 
 There is a large sinus with two cornua beyond the opening of 
 the bladder, but no trace of vas deferens, vesiculse, or penis. 
 There is no uterus, properly so called, and no vagina. The mi- 
 croscopic structure of the genital glands is more like that of an 
 ovary than of an abnormal androgynous testis. In their immature 
 state and extremely fibrous condition, however, it would be im- 
 possible to assert with any degree of certainty that the animal was 
 either a modified male or female. 
 
 * 'Animal (Economy,' 2nd edit. p. 64, pi. xi. 
 
ARREST OP DEVELOPMENT. 105 
 
 d. 
 Syn. Hermaphrodisme bisexuel, Geoff. 
 
 Although there is no evidence that true hermaphrodism is an 
 arrest of development, it has been thought advisable, in the 
 absence of all knowledge as to its nature, to place it in the same 
 series as those remarkable conditions known as Androgyny and 
 Gynandry, with which it appears to have some connexion. 
 
 True hermaphrodism is not uncommon as a malformation 
 amongst unisexual Invertebrates. Sometimes one side of the 
 body is male and the other female; this is the usual form 
 amongst insects. Another form of true hermaphrodism has 
 been frequently observed amongst fish, in which a portion of 
 one or both ovaries is differentiated into a test is. The following 
 preparations are of this kind : 
 
 446. The ovaries and external generative aperture of a Codfish 
 
 injected. A large piece of convoluted testicle is inti- 
 mately connected with the wall of the right ovisac, in the 
 middle of its outer margin. It is uncertain whether the 
 seminal ducts in this case open into the ovisac ; but in a 
 precisely similar case described by Dr. J. A. Smith* there 
 were five distinct ducts perforating the ovisac and open- 
 ing into the cavity of the ovarium. 
 
 Presented by W. Lynn, Esq., 1825. 
 
 447. A similar preparation, in which the posterior end of the 
 
 left ovary is united with a convoluted mass of testicle 
 almost equalling the ovary in size. 
 
 Presented by Sir A. Carlisle, 1821. 
 
 448. A similar preparation, but not injected, in which a portion 
 
 of convoluted testicle is attached to the anterior end of 
 the left ovary. The testis is about half as large as the 
 ovary. The right ovisac has been opened to show the 
 tufts of ova. Presented by Sir E. Home, Bart., 1802. 
 
 449. The ovaries of a Fish, probably a small Cod, with a very 
 
 small convoluted mass of testes attached to the anterior 
 extremity of the right ovary. Mus. Brit. 
 
 * Journal of Anatomy and Physiology, 1870, p. 256. 
 
106 ABNORMAL CONDITIONS OP THE GENERATIVE ORGANS. 
 
 D. Of the Uterus, 
 a. Double uterus. 
 
 The Miillerian ducts in some animals (the Didelphia) remain 
 distinct,, in others partially distinct, forming the uterine cornua; 
 or they unite to form the cavity of the uterus,, their distinct 
 ends forming the tubes, as in Man. Sometimes in the latter 
 the union either fails partially or entirely, giving rise to a 
 corniculate or double uterus. The vagina is also divided by a 
 septum in extreme cases. 
 
 450. The uterus of a Cow, in which there is a partial septum 
 
 below the cornua. The body of the uterus contains a 
 single cavity, from which the deformed immature fetus 
 No. 261 was taken. There are two cervices and a 
 double os. Hunterian. 
 
 451. The vagina and internal generative organs of a Human 
 
 adult female. The vagina is completely divided by a 
 strong muscular septum. The uterus is double, and 
 each lateral half is quite separate from the other ; they 
 have been bent over laterally in making the preparation. 
 There is a single tube and ovary to each uterus. The 
 cavity of the vagina and uteri are laid open. 
 
 Presented by T. Wormald, Esq. 
 
 452. The orifice of the vagina of a Human adult female; it is 
 
 divided by a strong muscular septum, commencing im- 
 mediately above the urethra. The right nympha forms 
 a free process posteriorly, as if it had been dissected 
 from its attachment. 
 
