592 Causes and Course of Organic Evolution 



have inclined to view primitive man as a solitary or family 

 species only. But, except for the gorilla and a few lower types, 

 the apes and monkeys evidently enjoy optimum existence 

 when forming part of a communal life. Every zoological gar- 

 den is witness to this. 



Given such a communal life, when a few primitive men 

 paddled a log or dug out canoe to a fishing station, the paddling 

 at one time, the spearing of fish at another, the baiting of a rude 

 bone hook, the throwing of the line that held it, the watching 

 by eye and delicate feeling by hand for a nibble, the rapid in- 

 pulling of the captured prey, and the securing of it in triumph 

 meant constantly changing and transferred stimuli between 

 hand and brain. All such acts, as every civilized and even 

 more uncivilized group show, tend to changing conditions of 

 mental stimulation and excitement, along with ejaculations 

 suited to the moment. But no parts of the body except the 

 hand-arm, in conjunction with the eye, give rise to such diverse 

 stimuli. 



Even in the milder and more systematized efforts attendant 

 on hut-building, land culture, garment fashioning, and other 

 employments, communal or at least family aid and cooperation 

 seem nearly always to have prevailed. Thus at the present 

 day scarcely one rude tribe exists in which hand labor and 

 simultaneous active talk do not go hand in hand, for a con- 

 siderable period of each day. Advancing adaptation of the 

 hand to an ever widening range of pursuits stimulated the 

 brain to increased flows of energy, and so to increased complex- 

 ity and growth. Simultaneously also it stimulated to an ex- 

 pression of views on these pursuits, that even yet in "isolating" 

 languages are general, simple, and primitive, but which in 

 "agglutinative" ones are advancing to greater and greater com- 

 plexity and analytic exactness, as skill of hand and advancing 

 social organization conduce to more complex conditions of life. 



In all such advance by environal stimulation-action and 

 brain reaction, followed by proenvironal outreaching and suc- 

 ceeding response, the great law of proenvironment is con- 

 stantly at work. Thus given that two primitive tribes had 



