FUNCTIONS OF THE CEREBELLUM. 369 



human subject. The results of this mutilation are as defi- 

 nite, distinct, and invariable", as in any experiments on living 

 animals, and, taken by themselves, lead inevitably to but 

 one conclusion. 



AVhen the greatest part or the whole of the cerebellum is 

 removed from a bird or mammal, the animal being, before 

 the operation, in a perfectly normal condition, and no other 

 parts being injured, there are no phenomena constantly and 

 invariably observed except certain modifications of the volun- 

 tary movements. The intelligence, general and special sen- 

 sibility, the involuntary movements, and the simple faculty 

 of voluntary motion, remain. The movements are always 

 exceedingly irregular and incoordinate ; the animal cannot 

 maintain its equilibrium ; and, on account of the impossibil- 

 ity of making regular movements, it cannot feed. This want 

 of equilibrium and of the power of coordinating the muscles 

 of the general voluntary system causes the animal to assume 

 the most absurd and remarkable postures, which, to one ac- 

 customed to these experiments, are entirely characteristic. 

 Call this want of equilibration, of coordination, of " muscular 

 sense," an indication of vertigo, or what we will, the fact 

 remains, that regular and coordinate muscular action in 

 standing, walking, or flying, is impossible, although volun- 

 tary power remain. It is well known that many muscular 

 acts are more or less automatic, as in standing, and, to a cer- 

 tain extent, in walking. These acts, as well as nearly all 

 voluntary movements, require a certain coordination of the 

 muscles, and this, and this alone, is abolished by extirpation 

 of the cerebellum. It is true that destruction of the spiral 

 canals of the internal ear produces analogous disorders of 

 movement, 1 but this is the only mutilation, except division 



1 FLOUREXS, Recherches experimentales sur les proprietes et les functions du 

 tysteme nerveux, Paris, 1842, p. 446. 



GOLTZ, Ueber die physiologische Bedeutung der Bogengdnge des Ohrlabyrinths. 

 Archivfiir die gesamtnte Physiologic, Bonn, 1870, Bd. Hi., S. 172, et seq. 



Taking the results of his experiments as a basis, Goltz proposes the theory 

 that the semicircular canals are the organs presiding over the sense of equilib- 



