A Limit to Evolution 295 



1)thmg of anatomy, but simply sets going the wonderful 

 echanism of his body, and this works out the result for 

 '■^ him. In the first place the various parts of his eyes must be 

 adjusted to see the mark distinctly. Then his body must 

 be held in a certain position, and for this a multitude of 

 nervous and muscular co-ordinations are necessary. The 

 stone must be grasped with a certain strength, the arm 

 thrown back to the due extent, and its muscles contracted, 

 in co-ordination with the organ of sight, and with just that 

 degree of vigour, as his fingers are relaxed, which shall carry 

 the stone as desired. Different feelings accomipaiiy these 

 actions — feelings of activity, passivity, touch, tension, etc. — 

 and these feelings guide the action of his body as if it were 

 a sort of automatic sensitive machine. 



Thus we have, apart from the action of the intellect, a 

 power of so regulating our various bodily movements as to 

 produce an harmonious co-ordination, in which a number of 

 subordinate movements are co-ordinated to produce a more 

 general movement in obedience to sensuous impulses. That 

 these complex and orderly combinations may take place 

 without intellectual action and from sensuous impulses only, 

 is plain from the fact that many idiots and sleep-walkers 

 perform them. Even with respect to ourselves, we may set 

 our bodily organism going in a certain direction, and then 

 give up the mind entirely to other matters, so that we walk 

 on, ' lost in thought,' till we are startled at finding we have 

 reached — or it may be overshot — our destination, without 

 having once thought about our journey on the road. But 

 the remarkable power we have of co-ordinating our motions, 

 in response to associated sensations, is excellently shown in 

 such a thing as playing the piano by heart. Here the 

 actions duly follow in orderly series in connection with felt 

 touches of the keys and heard sound of the notes. Let a 

 key stick, or a wire become dumb, and the automatic 



