FUNCTIONS OF THE CEREBELLUM. 367 



" At the end of a certain time, the pigeon had regained 

 its equilibrium ; the fowl did not regain it at all : the latter 

 lived nevertheless for more than four months after the opera- 

 tion." ' 



These important observations we have repeatedly con- 

 firmed, and have in our possession the encephalon of a pigeon 

 which recovered completely after removal of about two-thirds 

 of the cerebellum, the animal first presenting marked defi- 

 ciency in coordinating power. 



Such are the phenomena observed in experiments upon 

 the cerebellum in birds, and they have been extended by 

 Flourens a and others 3 to certain mammals, as young cats, 

 dogs, moles, 'mice, etc. Our own experiments, which have 

 been very numerous during the last twelve years, are simply 

 repetitions of those of Flourens, and the results have been 

 the same without exception. 



The only difficulties in operating upon the cerebellum 

 arise from haemorrhage and the danger of injuring the 

 medulla oblongata. The skull is exposed by slitting up the 

 scalp, and the calvarium is removed in its posterior portion, 

 penetrating just above the upper insertion of the cervical 

 muscles. It is well to leave a strip of bone in the median 

 line, thereby avoiding haemorrhage from the great venous 

 sinus, though this is not essential. The cerebellum is thus 

 exposed, and may be removed in part or entirely, by a deli- 

 cate scalpel or forceps, when the characteristic phenomena 

 just described are observed. Animals operated upon in this 

 way feel the sense of hunger and attempt to eat, but when 

 the movements are very irregular, they are unable to take 

 food. We have frequently compared the phenomena pre- 

 sented after removal of the cerebellum with the movements 

 of a pigeon intoxicated by forcing down the oesophagus a 



1 FLOUREXS, op. cit., p. 102. 

 8 Op. cit., p. 138, et seq. 



8 YULPIAX, Lemons sur la physiologic generate et compared du systeme ner- 

 veux, Paris, 1866, p. 606. 

 124 



