ANATOMY AND PHYSIOLOGY OP NERVOUS SYSTEM. 705 



The vegetative functions (once that care is taken to nourish the 

 birds and clean them) are performed without disturbances. If the 

 bird lives for some time it shows a general deposit of fat. The skin 

 and muscles in particular are seen to be infiltrated with adipose 

 tissue. 



In these birds there are only movements of a reflex nature. 

 Sensibility is blunted since the stimuli are not able to reach the 

 cortical centers. Hence, they cannot provoke volitional acts in them. 

 S Ku'ss says, these birds live, but do not perceive; they hear, but 

 not listen; they are aware of stimuli upon the tongue, but do not 

 iste them. They are just as a human being who is asleep or absorbed 

 contemplation. He may drive a fly from the face without being 

 HI scions of it. 



Fig. 284. Effects of Ablation of Cerebrum. (DALTON.) 



When but one cerebral hemisphere is removed without in the 

 ist injuring the other and the animal recovers, it does not show 

 sitive disturbances of intelligence or of conscious sensibility or of 

 )luntary motion. However, the opposite side shows weakness, 

 lould the lesion extend to the underlying basal ganglia or to the 

 luncular system, there will be complete hemiplegia in the opposite 

 ide of the body. 



The same manifestations are observed in a man who has lost an 

 ttire hemisphere from a wound or from disease. There is no posi- 

 ive lesion of intelligence, but there is manifested very marked fatigue 

 )m intellectual labors. If the lesion has extended toward the 

 jduncular base of the hemisphere, there is hemiplegia in the oppo- 

 ite side of the body. 



The crowbar case is a much-cited instance. A workman twenty- 

 ive years of age was engaged in charging a blast in a rock. The 

 istrument he used was a sharp-pointed bar, forty inches long, one and 

 le-quarter inches in diameter and weighing twelve pounds. The 



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