THE NERVOUS SYSTEM 



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column, and connected with one another and with the 

 central nervous system by nerve fibers (Sec. 304). 



290. The Brain. The brain fills the entire cavity of the 

 skull, and consists of a number of separate masses of nerve 

 matter abundantly supplied 



with blood vessels (Fig. 98). 



The brain is the organ of 

 the mind; in other words, 

 it is the seat of con- 

 sciousness, the intellect, 

 the memory, the will, the 

 affections, the emotions, 

 and sensation. 



The brain controls all 

 voluntary motions. 



291. The Weight of the 

 Brain. The average weight 

 of the human brain is about 

 fifty ounces, or about three 

 pounds. 1 A few cases have 



1 The brain of Oliver Cromwell 

 is said to have weighed eighty 

 ounces. Daniel Webster's brain 

 weighed fifty-three and a half 

 ounces, and Ruloff's a notorious 

 murderer, but in some respects a 

 very learned man fifty-nine 

 ounces. The brain of Cuvier, the 

 celebrated naturalist, weighed 

 sixty-four and a third ounces ; and 

 that of Dupuytren, a famous 

 French surgeon, sixty-two and a 



half ounces. The hats of ten gentlemen were tried upon the skull of Robert 

 Burns, and the only one of the ten that could cover it was the hat of Thomas 

 Carlyle. An idiot's brain is usually small, rarely exceeding thirty ounces. 



FIG. 134. Diagram illustrating the 

 General Arrangement of the Nerv- 

 ous System. (Posterior view.) 



