MAMMALIA— PHYSIOLOGY 421 



histological development of the cerebral hemispheres in the higher 

 apes is about that of a microcephalic idiot. The behavior of the 

 apes shows many human traits in that capacity for learning and 

 intelligent acts can be interpreted. 



The work of Yerkes (" Almost Human ") and of Kohler has 

 shown the ability of the chimpanzee, and to a less extent the gorilla, 

 to recognize complex relations in problems set the animals and has 

 indicated a capacity to plan solutions and to utilize simple tools. 



Man has developed a remarkable reasoning power and has 

 brought with him a high development of conscience and a religion. 

 Even the most degraded savage worships something. The dis- 

 coveries of archaeologists show that wherever human remains are 

 found, tokens of idol or deity worship accompany them. 



Man is continually at warfare with other animals and with his 

 fellow men. As man's religion and sympathy become more strongly 

 developed we find that his attitude towards gaining possessions by 

 aggressive warfare decreases.^ 



It is necessary for the life of any organism that it be properly 

 adjusted to its environment. The more plastic the mind, the more 

 easily does life continue. The very process of education tends to 

 keep the mind open and to prolong the period of mental adolescence. 



Physiology of the Vertebrate Animal 



In the vertebrate type of animal we distinguish from a physio- 

 logical point of view the following principal organs: those of diges- 

 tiorty respiration^ circulation^ excretion^ reproduction^ muscular system, 

 which is the organ of movement, and the nervous system, the organ 

 of control. 



The body is made up of a bony framework, the skeleton, with 

 muscles and fat covered with skin. Food is taken into the mouth, 

 digested by the alimentary system, the wastes are carried off by the 

 excretory system, the lungs and the skin, and the sustaining portions 

 are carried around to the tissues by the ^/oo^ which brings the wastes 

 from the tissues to the excretory system. The lungs serve to aerate 

 and purify the blood before its return to the organs of the body. 

 The interdependence of the various systems calls for a governing and 

 correlating center, the nervous system. It is constantly functional in 



1 " The human animal cannot be aware of beauty except in self-forgetfulness, and 

 it cannot produce beauty except in self-forgetfulness." Arthur Clutton-Brock. 



