206 



DISEASES OF SHEEP. 



The method of their reproduction is in unison with 

 their structure, simple in the extreme. Nothing, how- 

 ever, very precise is known about the process. The 

 vesicle which acts as heart and stomach serves also as 

 the reproductive cavity, but how or by what means it 

 is fecundated would be difficult to determine. The 

 young hydatids are found adhering to the inner surface 

 of the parent cavity. When they have attained matu- 

 rity, the parent dies and shrivels, and the young ones 

 begin to eliminate their nourishment from the juices of 

 the quadruped which they infest. 



These entozoa are found in general on the surface 

 of the intestines, between them and their outer mem- 

 brane {peritoneum)^ and on the exterior of the lungs 

 and liver. They are always included in a cyst, to the 

 inner surface of which they adhere by means of two 

 hook-shaped processes projecting from the head. These 

 cysts are always on the surface of the different viscera 

 of the sheep, and in this way may be distinguished 

 from another sacular animal, or rather supposed animal, 

 termed acephalocyst or headless bag, which is some- 

 times found in clusters in the substance of the lungs, 

 liver, &c. and is often confounded with the true hydatid. 



(164.) Causes of Rot. If any one had been asked, 

 thirty years ago, the cause or rather causes of the ap- 

 pearances which pass under the name of rot, he could 

 not have enumerated them even in a day, for at that 

 time each symptom was a disease, and as such was 

 reckoned worthy of a separate and proximate cause. 

 Nor could any person have had the courage to promul- 

 gate a common-sense opinion on the subject; for simple 

 view« regarding the diseases of domestic animals were 



