THE PHYSIOLOGY OF EXERCISE. 327 



nervous system comes into consideration in most composite movements. 

 The sight, the sense of pressure, and the muscular sense, and finally 

 the mind, must be prepared to take in the position of the body at each 

 instant, so that the muscles may be in a proper state of adjustment ; 

 this is plainly shown in the exercises of fencing, playing billiards, 

 rope-dancing, vaulting on horses in motion, or leaping down a mountain- 

 slope. Thus not only the motor, but the sensor nervous system also, 

 and the mental functions, are capable of being exercised and need it ; 

 and the muscles again appear to acquire a deeper importance in gym- 

 nastics. What is said here of the coarser bodily movements applies 

 equally to all skilled work, of the highest as well as of the lowest 

 kind. Although a Liszt, or a Rubinstein, without an iron muscularity 

 of arm, can not be thought of, and although, likewise, the movements 

 of Joachim's bow during a symphony may correspond to many kilo- 

 grammemetres, still their power as virtuosos resides in their central 

 nerve-system. The readiness of the turner, the machinist, the watch- 

 maker ; of the glass- blower and glass-polisher ; the skill of the anat- 

 omist and surgeon ; writing and drawing ; womanly labors like sewing 

 and knitting, crocheting and lace-making ; finally, the hardly consid- 

 ered yet more or less artful performances of daily life, dressing and 

 undressing, the use of the sponge, comb and brush, knife and fork 

 what are they all at last but acquired concatenations of the actions of 

 ganglion cells which, after they have often run on in an appointed 

 course, now succeed each other in the same manner with qualified facil- 

 ity, catching into each other, pausing and resuming again, like the voices 

 in an artfully composed concert ? When Lessing asked whether Ra- 

 phael would have been any the less a great painter if he had been born 

 without hands, he perceived this truth. Is it necessary to add that 

 the same principle applies to all the movements as well as to those of 

 the hands ; that, for example, vocal culture rests upon no other one ? 

 Singers need not only flexible vocal cords, strong respiratory and 

 laryngeal muscles, ringing resonance of the air-passages all these 

 would in themselves alone be of no more use to them than a Stradi- 

 varius violin to a wood-cutter their talent has its root in the gray sub- 

 stance at the base of the fourth ventricle. Here also is concealed, but 

 awaiting a higher command, exercising its functions through the 

 hinder third of the left third convolution, the machinery of the speech 

 mechanism, as bulbar paralysis sadly teaches. 



It is very remarkable in all these processes that the more any com- 

 posite movement is practiced, the more unconscious is the act of the 

 nervous system directing it, until at last the latter can not be distin- 

 guished from spontaneous nervous mechanisms like the involuntary re- 

 flex and by-movements. Erasmus Darwin remarked that, when any 

 one learns to turn, each movement of the hands seems at first to be 

 directed by the will, but that at last the action of the hands becomes 

 so at one with the effect that the turner's will seems to reside in the 



