170 MAN, — THE ANIMAL 



these different connections and it is in this highly, 

 technical field that we may expect future revela- 

 tions. 



All attempts to discover what happens to a 

 stimulus after it enters the brain have thus far 

 been a complete failure. How a heat stimulus 

 can be translated into a specific command to the 

 muscles to contract in a definite manner is un- 

 known. This leaves the relationship of nerve 

 activity to mind, to memory, to instincts and to re- 

 flex action yet to be discovered. While the exact 

 connection between a sensory stimulus and a 

 muscular reaction is not fully understood, it is not 

 to be concluded that no progress has been made. 

 There are a host of facts that justify Parker in 

 making the following generalizations: "Not only 

 are our sensations thus activities of the cortical 

 part of the brain, but there is good reason for be- 

 lieving that our whole conscious life is similarly 

 restricted. In the cerebral cortex lies memory 

 with Its wealth of stored experiences, in this organ 

 love, hate and fear come into being; here arise the 

 cool deliberations of the man of science, the 

 dreams and aspirations of the poet, the passion of 

 the religious enthusiast, and, when abnormalities 

 intervene, the ravings of the mad man. Con- 

 trary to ancient belief, the spleen does not en- 

 gender temper, nor do the affections flow from 



