NATURE 



;«5 



THURSDAY, AUGUST 24, 1882 



TEXT-BOOKS OF ANATOMY 

 Tfandtruch der Vergleichenden Anatomie. Leitfaden bet 



Zoologischen uttd Zootomischen Vorlesungen. By Prof. 



E. ( scar Schmidt. Eighth edition, pp 327. (Jena, 



1882.) 

 Lehrbuch der Vergleichenden Anatomic der Wirbelthiere 



auf Grundlage der Entwickelungsgeschichte. By Prof. 



Rt. Wiedersheim. First part, pp. 476. (Jena, 18S2.) 



IT is now thirty-three years ago since Oscar Schmidt, 

 then a young Privat Docent, published the first 

 edition of his " Handbook of Comparative Anatomy" as 

 a guide to his course of lectures. Successive generations 

 of students have called for successive editions, until in 

 the present year the author is in the enviable position of 

 issuing the eighth edition of his Handbook, and he ha s 

 added to its value by now for the first time illustrating it 

 with upwards of 100 well executed woodcuts. It would 

 be out of place, and indeed quite unnecessary, to enter 

 into a detailed criticism of a work, so well known as the 

 present, and which has obviously supplied a want felt by 

 so many students. As regards the general motive of the 

 book we may say that it presents an outline of the com- 

 parative anatomy both of the Invertebrata and Vertebrata, 

 written in a clear style and methodically arranged. 



He classifies animals into eight groups : Protista and 

 Protozoa, Ccelenterata, Echinodermata, Vermes, Arthro- 

 poda, Mollusca, Tunicata, Vertebrata. This classifica- 

 tion will scarcely commend itself to the more ardent 

 members of that school of zoologists, which bases taxo- 

 nomy on embryology ; and which considers no system of 

 classification is of value unless it expresses the path that 

 has been taken by animals in the course of their evolu- 

 tion. By these zoologists Prof. Schmidt's system will 

 without doubt be regarded as old-fashioned. But it has 

 the merit of simplicity, and this from the student's point 

 of view is no slight recommendation. Moreover, taxo- 

 nomic systems, more especially of the Invertebrata, 

 based on supposed phylogenic relations, are as yet mere 

 speculations. They have their value, no doubt, as group- 

 ing together certain ascertained facts, and as suggesting 

 new directions for investigation. But they are in the 

 main quite hypothetical, and without such fixity of know- 

 ledge as will give them permanent value. 



There is one point in the classification of the Mammalia 

 followed by Prof. Schmidt, to which we must take very 

 decided exception. We refer to the adoption of the 

 placenta as a dominant character in the subdivision of 

 the Monodelphia. Milne- Edwards, Huxley, Haeckel, 

 and Carus have all undoubtedly attached much import- 

 ance to this organ in taxonomy, but from the fuller know- 

 ledge that we now possess, both of its form in various 

 mammals and of the mode in which it is shed during 

 parturition, it is clear that its characters are not of such 

 primary value as to outweigh, in framing a system of 

 classification, those furnished by the other organic sys- 

 tems. In placing the Prosimii (Halbqffen) amongst the 

 DeJditata, Schmidt has committed a similar error to that 

 into which Haeckel has also fallen. For the Lemurs, 

 whose placentation has been carefully studied both by 

 Vol. xxvi. — No. 669 



Alphonse Milne-Edwards in Paris and by W. Turner in 

 Edinburgh, are unquestionably as adeciduale as a mare, 

 a pig, or a whale. In the lemurs, as in thesi animals, 

 the villi are diffused over the greater part of the sur- 

 face of the chorion, and the sac of the allantois is 

 relatively large. The evidence, therefore, is altogether 

 opposed to retaining them in the position in which 

 Schmidt has placed them amongst the deciduata. Again, 

 he ranks the Edentata in the Adeciduata, but there is no 

 uniformity in the character of the placenta in this order 

 of mammals. In Manis undoubtedly it is non-deciduate 

 and diffused ; in Orycteropus it is broadly zonular ; whilst 

 in the Sloths it is deciduate and composed of numerous 

 discoid lobes. 



Prof. Wiedersheim's Lehrbuch differs from that of Prof. 

 Schmidt in being limited to the comparative anatomy of 

 the Vertebrata. It is a new candidate for public favour, 

 and as yet only the first part has been published. In this 

 part, after a short general introduction, the author treats 

 in succession of the integument, skeleton, muscular, and 

 nervous systems, including the organs of sense and 

 electrical apparatus of the several classes of vertebrates- 

 The modifications in the form and arrangement of the 

 different systems are examined, therefore, rather in their 

 anatomico-physiological than in their zoological aspects. 

 By limiting himself to one only of the great divisions of 

 the animal kingdom, the author has been enabled, within 

 the compass of a volume of moderate size, to enter much 

 more fully into the consideration of the several systems 

 than was possible in Prof. Schmidt's treatise, and he has 

 produced a work which, when completed, will be of 

 service to those students who desire a fuller acquaintance 

 with the details of vertebrate structure. For students of 

 Human Anatomy this book will have a special interest, 

 as the subject is treated so as to throw great light on the 

 modifications of structure met with in other vertebrates 

 when compared with man. The author indeed appears 

 to have had in his mind, in planning out the work, the 

 needs of students of medicine ; and he has been desirous 

 of giving to their anatomical training a wider and more 

 philosophic range than it frequently possesses. The 

 teaching of anatomy in our medical schools is unfor- 

 tunately too much entrusted to men whose main object in 

 life is the practice of surgery, and who follow anatomy 

 for a time merely as a training for that practice. It 

 becomes therefore in their hands a dry specialty. The 

 varied and complex structures of the human body are 

 regarded almost exclusively as parts which are liable to 

 disease and injury, and which may require surgical inter- 

 ference, whilst the marvellous beauty of their physio- 

 logical and morphological relations is ignored. When 

 human anatomy is taught from a scientific, and not from 

 a mechanical point of view, it becomes a medium for the 

 exposition of the great facts and principles of develop- 

 ment and morphology, and its value as an educational 

 instrument is enormously increased. 



We can recommend Prof. Wiedersheim's " Lehrbuch," 

 both to students of medicine and to their anatomical 

 teachers, as a work in which they will find a clear and 

 concisely written description of the great facts of verte- 

 brate structure ; by the perusal of which much that may 

 seem obscure in the construction of the human body will 

 be illuminated, and great additional interest will be im- 



