152 MAN, — THE ANIMAL 



dulla and the control of the muscles of the face, 

 neck, respiration and the heart arise from it. 

 (Fig. 52.) 



As soon as one examines the brain of a mam- 

 mal, dog, sheep, or man, the parts of the brain so 

 evident in the lower vertebrates are nearly all 

 hidden by the cerebrum. Technical studies in the 



Figure 51. Diagram of the human brain showing the same 

 areas as in Figure 50. The "nose brain" area is greatly re- 

 duced and drawn out into a minute strand that escaped notice 

 for many years. The "eye" and "ear" areas are proportionately 

 nearly as large. The enormous growth of the cerebral hemis- 

 phere overshadows these more primitive structures which con- 

 tinue to be the only avenue over which information of the phys- 

 ical universe reaches this highly specialized region. 



phylogeny of the cerebrum trace its origin back 

 into the simple animals such as turtle and frog, but 

 it does not play an important part in their nervous 

 activity. The cerebrum is the highest develop- 

 ment that any part of the brain reaches and the 

 climax of its growth is found in man. As soon 

 as the cerebrum became well organized it took 

 over the final control of important bodily re- 



