Physical Evolution of Man 583 



It can appropriately be said, therefore, that, when man is 

 viewed from the standpoint of his physical frame, he is "the 

 hand animal." His increasingly erect posture was at first con- 

 tributory to hand action, and eventually determined by it; 

 his plantar progression gradually resulted as an equilibrating 

 adjustment, when he not only grasped objects, but carried 

 them to a distance with him by aid of one or both arms; his 

 readjustment of muscles, of bone-surfaces for attaclmient of 

 these, of nerves and other tissues of the body, were, we would 

 consider, mechanically effected to preserve the upright atti- 

 tude, and to act as contributory helps to efficient working of 

 the arms and hands. So the extremely slow but nevertheless 

 steady increase in size of the brain and in its weight has, 

 we consider, proceeded with, and been stimulated to growth 

 by, activity of hand and arm as collectors and transmitters of 

 environal stimuli to the brain. 



This acquisition it is, also, which has enabled him more and 

 more surely to become "the dominant animal." For in fash- 

 ioning, by hand and brain action, rude gins and snares, by 

 digging and skillfully covering pitfalls, by devising more and 

 more destructive weapons, by utilizing poisons that his hand 

 had concocted, by taming the horse and then organizing game 

 drives, by excavating or building canoes or ships, and follow- 

 ing prey into every recess of land and water, he has made other 

 animals accessory to him, or has exterminated such as he desired. 



And in recent decades the hand and brain have combined 

 reciprocally to recognize, separate, cultivate, and apply anti- 

 dotes, antitoxins, and antagonists, that lessen or destroy the 

 action of those organisms, the bacteria and "microzoa," that 

 once marched tlirough the ranks of humanity as mysterious 

 wholesale destroyers; or that spread as "blight," canker, or 

 mildew, to blast the plants that he looked to, in the wild or 

 in the cultivated state, for his supjjort. 



Even the international means now ado})ted bj^ telegraph, 

 cable, telejihone, and wireless telegraphy, to locate disease 

 areas, are a trimnph of hand-arm action, reciprocally working 

 with brain energy, toward a common end. 



