60 THE PLAY OF ANIMALS. 



ponents. Many of the cases cited with that in view are 

 scientifically unreliable, and the rest can be explained 

 quite well by the principle of selection. Tf acquired 

 characters were hereditary, what an instinctive predis- 

 position there would be for such acts as writing, for in- 

 stance! — and Spencer would be able to ascribe Mozart's 

 precocious musical talent to the practice of a few previ- 

 ous generations! It should further be borne in mind 

 that the long-continued experiments of Weismann and 

 others have never produced a positive instance of such 

 transmission. Darwin himself was interested in the 

 question. Eomanes tells us that in 1874 he had a long 

 conversation with him on the subject, and undertook a 

 systematic series of experiments under his direction. He 

 continued them for more than five years almost uninter- 

 ruptedly, but they were all unsuccessful; so he, too, 

 found it impossible to establish the truth of the inherit- 

 ance of acquired characters.* 



As regards instinct, there is, further, the a priori 

 argument that it is inconceivable how acquired connec- 

 tions among the brain cells could so affect the inner 

 structure of the reproductive substance as to produce 

 inherited brain tracts in later generations. And, finally, 

 there is this consideration mentioned by Ziegler as a 

 suggestion of Meynert's: "It is well known that in the 

 higher vertebrates acquired associations are located in 

 the cortex of the hemispheres. As an acquired act be- 

 comes habitual, it may be assumed that the correspond- 

 ing combination of nervous elements will become more 

 dense and strong and the tract proportionally more 

 fixed. This being the case, it follows that the tracts of 

 acquired and habitual association, as well as those of 



* Romanes, A Critical Examination of Weismannism, preface. 



