124 THE INTERNAL PAEASITES OF 



of high interest to the helminthologist, as being the only 

 thorn-headed or acanthocephalous worm liable to infest 

 our domesticated animals. The full-grown female has 

 been known to acquire a length of 18in., the thickness of 

 the body equalling that of the little finger. The males 

 seldom measure more than 3in. from head to tail. This 

 worm, when present in any considerable numbers, quickly 

 reduces the strength of the porcine host, occasionally 

 causing death by perforation of the bowel. 



Parasites of the Gat. — So many persons are interested 

 in the welfare of this useful house-pet, that I am con- 

 strained to say a few words respecting its internal para- 

 sites, several of which it shares in common with the 

 dog. 



Every owner of cats must have, from time to time, 

 noticed the frequent occurrence of sickness amongst 

 these animals ; such fits of vomiting usually terminating 

 in the expulsion of worms from the mouth. The entozoa 

 causing these attacks are small lumbricoids, or nematodes 

 (Ascaris mystax) occupying the stomach; the females 

 being nearly twice as long as the males, and sometimes 

 measuring as much as four inches. In the dog, as we 

 have seen, a variety of the same worm grows to the 

 length of half a foot. It may also be ^dded that five or 

 six cases are on record of the occurrence of this parasite 

 in the human body. 



Respecting other nematodes infesting the cat, I may 

 notice a species of strongle (Dochmius tubceformis) occa- 

 sionally found in the upper intestine, and also the flesh- 

 worm {Trichina spiralis) , which has frequently been reared 

 in this animal by experiment. 



In the wild progenitor of our domestic cat the pre- 

 sence of two other nematodes has also been pointed 



