366 PARASITES OF ANIMALS 



connection with internal parasites as a frequent cause of epizo- 

 otics. My views were criticised at the time with a vigour and 

 warmth well worthy of those who are afraid of advancing 

 epiderniological science too rapidly ; but it seems that so far 

 from my having overstepped the bounds of moderation in this 

 matter I had, in reality, been too cautious. Certainly it can 

 now no longer be said that " the symptoms created by tape- 

 worms in the horse are of little or no consequence." Here, 

 therefore, I repeat, we have made a clear and rapid advance in 

 our knowledge of helminthic disease ; and from the impulse 

 thus given to hippopathology it is only reasonable to look for 

 still further advances in veterinary medicine. By-and-by, the 

 scepticism which not unnaturally exists in reference to entozoa 

 as a frequent cause of death amongst animals, will be dispersed 

 by even yet clearer enunciations regarding the important part 

 these parasites play in the destruction of our most valuable 

 creatures. 



Apart from the question incidentally raised by Megnin as to 

 their origin and mode of development, the presence of larval 

 cestodes in horses cannot be passed over. The common hydatid 

 (Echinococcus veterinorum) , though not of frequent occurrence, 

 is occasionally productive of fatal consequences. Very inter- 

 esting cases are recorded by Messrs Henderson and Kirkman, 

 aided by the valuable comments of Professor Varnell. Mr 

 Hutchinson observed an hydatid in a horse's eye, and Mr Vin- 

 cent noticed lameness, as resulting from hydatids. But one of 

 the most interesting cases of hydatids in solipeds is that 

 described by Professor Huxley, from a zebra that died at the 

 Zoological Gardens in 1852. As stated in Huxley's elaborate 

 memoir (freely quoted in the first part of this work), the liver 

 was found to be " one mass of cysts, varying in size from a 

 child's head downwards." The zebra's death was purely acci- 

 dental, as it broke its neck while at play in the paddock. The 

 long bladder-worm of the horse (Cysticercus fatularis) is entirely 

 unknown to me, and, as before suggested, may be a mere 

 variety of the C. tenuicollis of ruminants. An authentic in- 

 stance of the occurrence of the gid hydatid (Coenurus cerebralis) 

 in the horse is recorded by Gurlt. Lastly, in relation to the 

 question of food, it is worthy of remark that whilst beef, veal, 

 pork, and even mutton, are apt to be measled, the muscle -flesh 

 of horses is not liable to be infested by Cysticerci. This is a 

 fact in favor of hippophagy. 



