FUNCTIONS ,OF THE CEREBELLUM. 363 



ji all of his experiments, that lesion or irritation of the cere- 

 bellum alone produced neither pain nor convulsions ; * and 

 the same results have followed the observations of Longet 3 

 and of all modern physiologists who have investigated this 

 question practically. We have ourselves frequently exposed 

 and mutilated the cerebellum in pigeons, and have never 

 observed any evidence of excitability or sensibility. From 

 these facts, we must conclude that the cerebellum is inex- 

 citable and insensible to direct stimulation, at least as far as 

 has been shown by direct observations. It is not impossi- 

 ble, however, that future experiments may reverse this gen- 

 erally-received opinion ; particularly in view of the recent ob- 

 servations of Fritsch and Hitzig, already cited, 3 which show 

 that certain parts of the cerebrum are excitable, and that the 

 excitability of the encephalic centres rapidly disappears in 

 living animals, as the result of pain and haemorrhage. We 

 should note, also, the experiments of Budge, who observed 

 movements in the testicles and vasa deferentia, in males, and 

 in the cornua of the uterus and the Fallopian tubes, in 

 females, following irritation of the cerebellum. 4 Hammond 

 noted movements of this kind in cats just killed, and also 

 movements of the intestines and of the muscles of the ab- 

 domen, thigh, and back. 5 



Functions of the Cerebellum. 



There are still the widest differences of opinion among 

 physiologists, w r ith regard to the functions of the cerebellum, 

 mainly for the reason that the experiments upon the lower 



1 FLOURENS, Recherches experimentales sur les proprietes et les functions du sys- 

 teme nerveux, Paris, 1842, p. 18. 



li LONGET, Anatomic et physiologie.du systeme nerveux, Paris, 1842, tome i., pp. 

 783, 734. 



3 See page 323. 



4 BUDGE, Lehrbuch der specietten Physiologic des Menschen^. Leipzig, 1862, S. 

 788. 



5 HAMMOND, Physiology and Patludogy of the Cerebellum. Quarterly Journal 

 of Psychological Medicine^ New York, 1869, vol. iii., p. 223. 



