Geology and Natural History. 243 
forms of expression common to man and the lower animals. The 
common tendency, when any strong exertion is made with the 
upon, but it is difficult to say what the ideas » no 
doubt, a close relation between certain muscular movements and 
certain ideas which prove capable of explanation. This 
convolution, and it is generally associated with paralysis of the 
night hand, and the reason might be supposed to be that the part 
of the brain affected is nearly related to the part governing the 
movements of the right hand. 
It is essential to remember that the movements of the mouth are 
P 
governed bi-laterally from each hemisphere r. 1s Sym- 
metrical, and I hold it to be a mistake to suppose that the faculty 
Speech is localized on the left side of the brain. e reason 
Why an individual loses his speech when the left side of the brain 
18 diseased is simply this. Most persons are right-handed, and 
therefore left-brained, the left. side of the brain governing the right 
side of the body. Men naturally seize a thing with the right hand; 
they naturally therefore use rather the left side of the brain than 
the right, and when there is disease, there the individual feels like 
one who has suddenly lost the use of his right arm. _ 
_L may, finally, briefly allude to the results of stimulating the 
i ganglia. Stimulation of the corpora striata causes the 
Imbs to i. 
eo. Harley alluded to the 
functions, and the possibility 
Ref logy 2 
tion in the interior of the brain, and quite another to specify func- 
