July 27, 1906.] 



SCIENCE. 



113 



the classification of the amphibia with special 

 reference to the common American forms and 

 their habits. The second is one of the most 

 interesting of all and considers in some three 

 dozen pages the life and habits of this common 

 frog; recounting its methods of locomotion 

 and of feeding; describing its voice, enemies, 

 parasites, as well as its breeding habits and 

 its responses to changes in temperature, etc. 



The succeeding two chapters briefly describe 

 the exterior of the frog and the main features 

 of its internal structure, reserving for later 

 chapters detailed descriptions of anatomy and 

 physiology. The fifth chapter devotes some 

 38 pages to the embryology of the frog from 

 the time the egg is laid through the meta- 

 morphosis into the adult shape, and includes 

 a brief historical introduction. Chapter six 

 presents a brief outline of vertebrate histology 

 as illustrated in the frog, while chapter seven 

 takes up the digestive organs rather fully, 

 with special emphasis upon glandular activity. 

 The eighth chapter deals with organs of voice 

 and of respiration from a physiological stand- 

 point and leads to the ninth chapter, which is 

 devoted entirely to the skin, an undue amount 

 of space being devoted to its color changes. 



The excretory organs and the reproductive 

 organs each receive a chapter descriptive of 

 their anatomy and functions. 



The devotion of an entire chapter to the 

 subject of internal secretions is timely and the 

 restriction of the treatment of the skeleton to 

 a single chapter of fifteen pages shows com- 

 mendable restraint, considering the large 

 amount of detail that might so readily have 

 been retained here. 



From the point of view of the student the 

 ten pages devoted to the muscles might well 

 have been made fewer. 



The fifteenth chapter describes the micro- 

 scopic structure of the blood, the anatomy and 

 action of the heart, the distribution of the 

 veins and arteries and the circulation as seen 

 in the web of the foot, with also a brief con- 

 sideration of the lymph system. 



The sixteenth chapter gives a good descrip- 

 tion of the anatomy of the nervous system 

 and considers reflex actions and the conflict- 

 ing evidence as to the functions of the various 



parts of the brain : so that 35 pages are needed. 



The structure and uses of the sense organs 

 are adequately treated of in some 20 pages. 



The last two chapters deal with the in- 

 stincts, tropisms and intelligence of the frog 

 as known from the works of Yerkes, Parker 

 and others. Probably the pr^entation given 

 will give the student a just conception of the 

 rather confused and tentative nature of the 

 results thus far gained by the experimental 

 study of the psychology of the frog. 



The author has prepared the book as the 

 outcome of six years of lectures given to stu- 

 dents who had studied some general biology. 

 As a compilation it gives the gist of the anat- 

 omy and histology of Gaupp's ' Ecker,' and 

 enough of the embryology of Marshall and 

 deserves great praise for bringing together in 

 attractive form much of the scattered knowl- 

 edge of the natural history and physiology of 

 the frog. To be commended is the list of 

 authors at the end of each chapter and the 

 impression conveyed that the conclusions 

 reached in the physiology and psychology of 

 the frog are complex balancings of diverse 

 facts and opinions while suspended judgment 

 is often imperative. 



The 94 illustrations are, with few excep- 

 tions, the familiar figures of Ecker, Howe and 

 Marshall and while one need not expect many 

 illustrations for a physiological presentation 

 of the subject yet one could wish that the 

 excellent photographs used as a frontispiece 

 might have been followed by others illustra- 

 ting the natural history of the frog. 



While the book is easily read and the au- 

 thor's meaning clear, some hypothetical stu- 

 dent punctilious as to English but ignorant of 

 natural history, might be misled in reading 

 of the feeding habits of the toad, page 14: 

 ' angleworms are seized by the jaws and stuffed 

 into the mouth by the fore legs.' 



Every teacher of vertebrate zoology will 

 need a copy of the book and many college 

 students will find it a valuable text-book. But 

 while the central idea of adding physiology 

 and natural history to anatomy and embryol- 

 ogy is a good one, it almost necessarily leads 

 to putting too much knowledge before the 

 student. In a second edition, for which we 



