DISEASES OF THE OX AND SHEEP. 467 



who swallowed water taken from a stagnant pond which con- 

 tained the larvce. 



Next comes the Amphistoma conicum^ a Trematode still more 

 commonly met with. It is provided with a large sucker at 

 its posterior part. It is half an inch long and a quarter of an 

 inch broad. Its eggs are 1*150 inch in diameter. This para- 

 site infests the paunch or first stomach of oxen and sheep, and it 

 is also found in goats and antelopes. The Amphistoma crumeni- 

 ferum is found in the paunch of Indian cattle. The intestinal 

 canal of this parasite has its orifice just underneath the mouth. 

 The A. explanatiim is found in the liver-ducts of the zebra. 

 The A. tuberculatum is so called because it possesses numerous 

 tubercles on the surface of the body. It is found in the large 

 intestine of the ox in India. The Bilharzia hovis and the 

 B. ovis are very much like the one found in human beings, but 

 are a little longer than it. The eggs differ in that they are 

 spindle-shaped. 



The Pe7itastoma tcenioides found in the mesenteric glands of 

 the sheep is born of the eggs of a parasite of the dog which 

 are gathered up by the sheep in their food. Should a dog or 

 wolf devour the entrails of animals in whose glands the parasites 

 exist, the embryoes may adhere to the lips and nose, and then find 

 their way into the nasal cavities. They pass up the nose rapidly, 

 and fix themselves by means of their hooks. In less than two 

 months their generative organs are developed. They remain for 

 a year in the nose of the dog before attaining full development. 

 The next group of parasitic worms which demands attention 

 is that which goes by the name of the Cestoda, or tapeworms, 

 though under this designation the worms known as " measles " * 

 and other bladder-worms, or hydatids, are included, as well as 

 adult tapeworms. The Greek word kestos means a baud or 

 girdle, and this order has acquired this name of Cestoda from the 

 fact that most species in the adult condition resemble a tape or 

 band, from which similarity also arose the name tapeworm. In 

 these worms there is neither mouth, stomach, nor anything 

 resembling an alimentary canal, and the creature therefore de- 

 rives its nutriment by a process of what is called osmosis^ or 

 imbibition. A tapeworm's head is very small indeed. It con- 



* These so-called " measles " have nothing whatever to do with the infectious 

 fever called " measles." 



30 * 



