. PHYSIOLOGY OP THE POSTERIOR PITUITARY. 503 



If all the data we have submitted are considered collect- 

 ively, it seems to us that the following conclusion is warranted: 

 Removal of the hemispheres in an animal does not arrest its power 

 to execute normal bodily movements under external stimulation, 

 because these movements are dependent upon functional structures 

 situated in the lower part of the brain and in the spinal cord and 

 which the posterior pituitary body governs. 



Of course, this appears to contradict at once a great mass 

 of experimental and clinical testimony, but the contradiction 

 is only apparent. Eemoval of the motor region in the rabbit 

 gives rise to no detectable differences in the movements; the 

 injured animal is similar to an intact one. In the dog, the 

 same procedure, says Professor Foster, causes "loss or diminu- 

 tion of voluntary movement in the corresponding part of the 

 body"; but this is only temporary, and the animal may re- 

 cover to such a degree that the temporarily paralyzed limb 

 cannot be told from the normal one. Careful examination of 

 the brain. after death shows that no regeneration of the lost part 

 had occurred. Even removal of the whole motor area causes 

 no appreciable difference between the movements of the two 

 sides of the body to a casual observer. In the monkey the 

 results have been unequal: "While in some instances recovery 

 of the movement has, in the monkey, as in the dog, after awhile 

 taken place, in other instances the 'paralysis' has appeared to 

 be permanent." . . . "The facts, however, within our 

 knowledge relating to the permanence of the effect are neither 

 numerous nor exact enough to justify at present a definite 

 conclusion," says Professor Foster. "On the other hand, the 

 positive cases, where recovery has taken place, are of more 

 value than the negative ones, since in the latter the recovery 

 may have been hindered by concomitant events of a nature 

 which we may call accidental." We might add that a single 

 case of recovery in the monkey, when the motor area has been 

 completely removed, demonstrates that, generally speaking, 

 the structures are functionally similar in all higher animals, 

 including man, judging from such instances as the crow-bar 

 case, or one reported by Brown-Sequard, 11 in which an entire 



"Brown-Sequard: SocigtS de Biologic, 1876. 



