CEREBELLUM. 433 



and no attempt having been made at regeneration of the lost parts. 

 The accompanying figures, 143 to 146, show the appearances, in 

 this case, as compared with the brain of a healthy pigeon. 



We have also met with three other cases, similar to the above, in 

 which about one-half of the cerebellum was removed by operation. 

 The loss of co-ordinating power, immediately after the operation, 

 though less complete than in the instance above mentioned, was 

 perfectly well marked in character ; and in little more tha'n a fort- 

 Fig. 143. F,v. 144 



BRAIN- OF HEALTHY PIOEO x Profile BRAIK OP OPERATED PIGEON 



v.ew. 1 Hemisphere. 2 Optic tubercle. 3. Profile view showiajf the mutilation 



Cerebellum. 4. Optic nerve. 5. Medulla ob- of cerebellum. 



longata. 



Fig. 145. Fie. 14*3. 



BRAIN OF HEALTHY PIGEOX Poste- BRAIN OF OPERATED PIGEON 



rior view. Posterior view showing tLe mutila- 



tion of cerebellum. 



night the animals had nearly or quite recovered the natural control 

 of their motions. 



These instances show, accordingly, that a large portion of the 

 cerebellum may be wanting without a corresponding deficiency of 

 the co-ordinating power. If the theory of Flourens be correct, 

 therefore, these cases can only be explained by supposing that 

 those parts of the cerebellum which remain gradually become en- 

 abled to supply the place of those which are removed. It is more 

 probable, however, that the loss of co-ordinating power, which is 

 immediately produced by taking away a considerable portion of 

 this nervous centre, is to be regarded rather as the effect of the 

 sudden injury to the cerebellum as a whole, than as due to the mere 

 removal of a portion of its mass. 

 28 



