REVIEWS. 



The Treatment of Disease, a Manual of Practical Medicine. By Reynold 

 Webb Wilcox, M. A., M. D., LL. D. Cloth. Pp., xxviii+911. Price $6. 

 Philadelphia: P. Blakiston's Son & Co., 1907. 



Comparative Anatomy of Vertebrates. Adapted from the German of Dr. Ro- 

 bert Wiedersheim by W. N". Parker, Ph. D. Third edition, founded on the 

 sixth German edition. With three hundred and seventy-two figures and a 

 bibliography. Cloth. Pp. xii + 576. Price $3.75 net. New York: The 

 Macmillan Company, 1907. 



The scope of this work is limited to what is signified in its title, and 

 the subject is treated tersely and clearly from the standpoint of evolu- 

 tion. After the introduction, which gives a synopsis of the early stages 

 of development in general, the different systems are presented briefly 

 with definitions of terms beginning with the integument followed by the 

 skeleton, muscles, etc. ; then each system is described as found in 4m- 

 phyoxus, in fishes, in amphibians, in reptiles, in birds and in mammals. 

 The arrangement is simple and convenient for students in its use as a 

 text book. Many excellent, well-selected drawings increase its effi- 

 ciency. A ready index and a bibliography add to its value as a reference 

 work, although meager in details and too brief to be of great value 

 to investigators. The style is clear and limpid, concise and pointed 

 as a rule, but there are obscure passages that need reconstruction, as for 

 example on page 122, beginning with line 2. "The cranial cavity has 

 become further enlarged at the cost of parts formerly situated extracra- 

 nial^ than is the case among Eeptiles." 



The emphasis placed on evolution necessitates ontogenetic and phylo- 

 genetic details and paleontological records that force the question as 

 to the reason for many striking similarities of extinct forms to existing 

 ones, and of these to each other in both the development of the individual 

 and of the race. Is this similarity to be explained by evolution, or is it 

 only a matter of the same laws controlling development, so that in one 

 this development reaches beyond the point of its cessation in others, thus 

 leaving traces of the early stages as rudiments, vestiges, degenerations, 

 etc.? The latter explanation is as plausible and workable as the 

 former, and does not require "blood relationships of animals in general" 

 as a factor. 



The treatment of the segmentation of the ovum is crude and simple. 

 It might have been improved by a few plates illustrating the various 

 steps of cell cleavage by mitosis. 



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