Parasites. 53 



eat or drink and wastes daily. But, if well-fed and ex- 

 citement avoided, it may even gain flesh. If tlie cyst is 

 situated on one side of the brain, the lamb ttu-ns 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 paralyzed. 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 para- 

 sites at any given moment. When the cyst is directly in 

 the median Hne, the sheep elevates its nose and advances 

 in a straight line until stopped by some obstruction. 

 "When located in +he back part of the brain, (cerebellum), 



Fig. 1. 



Fig. I — Coenurus Cerebralis. Sliowing the sac with its many heads (re- 

 duced). Also a single head magnified. 



the host Hfts its limbs in a jerking, uncertain manner, sets 

 them down in a hesitating way, stumbles 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 im- 

 provement, the remissions and aggravations being proba- 

 bly due to the varying activity of the parasite at different 

 periods. Simple tumors, maintaining a steadily increasing 

 pressure rarely give rise to such intermittent symptoms. 

 The ccenurus mostly affects sheep under two years old 

 5* 