 453. A double Human uterus and vagina. One of the lateral 
 
 uteri contains a full-time foetus; the other cavity is 
 considerably developed, measuring 4 inches in diameter. 
 The vagina is completely divided by a septum. The 
 bladder, the right side of the vagina, and both uterine 
 cavities are laid open. There is but a single Fallopian 
 tube to each uterus. Hunterian. 
 
 Sometimes one lateral half of the uterus is undeveloped, 
 uterus unicornis ; sometimes the os or the vagina is occluded. 
 It is uncertain whether such malformations should properly be 
 included in the present Class. . 
 
ABNORMAL CONDITIONS OF THE OVA OF BIRDS. 107 
 
 b. Atresia of the os. 
 
 454. A section of a Human adult female pelvis, with the internal 
 generative organs in situ. The uterus is very much en- 
 larged ; it is prolapsed, and lies in the curve of the sacrum. 
 The os was occluded, and an operation was performed, 
 but the patient died. The uterus contained a quantity 
 of offensive fluid. The right ovary is diseased and con- 
 tains large cysts filling the right iliac fossa. There are 
 traces of bloot-clot in the peritoneal cavity. 
 
 Presented by T. PFormald, Esq. 
 
 SERIES XI. 
 
 ABNORMAL CONDITIONS OF THE OVIDUCT AND OVA OF 
 
 BIRDS. 
 
 A. Of the Oviduct. 
 
 455. The sacrum of a young Fowl with the right oviduct per- 
 
 sistent. It forms a large thin-walled cyst, which was 
 distended with air. The left oviduct was normal ; it has 
 been removed, but its orifice is indicated by a bristle. 
 
 Presented by W. B. Tegetmeier, Esq. 
 
 456. The oviduct and ovary of a small Hen, which during life 
 
 laid eggs about the size of a Pigeon's, consisting exclu- 
 sively of albumen, covered by a very perfect shell. One 
 of the eggs is seen in the abdominal opening of the ovi- 
 duct. The oviduct is so small that it could not grasp 
 and transmit the yelks. The ovary is loaded with well- 
 developed ova. When the abdomen was opened the 
 peritoneal cavity was found to be full of the yellow fluid 
 contents of the yelks, which had escaped. The egg which 
 is now in the open extremity of the oviduct was found in 
 the abdominal cavity ; another was situated in the cloaca. 
 As the egg found in the abdominal cavity had undergone no 
 change, it appears probable that it passed back into the abdominal 
 cavity when the Fowl was killed ; it was therefore replaced in the 
 extremity of the oviduct, to show how it must have passed into 
 
108 ABNORMAL CONDITIONS OF THE OVA OF BIRDS. 
 
 the peritoneal cavity. It appears that as each yelk was matured 
 it fell into the abdomen, and was ultimately absorbed, whilst the 
 oviduct poured out albumen and formed a shell, as it would if the 
 yelk had passed into its tube. The Hen, when killed, was ap- 
 parently perfectly healthy. Specimens of the eggs are preserved 
 in No. 467. 
 
 Purchased, 1871. 
 
 B. Of the Ova. 
 a. Twin Eggs. 
 
 In these two yelks or two perfect Chicks are enclosed in a single 
 shell. Double-yelked eggs seldom produce two Chicks. Twin 
 Chicks are probably produced from single-yelked eggs. For 
 further remarks on these conditions see page xix. 
 
 457. The egg of a domestic Fowl with two yelks. The shell is 
 
 well formed, and the egg is larger than the normal size. 
 A portion has been cut away to show the interior. 
 
 Hunterian. 
 
 458. A similar specimen. Hunterian. 
 
 459. The egg of a domestic Fowl containing one Chick. A twin 
 
 Chick escaped from the egg ; both birds were then alive. 
 The one now in the egg, however, died immediately. 
 
 Presented by W. D. Oliver, Esq. 
 
 460. The egg of a Fowl containing two distinct and perfect 
 
 Chicks. The alantois and yelk appear to have been single. 
 
 b. Of the coverings of the yelk. 
 
