NYSTAGMUS. OSCILLATORY MOVEMENT OF 

 THE EYE. 



Thi.s 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 ob.served it in horses in cerebro-spinal 

 meningitis, Wenderhold in epileps3^ and Moller in chloroform 

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

 genital microphthalmos, and Siedamgrotzk}- 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 remed}^ 



452 



