388 Appendix C 



teresting and suggestive, especially as contrasted with the recent 

 psychological theory of Mr. H. R. Marshall. In the present 

 theory, the ' self-exhibition ' of which Mr. Marshall makes so 

 much, enters as the need of impressing others with the play 

 illusion. As to the hedonic element and its ground, however, 

 the two theories are in sharp contrast, and that of Groos seems 

 to me, on the whole, more adequate. In the wealth of literary 

 reference in his book, Mr. Marshall pays singularly little attention 

 to the authors from whom Groos draws, and none to the earlier 

 work of Professor Groos himself, but treats the play theory 

 only in the form of Mr. Spencer's surplus energy construction. 

 To Groos' theory, musical art would present difficulties and so 

 would lower sensuous aesthetic effects generally. 



Genetically art rests upon play, according to Herr Groos, 

 in that the three great motives of art production, ' Self-exhibi- 

 tion ' (Selbstdarstettung)) ' Imitation,' and ' Decoration ' (Aus- 

 schmuckung), are found in the three great classes of animal 

 plays, respectively, ' Courting,' ' Imitation,' and ' Building Art ' 

 (Baukunste, seen in birds' nest-building, etc.). On the strength 

 of this, Groos finds both aesthetic appreciation and impulse in 

 the animals, and all rests upon the original ' experimenting ' im- 

 pulse. Of this, however, Professor Groos does not give a satis- 

 factory account. Experimenting is a necessary part of effective 

 learning by ' imitation,' I think, and the use made of it in the 

 selection of movements may be its original use. 



On the whole, Professor Groos' book is both a pioneer work 

 and one of great permanent value. It contains a good index 

 and a full list of the literary sources. 



III. 



Habit and Instinct. By C. Lloyd Morgan, F.G.S. London and 

 New York, Edward Arnold. 1896. pp. 35 1. 1 



Professor Morgan's Habit and Instinct adds another to his 

 series of works, now three in number, dealing with comparative 

 psychology. The reader is impressed anew with the prime 



1 From The Nation, May 13, 1897. 



