OUR DOMESTICATED ANIMALS. 59 



liver. Not only does this parasite infest ruminants, but 

 it likewise invades the viscera of other kinds of 

 mammalia, including monkeys, and even man himself. 

 In its adult condition it forms one of the numerous tape- 

 worms resident in the dog (Tcenia marginata) . This is 

 the bladder worm which Dr. Mollar swallowed in the 

 fresh state, hoping thereby to rear within his own 

 intestinal canal the adult representative worm in its 

 cestoid condition. The result was negative ; and it farther 

 appears that the dog, and the dog only, constitutes the 

 proper ultimate bearer of this large larval tapeworm. In 

 this reckoning, however (and in accordance with the 

 generally accepted view that dogs have descended from 

 wolves), we have to include the dingo, every other variety 

 of wild dog, and also the wolf. 



The Many -headed Hydatid. — As a fertile cause of 

 " gid," or sturdy, in sheep, this common helminth has 

 acquired notoriety, and it is well known to parasitologists 

 under the title of Goenurus cerebralis. When treating 

 of the ovine entozoa I shall necessarily dwell at some 

 length upon the general structure and development, and 

 also upon the ravages committed and the symptoms set 

 up by this bladder worm when lodged in the brain of the 

 sheep ; but in the meanwhile it is proper to notice that 

 the coenurus not unfrequently gives rise to sturdy in 

 cattle. 



Up to comparatively recent times, the records of 

 sturdy, or turnside, amongst English cattle have been — 

 to use an expression employed by the late Mr. Youatt — 

 " disgracefully scanty." We mean by this to say that, 

 considering the abundant proofs which veterinary practi- 

 tioners could supply respecting the occurrence of hydatids 

 in the brains of calves, heifers, or cows, it is a great pity 



