PART VI. 



MENTAL AND'PHYSICAL EXERCISE. 



THE BRAIN. 



633. Preparatory to treating of the sensorial functions, 

 we gave a summary account of the nervous system, as it 

 exists in various animals, with a figure of the ganglion ; 

 reserving more particular descriptions of the brain and its 

 functions as they are found in the human species, for the 

 purpose of connecting them with observations on physical 

 and mental exercise. 



634. Size of the Braii\. Aristotle and Pliny both as- 

 sert that the brain of man is not only comparatively, but 

 absolutely, larger than that of any other animal. At the 

 present time, only two exceptions to this assertion are 

 known. The brain of the whale, and that of the elephant, 

 are larger in bulk than that of the human species. Com- 

 paratively, however, the human brain is much larger than 

 that of any other known animal. By analogy, there- 

 fore, we might infer that in man, the largest development 

 of this organ would, other circumstances being equal, in- 

 sure the most capacious intellect, and perhaps this may be 

 considered as generally true. Says Magendie, " the vol- 

 ume of the brain is generally in direct proportion to the 



What is said of the absolute size of the human brain ? What is said 

 of the comparative size of this organ in man ? 