 Inflammation of the oviduct gives rise to deficiency of the cal- 
 careous covering of the egg, and to a fibrinous condition of the 
 albumen. In some cases, from causes at present unknown, the 
 shell-membrane is the seat of calcareous deposit. 
 
 461. The shells of three eggs, in which the shell-membrane is 
 
 the seat of calcareous deposit. 
 
 462. The shell of a Hen's egg, in which the small pole of the 
 
 albumen was prolonged into a short spiral and covered 
 with shell. It is probable that this specimen is due to 
 disease in a minor degree, similar to that which produced 
 the following abnormal eggs. 
 
 Presented by Dr. F. R. Fairbank. 
 
EGGS WITHOUT YELKS. 109 
 
 463. A Hen's egg, invested in a strong fibrous shell-membrane, 
 
 but without any shell. The albumen is drawn out into 
 a long twisted process at one pole of the egg. A section 
 has been made through the albumen to show its fibrinous 
 condition. Presented by Sir A. Carlisle, 1818. 
 
 464. A similar specimen, in which both poles of the egg are 
 
 prolonged. Presented by W. Clift, Esq., 1811. 
 
 465. Two Hen's eggs without shells, but with a thick shell- 
 membrane, exhibiting small spots of calcareous deposit 
 
 on the surface, united by a narrow pedicle. Hunterian. 
 
 466. A similar specimen. 
 
 Presented by W. B. Tegetmeier, Esq., 1867. 
 
 c. Pseudo-Eggs, or Eggs without yelks. 
 
 467. Pseudo-eggs laid by the Hen the oviduct and ovaries of 
 
 which are preserved in preparation No. 456. The eggs 
 consist of normal albumen enclosed in a small but well- 
 formed shell. 
 
 468. A small, elongated, curved, pseudo-egg from a Fowl, pro- 
 
 bably deformed by abnormal contractions of the oviduct. 
 Presented by W. S. Pocklington, Esq., 1860. 
 
 469. The shell of a similar pseudo-egg. 
 
 470. The imperfectly calcified egg-shell of a similar egg. 
 
 471. Two small pseudo-eggs, formed of concentric masses of 
 
 fibrinous albumen and united by a long pedicle; they 
 are without shells. Sections have been made through 
 them to show their structure. 
 
 472. The egg of a Bantam Hen, with two small masses of albu- 
 
 men, which have descended upon it in succession, covered 
 with shell, and united by calcific deposit to its upper 
 extremity. 
 
 d. Included Eggs or Pseudo-Eggs. 
 
 Sometimes a small egg, or pseudo-egg, remains in the oviduct, 
 or, according to Mr. Tegetmeier, is carried back from the shell- 
 secreting into the albumen-secreting portion of the oviduct, and 
 becomes invested with a second layer of albumen and a second 
 shell ; or it is met by and invested in a second ovum ; in this 
 
110 ABNORMAL CONDITIONS OF THE OVA OF BIRDS. 
 
 way one egg becomes included in another. Very frequently the 
 included egg is cracked or broken ; in such cases impaction is 
 probably the cause of the phenomenon. 
 
 473. The shell of a normal Hen's egg, enclosed in a larger very 
 
 thin shell. The inner shell is cracked, and appears 
 to have been cracked within the oviduct. The space 
 between the outer and inner shells probably contained 
 albumen only, poured out under the irritation of the 
 cracked and impacted egg. 
 
 474. A similar specimen. 
 
 475. A smaller egg-shell included within a larger one ; both 
 
 shells are perfect. An opening has been made in the outer 
 one. Presented by Dr. Birch) 1857. 
 
 476. The shell of a Goose's egg, containing that of a second 
 
 egg ; both shells were perfect : the outer shell has been 
 fractured. Presented by Dr. Leach. 
 
 477. A small well-formed pseudo-egg, which was found within 
 
 another egg. Hunterian. 
 
 e. Fibrinous masses from the Oviduct. 
 
 When an egg is broken or otherwise impacted in the oviduct, 
 it may become surrounded by fibrinous layers, and these often 
 form a mass of very large size. 
 
