394 Literary Notices. 



those facts of structure, function and behavior with which the student of biology 

 should be familiar. 



Chapters are devoted in order to the systematic position, habits, natural history, 

 parasites, external and internal characters, development, histology, the anatomy 

 and physiology of the various systems of organs, the reflexes, instincts and intelli- 

 gence of the leopard frog, Rana pipiens. 



Dr. Holmes has shown good judgment in the selection of his materials from the 

 great mass of literature on the frog. There are many omissions, some of which 

 were necessitated by the limitations of the volume, which are unfortunate from 

 certain points of view, but on the whole the book is well balanced and promises to 

 stimulate students to research while at the same time presenting them with the pre- 

 eminently important facts concerning the biology of the frog. 



There are several minor typographical errors and some verbal omissions which 

 slightly mar the work. The most serious errors noticed by the reviewer occur on 

 p, 331, in the description of the structure of the retina. The passage referred 

 to reads, "The retina is marked by a thickening or papilla where the optic nerve 

 enters, whereas in the higher animals this place is marked by a depression, the 

 fovea centralis." There are two mistakes in the sentence: it certainly is not true of all 

 the higher animals, if of any of them, that the point of entrance of the optic nerve, 

 the blind spot, is marked by a depression. In the human eye there is an elevation, 

 as in the eye of the frog. Further, the fovea centralis is the center of the macula 

 lutea, not the center of the blind spot. Such errors as these are exceedingly 

 unfortunate. 



The chapter on the functions of the brain leaves one with the impression that 

 after all not much is definitely known about the subject. Forthe elementary student 

 this has both advantages and disadvantages: on one hand it shows him that there 

 is plenty of opportunity for original work even in fields of investigation which have 

 been occupied by many skilled scientists, and on the other it tends to make him 

 feel that too little is known about the subject to enable one to study it to advantage. 



Excellent descriptions of many of the commonly observed forms of behavior of 

 the frog are given. It is noticeable, however, that the author has no very definite 

 usage for the word instinct, for on the same page (305) he writes of the clasping 

 reflex and the clasping instinct, while in a later chapter he explains briefly that the 

 instinctive act is probably a chain-reflex. The danger is that a student will be 

 perplexed by the accounts of reflex and instinctive forms of activity which are given. 



The book is provided with convenient author and subject indices and with lists 

 of references at the end of each chapter. Undoubtedly the value of the work could 

 be greatly increased by certain changes in the arrangement of materials and in 

 expression, yet there can be no doubt that it will be very valuable as a text-book. 

 The author deserves much credit for bringing together into readable form the mass 

 of material which constitutes "The biology of the frog." 



R. M. Y. 



Peckham, G. W. and E. G. Wasps Social and Solitary. Boston, Houghton, Miflin and Com- 

 pany. 1905. Pp. sv -)- 311. 



A considerable portion of the material of this volume is revised from the authors' 

 book on the instincts and habits of the solitary wasps," but enough new observations 



'On the Instincts and Habits of the Solitary Wasps. Wisconsin Geological and Natural History 

 Survey. Series No. I, Bulletin No. 2. 1898. 



