Functions of the Cerebellum. 623 



muscles, leaving certain others free to effect a twisting of the spinal 

 column, the balancing influence of the cerebellum being suspended. 

 The injury to the cerebellum is not usually accompanied by a loss of 

 sensibility. A bird deprived of its cerebellum can perform any single 

 reflex muscular movement, such as to kick with its legs, or flutter its 

 wings, but it cannot stand, balance itself, or walk, since these acts are 

 compound, and require a combination of muscular movements. It does 

 not lose the sense of sight, or other senses, or become stupid or affected 

 with convulsions; effects which follow the loss or injury of the cerebrum. 

 Inflammation of the membranes covering the cerebellum does not pro- 

 duce delirium, and it may be nearly destroyed by softening without en- 

 tailing a loss of intellect. But almost all sorts of injuries to the cere- 

 bellum entail a loss of muscular control, unsteadiness of gait, or eccen- 

 tric muscular movements, none of which effects follow lesions of the 

 cerebrum. 



A girl died of phthisis, at Lancaster, Eng., in 1884> at the age of 15, 

 whose brain was found to be in the following condition : whole weight 

 42 oz. , cerebrum well developed, corpora quadrigemina of normal size 

 and appearance, cerebral peduncles all right. But the olivary bodies 

 of the medulla oblongata, the pons varolii and the left lobe and vermi- 

 form process of the cerebellum, were nearly obliterated, while the right 

 lobe, which constituted its main portion, was only a half square inch in 

 size, and a quarter of an inch thick at the base. This lobe, however, 

 had the normal laminated appearance and structure. This person had 

 been somewhat weak in intellect, but was not deficient in l ' her sensory 

 faculties, general or special, and the only peculiarity observable in her 

 motor powers was a general muscular weakness, and tremor of the hands 

 when she was using them ( but this was attributed to the debility asso- 

 ciated with her phthisical condition ). But she could walk well and 

 steadily, though she was never known to run. " ( Ferrier.) 



A girl named Alexandrine Labrosse ( reported by Combrette ) < ' lived 

 to the age of eleven years, and it was found after death that the cere- 

 bellum was entirely atrophied, its place being occupied by a cyst con- 

 taining serum. Physical^, she was well developed for her age, but she 

 was five years of age before she was able to stand, and at the age of 

 seven she was very insecure on her legs, and often fell. Her intelli- 

 gence was defective, and her articulation indistinct, but all her sensory 

 faculties were normal. " 



In cases of congenital deficiency of the cerebellum, like the above, 

 the centers of muscular movement in the cerebrum, which, as we shall 

 see, exist independently in that organ, become the chief substitute for 

 the cerebellum. Such power of muscular combination as was shown in 

 the foregoing cases, was due to a superior education of the cerebral cen- 



