WEIGHT OF BRAIN CEREBELLUM. 127 



in some species of animals, but none approaches man in the 

 size of the brain proper. If man holds the first rank in 

 creation, he owes his position to this admirable instrument 

 of the soul, to this mysterious medium between the external 

 world and the thinking being. 



The volume of the brain is considerable from the first 

 stages of existence, and larger in proportion in the new- 

 born infant than in the adult. It is independent of sex 

 and of the size of individuals. The weight of the brain in 

 the adult varies, according to Cruveilhier, from 35 oz. to 

 52 oz. 



The brain is symmetrical, but less constantly so than some 

 other portions of the nervous centre, and there is often a 

 notable disproportion between the two hemispheres without 

 there having been any indication whatever of it during life. 

 This want of symmetry was very marked in the brain of 

 Bichat, and this is a striking proof that such a conformation 

 does not necessarily have an unfavourable influence on the 

 intellectual faculties, as was thought by this illustrious 

 anatomist. 



The cerebellum or little brain lies in the inferior occipital 

 fossae, that is to say, in the posterior and inferior portion of 

 the cranium, and it is covered by the posterior lobes of the 

 cerebrum. It is an ellipsoid in form, flattened from the top 

 downward, with its large extremity behind, and its greater 

 diameter transverse. It is symmetrical, and is composed 

 of a middle lobe and two lateral lobes or hemispheres. 



On the upper surface of the cerebellum is a protuberance, 

 extending from the front backwards ; it is formed by the 

 middle lobe, and named from its peculiar appearance the 

 superior vermiform process. The lateral lobes form an in- 

 clined plane on either side. 



The lower surface fits into the occipital fossae, and forms 

 two rounded lobes separated by a furrow, which widens in- 

 front to receive the spinal bulb. About the middle of it is 

 seen the inferior vermiform process, the lower surface of the 

 middle lobe which unites the two hemispheres. 



The whole surface of the cerebellum is furrowed with 

 curved and projecting lines, which give it a wrinkled appear- 



