V ANIMAL AUTOMATISM 225 



mounts up with great care and deliberation, put- 

 ting first one leg forward and then another, until 

 he balances himself with perfect precision upon 

 the edge ; and if the turning of the hand is 

 continued, he goes through the needful set 

 of muscular operations, until he comes to be 

 seated in security, upon the back of the hand. 

 The doing of* all this requires a delicacy of co- 

 ordination, and a precision of adjustment of the 

 muscular apparatus of the body, which are only 

 comparable to those of a rope-dancer. To the 

 ordinary influences of light, the frog, deprived of 

 its cerebral hemispheres, appears to be blind. 

 Nevertheless, if the animal be put upon a table, 

 with a book at some little distance between it 

 and the light, and the skin of the hinder part of 

 its body is then irritated, it will jump forward, 

 avoiding the book by passing to the right or left 

 of it. Therefore, although the frog appears to 

 have no sensation of light, visible objects act 

 through its brain upon the motor mechanism of 

 its body. 1 



It is obvious, that had Descartes been acquainted 

 with these remarkable results of modern research, 

 they would have furnished him with far more 

 powerful arguments than he possessed in favour 

 of his view of the automatism of brutes. The 



1 See the remarkable essay of Goltz, Beitragc zttr Lehrs 

 von den Functionen der Ncrvencentren des Froeches, published 

 in 1869. I have repeated Gbltz's experiments, and obtained 

 the same results. 



VOL. I Q 



