NERVOUS SYSTEM. 83 



Q. What relation does the size of the brain bear to the 

 nerves, in man and quadrupeds? 



/#. It is in an inverse proportion. In man, the brain is 

 very large in proportion to his nerves; in quadrupeds, ge- 

 nerally, the brain is small and the nerves large. 



Q. What is the result of this? 



/#. That although brutes are superior in some of the 

 senses to man, man in the sense of touch surpasses animals 

 greatly. Touch implies intellect beyond instinct; hence 

 the perfection of the organs of touch and the development 

 of the brain, are, in man, in proportion to each other. 



External forms of the, Nervous System of Animal Life. 



Q. From what part of the brain do the cerebral nerves 

 originate? 



A. From the cerebrum, tuber annulare and its conti- 

 nuations, and from the medulla spinalis. 



Q. To what opinion did this origin of these cerebral 

 nerves give rise? 



t#. As none originated from the cerebellum, the cere- 

 brum was said to be the source of the voluntary, and the 

 cerebellum that of the involuntary motions. 



Q. To what nerves does the cerebrum give rise? 



Jl. To the olfactory and the optic. 



Q. For what are these nerves remarkable? 



t/?. Their adhesion is firm at their origin from the brain, 

 and they are much softer than most of the other nerves. 



Q. What nerves arise from the tuber annulare and its 

 elongations? 



#. The motores communes of the muscles of the eye, 

 the pathetici, the trigemini, the motores externi of the eye, 



