180 



Cincinnati Society of Natural History. 



presumed to be for the evolution of intelligence, or for carrying- on 

 mental efforts. The hypothesis has been ventured that men with deep 

 sulci (cerebral furrows), and thick masses of "grey" material in the 

 convolutions, are mentally the most competent. 



Gall and Spurzheim mapped the surface of the brain, and ascribed 

 certain functions to each segment of the exterior convolutions. Un- 

 der the name of phrenology these enterprising scientists engaged the 

 attention of the civilized world fifty years ago; but now their alleged 

 "system" has fallen into neglect and disrepute. Flourens was the 

 first to successfully assail the doctrine of the phrenologists. He 

 showed by experiments on the lower animals that the functions of the 

 cerebellum had not been rightly conjectured ; that this great ganglion 

 of gray and white neurine was not devoted to physical love — amative- 

 ness — but to muscular co-ordination. By excising a lateral half of 

 the cerebellum, the animal — pigeon or guinea-pig — could no longer 

 stand upright, but in a struggle whirled around and around. The 

 removal of the entire cerebellar mass leaves the sufferer to fall in a 

 sprawling attitude and to continue helpless. 



Flourens called attention to the fact that only about one third of the 

 cerebral convolutions are presented to parts of the cranium that can 

 be manipulated; that all the double space between the hemispheres is 

 covered with convolutions, as well as all that great expanse resting on 

 the floor of the skull and the tentorium. He demonstrated, through 

 vivisections, that certain parts of the cerebrum are "motor" in func- 

 tion, and certain other parts are " sensory," and none conformed to the 

 fanciful notions of organologists. 



The symptoms observed in different parts of £he body, after lesion 

 of certain convolutions, have done much toward a rational localization 

 of the different regions of the cerebrum. 



The famous " crow-bar case," in which a tamping-iron was blown 

 through the frontal lobes of the cerebrum, shows that the anterior con- 

 volutions are neither motor nor sensory. The victim of the premature 

 explosion rode home after receiving the injury, and gave an intelligible 

 account of the accident. However, after recovery, except the loss of 

 sight in one eye, Mr. Gage was uncommonly irritable, and was regarded 

 as of unsound mind. 



Abscess of either of the three tiers of frontal convolutions, results in 

 coma, or disturbed intellect. If a part of the cerebrum, in the fissure 

 of Sylvius, near the isle of Reil, be injured, the patient suffers from 

 aphasia; and parts adjacent to the fissure of Rolando seem to be de- 

 voted to motility of the arm, leg and corner of the mouth. A spot on 



