THE ANIMAL, MAN (ANTHROPOLOGY) 



545 



Although no other brain, oxcopt that of the great elephants and 

 the gigantic whales, is actually larger than the human brain, it is not 

 the gross size and weight of man's brain that determines its pre- 

 eminent dominance. Quality as well as quantity of brain must 

 enter in as an important factor, as the relative size between the 

 weight of brain and body shows. It will be seen from the accom- 

 panying table that the hummingbird has three times as much brain, 

 compared to its body weight, as man, yet no one would say that it is 

 as intelligent as man. It is obvious that there are brains and brains, 

 with reference to quality as well as quantity. 



TABLE OF RATIOS BETWEEN THE BRAIN AND 

 BODY WEIGHT 



Rat .... 



Marmoset 

 Hummingbird 



1 :28 

 1 : 22 

 1 : 12 



The cerebral cortex, an interwoven tissue of nerve cells overlying 

 the anterior part of the brain of the higher vertebrates, is of supreme 

 importance as the center of intellectual life. An expert estimate 



abdomen 

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Diagram of the human cerebrum, showing the general 

 distribution of sensory and motor centers. 



has been made that the human cortex, which, if spread out flat 

 instead of being wrinkled and folded, would occupy about a foot and 

 a half square, contains over 9,000,000,000 nerve cells. These cells 

 are so .small that altogether they weigh a little more than a dozen 



