I 



390 MUSCULAR ACTION 



of muscle-fibers to one nerve-fiber in the eye-muscles compared with their 

 number in the gluteus maximus or other strong, gross muscle; it is many 

 times greater in the former case. In other words, each muscle-cell is 

 controlled in more detail in a skilled muscle than one which is unskilled. 

 The power of coordination with its neighbors is by this means greatly 

 enhanced, and the resulting bodily movements are within limits of 

 accuracy not before realized. 



When this skill in adjusting movements has been acquired by many 

 functional groups of muscles in different parts of the body, the nervous 

 system developing in ever-increasing ratio, we call the individual clever, 

 meaning thereby that he can do many things well. 



A person becomes clever as an individual, as a "mind," usually only 

 through having done many sorts of things with his neuro-muscular 

 mechanism. This is a firm basis for the philosophy of utilitarianism y 

 and a reason for a large increase in the "manual' 7 training and the 

 "physical" education of men and women. Except to the narrowest 

 individualism, knowing (however clear and deep the insight) without 

 some sort of doing is almost a reproach. 



In the actual psychophysical personality, then, we cannot separate 

 that which is the immediate outcome of muscular activity from that 

 known to the older psychology as "mental." These two aspects develop 

 together, stand in the same grade of values, and both take important 

 part in men and women as we would always wish to know them. Per- 

 haps at a later day physiologists will be able to explain this fact, which 

 is more and more obvious to educators, by reference to association- 

 impulses running everywhere in the body, especially in the brain. 



Special Muscular Functions. The means, largely muscular and 

 neural, by which posture, locomotion, speech, and emotional reactions are 

 accomplished seem important enough to receive special description,, 

 however brief it must necessarily be in comparison with the complexity 

 of these processes themselves. Speech especially is an intricate sub- 

 ject of importance which can receive here by no means adequate dis- 

 cussion, having to make room for things more immediately practical. 

 These brief descriptions will serve not only to explain these particular 

 neuro-muscular processes, but also as examples of the numberless 

 highly elaborate coordinated movements, etc., which the vegetative and 

 voluntary muscles and the nervous system achieve. 



Posture. We have several times mentioned muscular tone, and it is 

 in discussing posture that we see one of its functions so far as the skeletal 

 muscles are concerned. These latter are not wholly organs for producing 

 active movement, but have another important use in maintaining the 

 body and its parts in the numberless positions into which previously 

 they have placed the body. During life this muscular tonus plays a 

 very important part in our control of our organisms. It is characteristic 

 of life and is maintained even in the deepest sleep. It departs, however,, 

 at death unless the conditions are such that it is promptly merged into 

 rigor mortis. If one compare the posture of a sleeping body lying flat 



