EXTIRPATION OF THE CEREBRUM. 331 



The observations of Flourens have been repeated by nu- 

 merous experimentalists, and were, in the main, confirmed, 

 except as regards the special senses. Bouillaud, in 1826, 

 made a large number of observations on pigeons, fowls, rab- 

 bits, etc., in which, after removal of the hemispheres, he 

 noted the persistence of the senses of sight and hearing. 1 

 Longet finally demonstrated the fact that both sight and 

 hearing are retained after extirpation of the hemispheres, 

 even more clearly than Bouillaud, by the following experi- 

 ments: He removed the hemispheres from a pigeon, the 

 animal surviving the operation eighteen days. When this 

 animal was placed in a dark room and a light was suddenly 

 brought near the eyes, the iris contracted and the animal 

 winked ; " but it was remarkable, that when a lighted candle 

 was moved in a circle, and at a sufficient distance, so that 

 there should be no sensation of heat, the pigeon executed an 

 analogous movement with the head." An examination after 

 death showed that the removal of the cerebrum had been 

 complete. An animal deprived of the hemispheres also 

 opened the eyes at the report of a pistol, and gave other 

 evidence that the sense of hearing was retained. 2 



AVith regard to the senses of smell and taste, it is more 

 difficult to determine their presence than to ascertain that 

 the senses of sight and hearing are retained. It is probable, 

 however, that the sense of smell is not abolished, if the hemi- 

 spheres be carefully removed, leaving the olfactory ganglia 

 intact ; and there is no direct evidence that extirpation of 

 the cerebrum affects the sense of taste ; indeed, in young 

 cats and dogs, Longet has noted evidences of a disagreeable 

 impression following the introduction of a concentrated solu- 

 tion of colocynth into the mouth, as distinctly as in- the same 

 animals in a normal condition. 3 



1 BOUILLAUD, Recherches experimentales sur lesfonction* ducerveau. Journal 

 de physiologic, Paris, 1830, tome x., p. 36, et seq. 



2 LOSGET, Traite de physiologic, Paris, 1869, tome iii., pp. 328, 329. 

 8 Op. efc, p. 430. 