 478. An immense fibrinous mass, containing a broken egg, from 
 
 the oviduct of a Hen. A section has been made to show 
 the composition of the tumour. 
 
 Presented by W. B. Tegetmeier, Esq., 1871. 
 
 479. A section of a similar fibrinous mass, containing a broken 
 
 egg. Presented by W. B. Tegetmeier, Esq., 1871. 
 
169 
 
 OSTEOLOGICAL MUSEUM OF THE EOYAL 
 COLLEGE OF SURGEONS. 
 
 The wayfarer, on journeying from the " City " towards the 
 " West end," may occasionally pass through Lincoln's Inn Fields, 
 and will find on the south side a large building, with handsome 
 portico in front, which is well known to the world, but more espe- 
 cially to those who practise the healing art, as the Royal College 
 of Surgeons of England. 
 
 The first institution of the kind which occupied this spot, and 
 was finished about the commencement of the present century, was 
 from unforeseen causes obliged to be almost wholly removed, and 
 in 1835-6 the present far nobler structure erected, under the able 
 superintendence of Mr. (now Sir Charles) Barry. Within this 
 building, which occupies a very considerable area, are a series of 
 lofty, well-proportioned rooms, devoted to the actual business of 
 the College, which consists principally in the examination of those 
 young aspirants for the honours and emoluments of a laborious 
 and anxious profession who, with a very laudable motive, wish to 
 prove to the public that they have been so far zealous in their 
 studies as to have gained the privilege of adding to their names 
 the well-known title of M.E-.C.S.E., which will be found a suffi- 
 cient guarantee of their fitness for practice in every part of the 
 globe where surgery is regarded as a science. This portion of the 
 building contains the council-room, in which the affairs of the 
 College and of the surgical profession generally are managed by 
 twenty-four of the most enlightened and experienced members of 
 the profession. 
 
 There are also two most valuable Libraries, one seventy feet 
 in length, and containing upwards of forty thousand volumes de- 
 voted to medical and surgical subjects, the other of smaller size, 
 and occupied principally by works on Comparative Anatomy, Zoo- 
 logy, and Botany. There are also two Theatres, in which lectures 
 
170 OSTEOLOCIICAL MUSEUM. 
 
 are delivered, one of these being specially fitted up for the exhibi- 
 tion of specimens by the microscope ; but the crowning glory of 
 all is the unrivalled Hunterian Museum, in which are deposited 
 those vast treasures which have contributed more to the advance- 
 ment of Comparative Anatomy and Physiology in this country 
 than any other scientific collection. 
 
 The Museum, as it now stands, consists of three rooms, the 
 largest of which, containing the recent Osteological collection and 
 the Physiological series in spirit, is depicted in the accompanying 
 plate. Of the other two, it may briefly be stated that of the larger 
 (91 feet in length, 39 in breadth, and 35 feet in height) the floor 
 is devoted to the exhibition of the hard and more durable parts of 
 plants and invertebrate animals, to the skeleton of man, the crania 
 of the different races of men, to the illustration of those parts 
 of the skeleton affected with injury and disease, to vascular prepa- 
 rations, and lastly, to the several modes employed in past and pre- 
 sent times for the preservation of the dead. The galleries are occu- 
 pied by morbid parts displayed in spirit. The smaller room contains 
 the fossils, of which are arranged a wonderful series, collected by 
 John Hunter, and only lately exhibited to the public in the wall- 
 cases ; whilst on the floor are the gigantic Megatherium, Mylodon, 
 and Dinornis, which have been so ably restored and described by 
 our British Cuvier, Professor Owen. These two rooms for se- 
 veral years contained not only the Hunterian Collection, but all 
 the additions made to it both by donation and purchase since it 
 was entrusted to the College of Surgeons ; but becoming so 
 crowded, and a favourable opportunity occurring for securing 
 some adjoining premises, these were purchased at the cost of 
 16,000, and on the spot where once stood the theatre of D'Ave- 
 nant, in w r hich Betterton and Garrick nightly performed before 
 crowded audiences, was erected the large room represented in our 
 stereograph, in which are deposited the greater part of the trea- 
 sures accumulated through a long and anxious career by the im- 
 mortal Hunter. This room is 100 feet in length, 40 in breadth, and 
 45 feet high. On the floor are arranged in zoological order the ske- 
 letons of some of the larger mammalia, amongst which, in the fore- 
 ground on the left, may be readily seen the Walrus, with his bold 
 forehead and dependent tusks j then follow the Horse, Hippopo- 
 
