DISEASES DUE TO INTEENAL PARASITES. 227 



certain extent throughotit the different parts of the world where 

 the land is swampy and subject to floods. 



M. M. Hamont, in an essay on this subject, states that "it 

 assumes its most serious character after heavy rains and extensive 

 floods, and in wet countries covered with aquatic plants. It 

 affects animals of different ages and in all seasons. It appear? 

 every year in Egypt after the fall of the Nile, and it follows and 

 keeps pace with the subsidence of the waters. In the superior 

 parts of Upper Egypt it commences about the end of July, near 

 Cairo in August, in the environs of the capital in October and 

 November, and during the months of December, January and 

 February in the Delta. It is most obstinate and continues long- 

 est in the neighborhood of the confluence of the waters. In 

 Lower Egypt it lasts about 120 to 130 days, and it disappears 

 soonest and is least fatal when the rise of the Nile has not been 

 considerable. Desolation and death accompany it wherever it 

 passes. The Arabs say that this pest annually destroys 16,000 

 sheep in Egypt. Its victims usually perish on the twenty-fifth, 

 thirtieth, thirty-fifth or fortieth day after the apparent attack." 

 From this extract we can readily understand that it is a particu- 

 larly fatal disease, and that it being of so rare an occurrence 

 in the United States of America is a cause for self-congratulation 

 among the flock owners of this country. 



Symptoms. 



The primary symptoms are slight. Instead of the animal 

 losing flesh it appears to increase in weight, the appetite remains 

 good, the tendency to fatten being due to the better assimilation 

 of the food products, owing to the increased secretion of bile 

 caused from the irritation due to the young liver-flukes in the 

 bile-ducts and liver, and this very tendency to fatten in the first 

 stages of the disease has led feeders, notably the celebrated 

 Bakewell, to purposely expose the sheep intended for early 



