EXTIRPATION OF THE CEREBRUM. 335 



after a first impression. On the ground, a frog without the 

 brain when irritated makes, in general, two or three jumps 

 at the most ; it is rare that it makes but one. Placed in 

 water, it continues the movement of natation until it meets 

 with an obstacle ; it is the same in the carp, eel, etc. The 

 pigeon continues to fly, the duck and goose continue to 

 swim, etc. We should say that there is a spring which 

 needs for its action a first impulsion, and which is stopped 

 by the slightest resistance. But, what is striking, is pre- 

 cisely that continuation of the condition once determined, 

 and we cannot refrain from connecting the facts observed in 

 an animal deprived of the cerebral lobes with those which 

 constitute the characteristic properties of inorganic matter. 

 Brought into movement, the animal without a brain retains 

 the movement until there is exhaustion of the conditions of 

 movement, or until it meets with resistance ; taken in re- 

 pose, it remains in the state of inertia until an exterior 

 cause intervenes to bring it out of this condition. It is 

 living, inert matter." l 



There is now no room for discussion with regard to the 

 persistence of general sensibility after removal of the hemi- 

 spheres. The experiment upon a pigeon leaves no doubt 

 upon this point ; but the susceptibility to pain has been 

 much more strikingly illustrated in other animals. Yulpian, 

 in describing the condition of animals operated upon in this 

 way, illustrates the persistence of sensibility in rats and rab- 

 bits, by the violent cries which follow painful impressions. 2 



In concluding our consideration of the observations upon 

 inferior animals, it only remains for us to discuss briefly cer- 

 tain late experiments, which have attracted a great deal of 

 attention, from the fact that they seem to show that sponta- 

 neous volition exists after complete extirpation of the cere- 

 brum. These experiments have been most ably and satis- 



1 OXIMUS, Reclierches experimentaJ.es sur les phenomenes consecutifs d Tablation 

 du cerveau. Journal de t anatomic, Paris, 1870-"7l, tome vii., p. 644. 



2 VULPIAN, Systeme nerveux, Paris, 1866, p. 667. 



122 



