PARASITES. 



53 



unsteady gait, but with a tendency to move restlessly in one 

 direction. Left to itself, it neglects to eat or drink, and wastes 

 daily. But, if well-fed and excitement avoided, it may even 

 gain flesh. If the cyst is situated on one side of the brain, the 

 lamb turns to that side, moving in a circle and making a beaten 

 track. The limbs on the opposite side of the body act in a 

 disorderly manner, being partially paralysed. If there is one 

 on each side of the brain, the sheep will turn to one side or the 

 other, according to the relative activity of the parasites at any 

 given moment. When the cyst is directly in the median line, 

 the sheep elevates its nose and advances in a straight line until 

 stopped by some obstruction. When located in the back part 

 of the brain (cerebellum), the host lifts its limbs in a jerking. 



Fig. I. — CcEnurus Cerebralis. Showing the sac with its many heads (reduced). 

 Also a single head magnified. 



uncertain manner, sets them down in a hesitating way, stumblts 

 perpetually, falls and struggles for some time ineffectually in its 

 efforts to rise. If situated in the spinal cord, difficult breathing 

 and paralysis are marked symptoms. The disorders are often 

 extreme at first, and afterwards undergo a temporary improve- 

 ment, the remissions and aggravations being probably due to 

 the varying activity of the parasite at different periods. Simple 

 tumours, maintaining a steadily increasing pressure, rarely give 

 rise to such intermittent symptoms. 



The ccenurus mostly affects sheep under two years old. and 



