278 NATURE AND MAN. 



&quot; feet precision upon the edge, and if the turning of the hand is 

 &quot;continued, over he goes, through the opposite set of operations, 

 &quot; until he comes to be seated in security upon the back of the 

 &quot; hand.&quot; 



Even this we are fully justified in attributing to the action of 

 a mechanism : for we are continually ourselves making yet more 

 elaborate adjustments of our muscular movements, to perform 

 some action which originally voluntary has come to be &quot; me 

 chanical ; &quot; and this under circumstances which forbid the idea 

 that the conscious will in any way directs those adjustments. I 

 have already pointed out this in the case of ordinary walking ; 

 and the balancing power of a practised rope-dancer would seem, 

 from the feats which he performs, to be exerted scarcely less auto 

 matically. So in that most entertaining and suggestive book, 

 &quot;The Autobiography of Robert Houdin, Conjuror,&quot; the author tells 

 us that he early in life trained himself to the performance of a 

 number of his feats of dexterity, whilst reading a book with 

 continuous attention ; and that he thus gradually acquired the 

 power of keeping four balls in the air, without a moment s distrac 

 tion of his thoughts. And he further tells us that having a mind, 

 while writing this passage of his memoir, to try to what extent 

 he retained this power, after a disuse of it for thirty years, he 

 found that he could still keep up three bails without any interrup 

 tion of his reading. The purely automatic nature of an action 

 performed under such circumstances, fully justifies our attributing 

 it to a nervo-muscular mechanism ; but there are these essential 

 differences between the automatism of Goltz s frog or of Flourens s 

 pigeon, and that of Houdin that while the one was original, the 

 other was acquired ; and that while the one was set going by an 

 external stimulus, the other was put in action by a conscious 

 intention, of which we have every reason to regard the cerebrum 

 as the instrument. 



Of these differences it appears to me that Professor Huxley 

 has lost sight, in his application to man of the conclusions he 

 draws from the automatism of animals. In refusing to credit the 

 spinal cord of the frog with the power of conscious self-direction, 

 which a few physiologists still attribute to it, he takes his stand 

 (quite rightly, as I think) upon the facts of human experience; 



