354 CCENURUS CEREBRALIS IN CATTLE AND SHEEP. 



ccenurus cerebralis in the brain, have not been considered 

 those of sturdy. The variety of ways in which the sturdy 

 manifests itself, depends entirely on the number of, and the 

 position held by the parasites in the brain. Usually but one 

 hydatid is found within the skull, sometimes several, and then 

 the symptoms are complicated. 



The usual form of sturdy depends on the presence of a 

 hydatid in one of the hemispheres of the cerebrum, or brain 

 proper. The sheep then turns right or left, according to the 

 hemisphere affected. If the bladder be situated between the 

 hemispheres, the head is protruded and elevated, and the 

 animal moves in a straight line forwards. Lastly, if the 

 bladder be lodged in the lesser brain or cerebellum, there is 

 defective co-ordination of movement; the creature loses con- 

 trol over the voluntary muscles, there is a peculiar uncer- 

 tainty of gait; the limbs do not obey the will. 



In addition to the above symptoms, there are others which 

 have not been studied as much as they might have been, 

 though of great interest to the physiologist. Such signs are 

 peculiar to different stages of sturdy. We observe that when 

 first affected, the symptoms are very severe; there is much 

 cerebral disturbance from the congestion produced by the 

 presence of the hydatid. As the brain substance yields to the 

 latter and is absorbed in other words, as the contents of the 

 skull adapt themselves to the parasite, the symptoms may 

 subside more or less, and a sheep decidedly giddy, stupid, and 

 dull at first, may appear partially to recover; but the growth 

 of the parasite, or any cause favouring cerebral congestion, 

 induces a marked exacerbation of symptoms. But, as Dr 

 Davaine has correctly stated, the vertigo cannot be explained 

 as depending on simple morbid irritation, or looked upon as 

 a symptom of paralysis or incomplete hemiplegia. The at- 

 tacks of giddiness, the running round and round, become 



