382 



BOVINE PATHOLOGY. 



close up the large cavity, but not sufficient to replace a 

 great part of the membranous walls. The brain is im- 

 perfectly developed. Sometimes we find only the floor of 

 the cranium present, its bony walls being entirely absent, 

 and the margins of the imperfect walls regularly 

 rounded off. 



Paeasites occasionally grow in the brain. These are 

 the same hydatids as are seen in the brain of sheep, giving 

 rise to "turnsick.''^ They are known as Gcenuri cerehrales, 

 are the larval form of the Taenia coenurus, seen in its and 

 adult state in the dog. They affect various parts of the 



Fig. 73. — Ccenurus cerehralis. 

 (After Cobbold). 



Fig, 74. — Ccenurus cerehralis. 

 (a) In situ, (After Cobbold). 



brain, generally the cerebral hemispheres. The embryo 

 which has escaped from the ovum of the tapeworm bores 

 its way through the tissues and enters a blood-vessel. It 

 lis carried in the round of the circulation to the brain, and 

 there locates itself. It increases in size, and generally is 

 large before it causes any appreciable symptoms, which 

 are those due to circumscribed deficiency of a portion of 

 the brain, or some forms of pressure on the surface, viz. 

 constantly moving round and round in the same direction, 

 and generally towards the side on which pressure is made. 

 The disease is most prevalent in young animals, and in 



