1 76 COMPARATIVE PHYSIOLOGY OF THE BRAIN 



images je dirai qu'il existe dans le cerveau quatre im- 

 pulsions spontanees ou quatre forces qui seraient pla- 

 cees aux extremites de deux lignes, qui se couperaient 

 a angle droit, Tune pousserait en avant, la deuxieme en 

 arriere, la troisieme de droit a gauche en faisant rouler 

 le corps, la quatrieme de gauche a droite en faisant 

 executer un mouvement semblable de rotation. Dans 

 les diverses experiences d'ou je tire ces consequences 

 les animaux deviennent des especes d'automates mon- 

 tes pour executer tels ou tels mouvements et incap- 

 ables d'en produire aucun autre." The last statement 

 goes too far, but Magendie's main thought deserves 

 more consideration than it has heretofore received 

 from physiologists. The galvanotropic facts men- 

 tioned in Chapter XI. show most conclusively that in 

 Crustaceans and Vertebrates there exists a relation 

 between the orientation and function of certain motor 

 elements, and a similar relation also finds expression in 

 the experiments on the horizontal semicircular canal. 1 



1 Dr. Lyon has shown that only the stimulation of the horizontal canal gives 

 rise to motions in the plane of this canal, while the same result cannot be ob- 

 tained with any degree of certainty through a stimulation of the two other 

 canals (4). 



BIBLIOGRAPHY. 



1. FERRIER. The Functions of the Brain. New York, 1886. 



2. LUCIANI, LUIGI. Das Kleinhirn. Leipzig, 1893. 



3. FLOURENS, P. Fonctions du Systime nerveux. Paris, 1842. 



4. LYON, E. P. A Contribution to the Comparative Physiology 

 of Compensatory Motions. The American Journal of Physiology, 

 vol. iii., 1900. 