172 OSTEOLOGIOAL MUSEUM. 
 
 various classes of beings. The digestive organs occupy the next 
 place; then follow the absorbent, circulating, respiratory, and 
 nervous systems, the organs of the senses ; and lastly, the connec- 
 tive and tegumentary systems. The second division includes the 
 series of organs devoted to the preservation of the species, show- 
 ing also the gradual development of the young. Attached to the 
 rails of both the galleries in this Museum are long glass cases, in 
 which are arranged such specimens, preserved in a dry state, 
 as serve to render the Physiological series more complete. In 
 these cases will be found a large collection of vascular prepa- 
 rations and wax models ; amongst the latter may be seen the 
 beautiful specimens of the entire anatomy of the Torpedo, dis- 
 sected and prepared by the celebrated Professor Calamai, of Flo- 
 rence, for the Grand Duke of Tuscany, by whom they were pre- 
 sented to Professor Owen, and by him to the College. 
 
 Such is a brief outline of the arrangement of the subjects con- 
 tained in the two galleries of this magnificent room, numbering 
 now altogether upwards of seven thousand specimens, nearly five 
 thousand of which were collected and displayed by that extraor- 
 dinary man who will ever be regarded as the founder of the true 
 system of Comparative Physiology. 
 
OSTEOLOGICAL MUSEUM. 171 
 
 tamus, and Rhinoceros ; whilst on the right are the Antelope, Ox, 
 Elk, Camel, and overtopping all, the Giraffe ; and in the centre, 
 immediately behind the bust of the illustrious Founder, stands 
 the elephant Chunee, for many years an inhabitant of Exeter 
 Change. In the wall-cases the smaller skeletons are exposed to 
 view, and in the table-cases on the floor the individual bones en- 
 tering into the formation of the skeletons, both large and small, 
 are arranged in "long, long rows." From the roof are suspended 
 two skeletons, both belonging to the Whale tribe ; the one which 
 forms the most prominent feature in the stereograph is the Bi- 
 dent Dolphin, or Bottle-nosed "Whale. It was caught in the 
 Thames in 1783, and is described and figured by Hunter in the 
 * Philosophical Transactions.' The other skeleton, of which only a 
 portion of the tail is seen in the figure, is a young specimen of 
 the Piked Whale, also alluded to by Hunter in the paper above 
 quoted. In the corners of this room are large dried preparations 
 of the Heart of the Whale, Elephant, and Dromedary, with their 
 principal blood-vessels injected with wax, and standing in a line 
 with the two rows of the skeletons. On pedestals are glass 
 cases containing some of the smaller skeletons, and one exhibiting 
 a remarkable series of specimens illustrating the growth of the 
 Salmon, from the egg until it arrives at a fish upwards of fifteen 
 pounds in weight. In the case on the opposite side are beautiful 
 models in wax of the development of the Tadpole of the common 
 Frog, showing the wonderful changes that take place in the yelk 
 prior to the formation of the embryo within. 
 
 The Physiological series, in spirit, the great work of Mr. 
 Hunter's life and the great glory of this country, standing as it 
 does unrivalled, occupies the galleries. This series embraces dis- 
 sections of the organs of plants and animals, classed according to 
 their different vital functions, each series commencing with the 
 most simple, and passing onwards to the most complex form of 
 organ. The first division consists of those organs necessary for 
 the preservation of the individual, and commences with a few ex- 
 amples illustrating the component parts of organic bodies, such as 
 sap, blood, etc. ; then follow the organs of support and motion, 
 and then the various means by which progression in the water, 
 through the air, and on land, are successively accomplished by 
 
 168200 
 
DEC 1 7 1993 
 
U.C.BERKELEY LIBRARIES 
 
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