580 Causes and Course of Organic Evolution 



reduced in amount and fine in texture. When primitive man 

 took to dress, he thereby adopted a means of substitution and 

 ada])tabiHt3% that, combined with the frequent arboreal habit, 

 ensured gradual absorption of hair owing to withdrawal of the 

 stimuli that called it forth. 



Another and alternate cause, however, seems in part to have 

 operated. A few of the living species of monkey make nests 

 in trees, or shelters in caves. That the latter habit was not 

 unfreC(uently adopted by primitive man is demonstrated by 

 the cave-dwellings and their human remains already known to 

 us. This coupled with the clothing habit would equally tend 

 to hair absorption. 



If we again continue the study of dress, it can be said that 

 appreciation of color blendings and contrasts, individual rivalry, 

 sex selection, and other causes, would all conspire to the gradual 

 production of more and more striking woven fabrics or dyed 

 skins, such as many comparatively primitive nations still pre- 

 pare and appreciate. 



But the hand that first shaped a rude, even a huge, needle 

 gave a great stimulus for the future. For more and more 

 closely and delicately interwoven fabrics then engaged the eye, 

 the hand, the brain; w^hile it reciprocally stimulated currents 

 of afferent and efferent energy along all of these organs. Such 

 rough simple needles, that the hand and eye guided, may long 

 have held sway. But a primitive loom, like that of some savage 

 races now living, became a constantly moving needle with 

 abundant reserve of thread that the hand, the eye, and even 

 the foot guided in its active course. The climax came w^hen 

 the hand of man, working in rhythmic energizing activity 

 with his increasingly complicated brain, fashioned steam engines 

 and greatly more intricate machines, that enabled a pair of 

 hands and an alert brain ta accomplish in a day what once 

 recpiired a month or even a year to achieve. 



The history of the shoe as an article of protective and de- 

 fensive clothing equally demonstrates that hand, eye, and brain 

 act and react on each other. But it should here be emphasized 

 that the eye acts largely, almost wholly, as a sensitive con- 



