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HUMAN PHYSIOLOGY 



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principle here represented is that of the massing 

 together and extreme growth of certain brain 

 regions; that which distinguishes man being the 

 higher degree of growth and development repre- 

 sented, not merely in the fore brain itself, but 

 throughout the other parts included in the 

 constitution of the organ of mind. 



THE BUILD OF THE BRAIN. It is perhaps more 

 legitimate to speak of " brains " than to use the word 

 in the singular, seeing that the brain is not one 



organ, but a complex array 

 of different centres. Thus, 

 in one part of the brain we 

 may find many different 

 centres to be included, as 

 is the case with the great 

 mass of the brain (or 

 cerebrum) in man, which 

 represents the principal 

 and most important part 

 of the organ. The brain 

 regarded in a side view as 

 it lies in the head (Fig. 33) 

 would appear to consist of 

 two large masses only. Of these, one is much larger 

 than the other, filling the greater part of the cavity 

 of the skull. This is the cerebrum, or part to which 

 we have hitherto applied the name fore-brain (Fig. 

 33). The second prominent portion of the brain lies 

 below and behind the cerebrum, and is known as 

 the cerebellum, or lesser brain (Figs. 31 and 33). An 

 anatomical examination of the brain reveals other 

 centres lying deeply imbedded in the base of the 

 brain, and to these parts the general name of central 

 ganglia has been applied. Regarded externally the 



clmi 



Fig. 33 BRAIN IN POSITION 



(cb) Cerebrum. 

 (com) Cerebellum. 



