DISEASES OF THE OX AND SHEEP. 471 



of Cestoda, are as follows : — The Cysticercus bovis is a mono- 

 cephalous bladder - worm found in the muscles, aponeurotic 

 tissues, and some of the viscera of the ox. The head is square, 

 and it is provided with four large suckers, and an additional 

 depression in the centre. This cysticercus diflfers from that of 

 the pig, the pork measle, in that the head is not armed, and 

 that the suckers are larger. The length is about J in. to J in., 

 and in exceptional cases 1 in. A half-pound of psoas muscle in 

 one case was found to contain 150 cysticerci. The Cysticercus 

 bovis is the larval form of the Tmnia viediocanellata of man. 

 These measles undergo calcareous degeneration very quickly, and 

 are destroyed in about six months. The Cysticercus ovis, or 

 mutton-measle, has been found in mutton on five occasions, and 

 the rather small tapeworm of man, which may be derived from 

 eating mutton, is called the Tcenia ienella. The Cysticercus 

 cellulosce, or pork measle, gives rise to the Tcenia solium 

 of man. 



The Cysticercus tenuicollis, or slender-necked hydatid, varies 

 in size, and may be as large as a cricket-ball. The head is pro- 

 vided with four suckers. This hydatid is the larval form of the 

 Tcenia marginata of the dog, and it infests especially sheep, 

 cattle, deer, and swine. The Cysticercus fistularis of the hog is 

 a long bladder-worm, and supposed to be merely a variety of this 

 Cysticercus tenuicollis of the sheep. The Echinococcus veteri- 

 norum is the larval form of the Tcenia echinococcus of the dog. 

 It may infest the vital organs of sheep, swine, cattle, horses, and 

 even man. When present in the brain of sheep_, it does not cause 

 symptoms as severe as those of sturdy, and probably the reason of 

 this is that the heads of the echinococcus do not protrude from the 

 cyst, whereas those of the Coenurus C6'r6'^r«//.v do protrude. The 

 two hydatids are alike in the fact that the eggs of each come 

 from a particular kind of tapeworm, which infests the intestines 

 of the dog, the Tcenia coenurus, and the Tcenia echinococcus 

 respectively. Larval cestodes have apparently not been found in 

 the elephant. 



Grid or sturdy in sheep is due to the presence of a cyst called 

 the Coenurus cerebralis in the brain. It is a very instructive 

 sight to see this cyst, and our readers may observe it for them- 

 selves in many museums. This disease is commonly met with 

 in all parts of the United Kingdom among sheep. In some 



