174 



COMPARATIVE ZOOLOGY. 



The medulla oblongata is not only the medium of com- 

 munication between the brain and the spinal cord, but it 



Fig. 142.— Brain of the C;it (Felis do- 

 rnestica): a, medulla oblongata; b, 

 cerebellum; c, cerebrum. 



Fig. 143. — Brain of the Orang-utan, 

 upper surface; one third natural 

 size. 



is itself a nervous centre : the brain above and the cord 

 below may be removed without death to the animal, but 

 the destruction of the medulla is fatal. Of the twelve 

 pairs of nerves issuing from the contents of the skull (en- 

 cephalon), ten come from the 

 medulla oblongata. Among 

 these are the nerves of hearing: 



Fig. 144.— Human Brain, side view: 1, 

 medulla oblongata ; 3, cerebellum ; 5, 

 frontal convolutions of cerebrum. 



Fig. 145. — Human Brain, upper view, 

 one third natural size: 1, anterior 

 lobes ; 2, posterior; 3, great median 

 fissure. 



and taste, and those that control the lungs and heart. Res- 

 piration ceases immediately when the medulla is injured. 



