7,y8 Appendix C 



II. 



Die Spidc der Thiere. By Karl Groos, Professor of Philos- 

 ophy in the University of Giessen. Jena, Gustav Fischer. 

 1896. pp. xvi + 359. {The Flay of AfWfzals, Eng. trans, 

 by Eliz. L. Baldwin. Appletons, 1898.)^ 



In this volume Professor Groos makes a contribution to three 

 distinct but cognate departments of inquiry — philosophical 

 biology, animal psychology, and the genetic study of art. 

 Those who have follow^ed the beginnings of inquiry into the 

 nature and functions of play in the animal world and in chil- 

 dren wall see at once how much light is to be expected from a 

 thoroughgoing examination of all the facts and observations 

 recorded in the literature of animal life. This sort of examina- 

 tion Professor Groos makes wdth great care and thoroughness, 

 and the result is a book which, in my opinion, is destined to 

 have wide influence in all these departments of inquiry. 



I cannot take space for a detailed report of Professor Groos' 

 positions. It may be well, therefore, before speaking of certain 

 conclusions which are to me of special interest, to give a resume 

 of the contents of the book by chapters. Chapter I. is an 

 examination of Mr. Spencer's ' surplus energy ' theory of Play ; 

 the result of w^hich is, it seems, to put this theory permanently 

 out of court. The author's main contention is that play, so far 

 from being ' b3''-play,' if I may so speak, is a matter of serious 

 business to the creature. Play is a veritable instinct, true to 

 the canons of instinctive action. This view is expanded in 

 Chapter II., where we find a fine treatment in detail of such 

 interesting topics as imitation in its relation to play, the inheri- 

 tance of acquired characters apropos of the rise of instincts, 

 the place and function of intelligence in the origin of these 

 primary animal activities. This chapter, dealing with the 

 biological theory of play, is correlated with Chapter V., later 

 on in the book, in which the * Psychology of Animal Play ' is 



1 From Science, Feb. 26, 1897. Portions of this notice were incorporated 

 in the present writer's preface to the English translation. 



