380 BRANCH CHORDATA 



rounded case, while that of the apes is smaller and deeply ridged 

 and contains a smaller brain. Man's outstretched hand does 

 not reach the knee and the thumb is much more useful. The 

 hallux (great toe) is not opposable. There are no laryngeal 

 pouches. " The minute diverticula, the ventricles of Morgagni, 

 alone remain to testify of a former howling apparatus in the 

 ancestors of man." 1 



Man has the power of articulate speech and the faculty of 

 reason. As to whether this vast difference in reason be one 

 of kind or degree, psychologists disagree, but all concede that 

 the reasoning power of man is far in advance of that of any 

 other animal. 



Man's superiority over animals lies in his highly developed 

 powers of abstract thought, reason, and will. Through these 

 powers he is able to adapt himself to his environment, make a 

 new environment, or migrate to one better suited to his needs. 

 He can control the lower forms of animal life and modify them 

 by artificial selection and breeding to satisfy his wants. From 

 them he procures clothing, leather, food, ornaments, weapons, 

 fertilizer for his land, and materials used in his houses. He 

 uses them as beasts of burden or as means of travel. Through 

 undue use or slaughter he has caused the extinction of various 

 species. 



The student has missed the greatest value of the study of 

 zoology if he has not discovered that the great underlying 

 principles which permeate and control all animal life from the 

 lowest to the highest forms necessarily apply also to the life, 

 development, and history of mankind. Descent with adaptive 

 modifications is amply illustrated in the descendants of one 

 man during his lifetime. The influence of environment, 

 growth and decay, heredity, variation, adaptation, the survi- 

 val of those best adapted to conditions in the physical or the 

 business world, the strengthening of powers of body or mind 

 by use, the degeneration of powers by dependence upon others, 

 the sacrifice of the parent for the offspring everywhere seen in 

 nature, or the triumph of altruism over egoism in the service 

 of one's family or his fellow-men these are some of the bio- 

 logic principles directly applicable to man. 

 1 Beddard, p. 589. 



