DISEASES OE THE OX AND SHEEP. 477 



the cause of Husk or Hoose in cattle, and the Strongylus 

 JUaria^ which attacks sheep and especially lambs. There can 

 be little doubt that the young of the strongyles, which occasion 

 verminous bronchitis of calves and lambs, undergo their pri- 

 mary changes of development either within soft mud alone, or 

 within the bodies of earthworms or small slugs or insects, and 

 other minute creatures among the herbage, or possibly within 

 the bodies of larval insects or other animals inhabiting ponds, 

 ditches, and streams. Some of these strongyles live within the 

 bodies of animals, some in the slime of animals, some infest 

 plants, while some are entirely free. Some of those which live 

 in the interior of animals lead a free life in their larval state, 

 passing a certain grade of development in mud and water, while 

 some pass through certain larval changes of growth within the 

 bodies of insects and other creatures. Several other strongyles 

 infest the sheep, the ox, the goat, and stag. The strongyles, 

 of ruminants include the Strongylus micrurus, the S.Jilaria, and 

 the S. rufescens. The S. hypostonus infests especially the 

 intestines of the sheep. The larvee of this strongyle, which 

 are rod-shaped, live in mud. The S. certiuus is nearly ono 

 inch in length. This worm may infest the intestines of the 

 sheep in large numbers. The S. Jilicollis, or slender-necked 

 strongyle, is met with in the small intestines of sheep, and 

 especially in those of the lamb. The S, contortus^ or twisted 

 strongyle, may be present in the abomasum or fourth stomach 

 of the sheep and lamb, and in the goat, usually together with 

 the S.Jilaria. 



The S. radiatus resembles the S. cernuus. This worm infests 

 the gall-ducts and the first portion of the small intestine (called 

 the duodenum) of young cattle, and it gives rise to a fatal 

 epizooty among young oxen. The S. injlalus infests the large 

 intestines (the colon) of the ox. The S. ventriculosusy or 

 swollen strongyle, infests the small intestines of the ox. The 

 male S. gigas is twelve inches long, while the females may be 

 upwards of three feet in length. The S. venulosus, or veined 

 strongyle, is rarely met with. It has been found in the small 

 intestines of a goat. The females are three-quarters of an inch 

 in length, the males half an inch long. The trichinidsB are 

 ■?ery minute, the mature male being one-eighteenth of an inch 

 in length, and the mature female one-eighth of an inch long.. 



