CEREBRAL HEMISPHERES AND MEMORY 239 



cerebral hemispheres on birds (4). The work of this 

 investigator, Goltz's article on the clog- without cere- 

 bral hemispheres, and Goltz's and Ewald's article on 

 the dog with shortened spinal cord are among the 

 best on the physiology of the central nervous system. 

 Until their work appeared, it was a dogma (and is 

 still in many text-books) that animals which have lost 

 the cerebral hemispheres can no longer move spon- 

 taneously. Flourens is responsible for the statement. 

 Schrader first disproved it in regard to the frog and 

 then succeeded in disproving it in the case of birds. 

 " None of the animals under observation [pigeons] 

 showed a sleep-like condition longer than three to 

 four days [after excision of the cerebral hemispheres]. 

 According to Rolando and Flourens, animals which 

 have undergone this operation, except when certain 

 stimuli are applied to the skin, remain absolutely 

 quiet. At first, this is true. The pigeons remain 

 standing, where they are placed, with ruffled feathers, 

 the head drawn in, the eyes closed, and often on one 

 leg. Occasionally they shake themselves, clean their 

 feathers with their beak, stretch sleepily, and in the 

 act of defalcation take a few steps. If left undis- 

 turbed, nothing else is to be observed. When thrown 

 up into the air, they fly down diagonally, strike ob- 

 stacles, and fall rather than alight on the floor, where 

 they at once sink back into their stupor again. If 

 the skin is stimulated, they take a few steps, but in so 

 doing are liable to run into obstacles" (Schrader, 

 loc. cit.). 



