518 SCIENCE PROGRESS 



same Phylum we encounter the introduction of another element, termed by 

 the author a " protoneurone," interpolated between the receptor and the muscle 

 cells. It is the appearance of this third element that renders possible the 

 development of the central nervous system in both Invertebrate and Chordate 

 types. In this final type we find that the central nervous system serves as an 

 adjustor. 



The nervous systems of higher animals are also dealt with to some extent, even 

 including a brief indication of the main characteristics of that of the Chordata. 



The book is well written and, as will be seen from the foregoing brief summary 

 of its contents, one of great importance in all work dealing with the experimental 

 investigation of the behaviour of the lower animals. In addition, it is a distinct 

 contribution to our knowledge, both of the function and structure of the lower 

 organisms, and presents another and fresh aspect of our conception of the nature 

 of nervous control in animals. It should find a place in the library of all 

 biologists. 



C. H. O'D. 



MEDICINE 



The Human Skeleton: an Interpretation. By Herbert Eugene Walter, 



Associate Professor of Biology, Brown University. [Pp. xv + 214, with 



175 illustrations.] (New York: The Macmillan Company, 1918. Price 



10s. net.) 



Although its title would seem to indicate that this is merely another book 



dealing with human osteology, it is in reality both something more and something 



less than a text-book for medical students. After discussing the evolution of the 



vertebrate skeleton, the author proceeds to describe, very briefly it must be 



confessed, the individual bones of the human skeleton and to outline their 



morphology. Written throughout in an attractive manner, the book contains 



many delightful and unexpected expressions, such as the summary of the different 



characters assumed by the tail (p. 78). 



It is important, however, that a book of this type, written principally for the 

 lay public, should avoid the possibility of creating misconceptions, and, in this 

 respect, the book cannot be said to be without fault. Such statements as " the 

 human arm is a foreleg which has become emancipated from the work of loco- 

 motion and support," and "nor are defensive outriggers, like horns, any longer 

 necessary, because the swinging arms take the place of such organs of defence," 

 can only give to the layman the erroneous impression that some unnamed hoofed 

 and horned monster stands in the direct line of man's ancestry. It may, further, 

 reasonably be feared that the frontispiece, which is described in the preface as 

 graphically expressing the motif of the book, will be interpreted as meaning that 

 the human skeleton is an adaptation of the skeleton of the horse or vice versa. 



Further, one expected to find more frequent references to pala^ontological 

 zoology, particularly in the sections dealing with the evolution of the limbs and 

 limb-girdles. 



Despite these omissions and blemishes, the book may be heartily recom- 

 mended to all who, for any reason whatsoever, are interested in human anatomy. 

 It would be especially interesting to the thoughtful medical student after he has 

 completed a year's dissections, for by that time he has forgotten much of his 

 biology, and has acquired an interest in the human skeleton which few books, 



of convenient size, do anything to satisfy. 



T. B. J. 



