314 SECRETS OF ANIMAL LIFE 



But how is it done? How does the oil of joy, as 

 the Scriptures call it, operate in making the limbs 

 more supple and the face to shine? 



It is an indubitable fact that a joy say of 

 maternity, or discovery, or artistic creation may 

 become an exhilaration and enthusiasm of thought 

 and will; but the present problem is rather of the 

 bodily welfare. It is generally believed that emo- 

 tion has its physical accompaniment in strains and 

 movements throughout the body and in changes 

 in the secretion of glands; and it is certain that 

 this reverberation of joy is for good, since joy is 

 an index of the organism's well-being. It is also 

 well-known that the aesthetic emotion delight in the 

 beautiful is very markedly a body-and-mind 

 reaction, affecting the whole creature as a unity; 

 but the problem is whether joy does in any specific 

 physiological way enhance the efficiency of the 

 nervous system. Regarding the optic thalamus 

 of the brain as a great depot of sensory influences 

 and as a center of emotional reaction, Dr. Dear- 

 born suggests that influences from this region may 

 surge up into the cerebral cortex, the seat of the 

 higher mental processes, where joy and activity 

 are correlated. He speaks tentatively of "a 

 strong afferent or ascending flood of neural influence 

 through the optic thalamus (emotional ' center') 

 into the cortical mid-layers"; but whether this 

 means much or little, he has no manner of doubt 

 that joy has a direct influence on the integrative 

 function of the nervous system, 



