NYSTAGMUS. OSCIIvI^ATORY MOVEMENT OF 

 THE EYE. 



This consists in spasmodic involuntary oscillation of the eye- 

 ball in a horizontal, lateral, oblique or rotary direction. In 

 animals it*has been seen in connection with poisoning and brain 

 diseases. Johne has observed it in horses in cerebro-spinal 

 meningitis, Wenderhold in epilepsy, and Moller in chloroform 

 anaesthesia. Moller has further seen it in puppies with con- 

 genital microphthalmos, and Siedamgrotzky in swine which had 

 been poisoned by herring brine. 



Slight cases of functional disturbance may improve under good 

 hygiene, open air life and tonics, cases due to poisons may re- 

 cover spontaneously when such poisons have been eliminated, 

 but those which depend on structural disorder of the brain are 

 beyond remedy. 



454 



