56 THE PLAY OF ANIMALS. 



lutely deny it. Similar opinions are held by James, 

 Virchow, Meynert, His, Ziehen, 0. Fliigel, Wallace, 

 Kay-Lankester, Thiselton Dyer, Brooks, Baldwin, Van 

 Bemmelen, Spengel, and many others.* A. Forel has 

 also joined their ranks. f He says: "I, too, used to be- 

 lieve that instincts were hereditary habits, but I am 

 now convinced that this is an error, and have adopted 

 "Weismann's view. It is really impossible to suppose 

 that acquired habits, like piano playing and bicycle rid- 

 ing for instance (these are certainly acquired), could 

 hand over their mechanism to the germ plasm of the 

 offspring." J 



The transition to the idea of instinct is easy at this 

 point, for, even according to the latest formulation of 

 Weismann's theory, it is quite impossible that the intel- 

 ligent actions of ancestors should be transmitted to their 

 descendants as instincts. Even if a modification of the 

 hereditary substance should take place it would not 

 originate in the intelligent act, but in the external con- 

 ditions that impelled the individual to perform the act. 

 Let us take Schneider's example of fear in the dark. 

 Our ancestors frequently encountered in the dark the 

 terrible cave bear. This repeated experience most prob- 

 ably produced in their brains an acquired sensory motor 

 tract: " Dark — be wary! " Now, is it at all conceivable 



* W. James, The Principles of Psychology, 1891, vol. ii, p. 678. 

 Th. Ziehen, Leitfaden der physiologischen Psychologie, 1893, p. 12. 

 0. Fliigel, Ueber das Seelenleben der Thiere, Zeitschrift fur exacte 

 Philos., vol. xiii (1885), p. 143 ; Ueber den Instinct der Thiere mit 

 besondere Rucksicht auf Romanes und Spencer (1890), ibid., p. 17. 

 A. R. Wallace, Darwinism. Baldwin, American Naturalist, June, 

 July, 1896. For the other authors see Weismann's Das Keim- 

 plasma, p. 519. 



f [As has Lloyd Morgan. See his Habit and Instinct.] 



% A. Forel, Gehirn und Seele, 1894, p. 21. 



