352 Veterinary Medicine. 



i860 the western and southern countries lost f ths of their flocks 

 (Simonds) and in 1862, 500,000 sheep perished in the United 

 Kingdom (Gamgee). In 1876 it killed 40 per cent, of the cattle 

 of Slavonia (Neumann), and sheep of the value of 1,500,- 

 000 francs in Alsace-Lorraine (Zundel). In 1882 Buenos 

 Ayres lost 1,000,000 sheep (Wernicke). Since 1855, when in- 

 troduced by imported German sheep, it has prevailed in the damp 

 pastures of Victoria, Australia (Veterinarian), and in 1891 one 

 owner lost more than 10,000 sheep. 



The wet seasons (autumn and spring) are notorious for the 

 prevalence of the disease. 



So with inundations : after the overflowing of the Nile the sheep 

 suffer after they advance on the pastures from which the waters 

 have subsided, so that the period following the fall of the river, 

 is the period of ' rot. ' 



Wei, marshy, undrained pastures , such as deltas, low islands, 

 bottom lands, basins with no dependent outlet, drying ponds and 

 lakes of fresh water are especial homes of the fluke and of result- 

 ant ' rot.' The same applies to unimproved clays and other im- 

 pervious soils in which the water accummulates and remains. In 

 France the damp bottom lands of the Sologne, Berry, Gatinais, 

 and Gaiscony ; in England the fens of lyincolnshire, the Ouse 

 Valley and the sea coasts of Kent and Sussex ; in Germany the 

 Spree and other river valleys ; in Victoria, Australia, the damp 

 sour grass pastures ; in America the bottom lands in the Southern 

 States, in Nicollet Co., Miss., Conecuh Co., Ala., Polk Co., 

 Tenn., Madison Co., Va., Kent and Cayahoga Co., O. ; in Asia 

 on the damp rich soils of Siberia, Afganistan, Thibet, etc., and 

 in Northern Europe those of Finland are spheres of distomatosis. 



It is worthy of notice that the affected sheep, when removed to 

 high, dry pastures, or to salt marshes, fail to transmit the para- 

 site to healthy sheep. The disease may prove fatal to them, but 

 healthy sheep which mingle with them escape. This is due to 

 the absence of the fresh water snails, the necessary hosts of the 

 encysted brood capsules and the rediae. 



A flock which is folded at night and kept off the pasture until 

 the morning dew has evaporated will sometimes escape. The 

 same is true as regards lung worms. The embryo worms and the 

 unencysted cercaria alike retreat from the dry vegetation. Light 



