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APPLIED PHYSIOLOGY 



546. Brains of animals. The medulla is much the same in 

 all animals from the frog up to man. This is because breathing and the 

 flow of blood are much the same in all. The cerebellum in a frog or 

 snake or fish is very small, for they need but a small regulating and 

 balancing part. A bird or a hen must make precise movements in 

 balancing itself in fly ing or roosting, and so it has a large cerebellum. 



Brain of an ox. 

 a outline of brain in the skull. b the brain removed from the skull. 



The optic tubercles of frogs and birds are well developed, for their eyes 

 are perfect. The cerebrum of frogs and snakes and fishes is very small. 

 Its hinder parts are the largest, for in them the impressions of sight, 

 hearing, and smell are located. Its fore parts are mere points, as would 

 be expected from the low intelligence of the animals. A bird has a 

 larger cerebrum, corresponding to a greater mind. An animal's cere- 

 brum is much larger and is somewhat folded to give room for more 

 nerve cells, but the frontal or thought region is small. An animal's 



