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 esthetic 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, 
