Literary Notices. 97 



is no other general principle even formally adequate at hand, and further that he is 

 quite cognizant of the fact that in our present state of knowledge of the phenom- 

 ena of behavior the explanation of evolution in this field given by natural selection 

 is a purely formal and artificial one. 



Chapter XX deals with the question of consciousness in lower organisms in a 

 highly interesting way. The conclusion reached is that: "All that experiment and 

 observation can do is to show us whether the behavior of lower organisms is objec- 

 tively similar to the behavior that in man is accompanied by consciousness. If this 

 question is answered in the affirmative as the facts seem to require, and if we further 

 hold, as is commonly held, that man and the lower organisms are subdivisions 

 of the same substance, then it may perhaps be said that objective investigation is as 

 favorable to the view of the general distribution of consciousness throughout ani- 

 mals as it could well be. But the problem as to the actual existence of conscious- 

 ness outside of the self is an indeterminate one; no increase of objective knowl- 

 edge can ever solve it. " 



The final chapter has for its heading " Behavior as regulation, and regulation in 

 other fields." The importance as a general regulatory principle of the selection 

 from a variety of activities, those lines of activity which lead to a minimum inter- 

 ference with the physiological processes of the organism, together with the preserva- 

 tion or fixation of adaptive activities through the law of the readier resolution of 

 physiological states, is emphasized. This chapter has been published elsewhere in 

 essentially its present form. 



A bibliography and index complete the volume. The book is very completely 

 and well illustrated. 



On the whole, one finds very little in the book to criticise. Undoubtedly there 

 are many who will not fully agree with Jennings in some of his interpretations and 

 conclusions, but technical discussion of views opposed to those of an author falls 

 properly within the scope of the special memoir, not that of the review. He who 

 searches this book for errors in statement of fact or of principle, or for evidence of 

 deficient knowledge of what has previously been done in the field covered, or for 

 slips in logic or diction, will spend his time fruitlessly. One fault of omission 

 should be corrected in a later edition. Throughout the book there is no indication of 

 the scale to which the figures are drawn, and hence there is no way for one not already 

 familiar with the organism discussed to know anything about their relative sizes. 

 Of course this matters not at all to the biologist, but as things stand at present, the 

 "lay" reader of the book must inevitably go away with the impression that Chilo- 

 monas is a veritable giant among Protozoa altogether surpassing in size the mediocre, 

 not to say diminutive, Bursarta. This, however, is a matter of detail. In general 

 one has only praise for the book. It is a contribution of a high order of merit to 

 biological literature. It is valuable to the specialist as a careful and thorough sum- 

 mary and digest of the present state of knowledge in the field of which it treats, and 

 as a unified setting forth of the author's matured opinions regarding the broader 

 aspects of the problems of animal behavior. To the general reader it presents an 

 authoritative, clear and most interestingly written account of a side of natural his- 

 tory which has hitherto, for the most part, lain entirely outside his ken. We heartily 

 wish for it the large circulation which it certainly deserves. 



RAYMOND PEARL. 



