372 MAN --AN ADAPTIVE MECHANISM 



thyroid ; as the relief secured for an overworked man 

 by rest, or for the harassed individual by substituting 

 hope for fear. All these are mechanistic phenomena 

 in the life career of man as an individual. 



We have pointed out incompletely and imperfectly 

 the mechanistic role played by the organs and tissues 

 of the body in transforming the energy needed for the 

 daily routine of life, and in maintaining the chemical 

 purity of the body, especially when excessive metabol- 

 ism results from intense emotion, infection or muscular 

 exertion. Let us now briefly consider how the indi- 

 vidual, like other mechanisms, is modified by the im- 

 pairment or the deprivation of certain parts. 



Excision of Organs 



Brain: When the brain is progressively destroyed 

 by cerebral softening, the conversion of energy in 

 muscular action and fever is correspondingly dimin- 

 ished. When a certain percentage of brain-cells has 

 been lost, then the brain can no longer adequately 

 drive the body and a state of equilibrium is reached - 

 the individual is dead. If the cerebral hemispheres 

 and the cerebellum are removed from an animal, it 

 may live for months or years, but it cannot respond to 

 stimuli affecting the distance or contact ceptors. That 

 is, it possesses no associative memory. A decerebrate 

 infant is short-lived. An individual with a defective 

 brain an idiot may live for many years, but his 

 activities are limited. The function of the brain may 

 be depressed or even temporarily suspended by mor- 

 phia, acidosis, fever, emotion, exertion or physical 



