DISEASES OF THE OX AND SHEEP. 465 



likewise serve that same purpose. The liver-fluke occurs both 

 in the United States of America and in Australia, notwith- 

 standing that the LimncBus truncatulus has not been found, 

 and is probably not present, in either of those countries. Hence 

 we cannot but think it probable that other snails, and possibly 

 also slugs, may act as intermediary hosts. 



It will clearly be seen, then, that one sheep cannot directly 

 take the disease from another sheep, and it seems also that one 

 snail cannot be directly infected by another snail. We must 

 also bear in mind that hares and rabbits, as well as cattle and 

 sheep, distribute the eggs of flukes far and wide, and that they 

 also may be conveyed by manure, by the feet of men and dogs, 

 and by running brooks. The snails also, after they have been 

 infected, are doubtless also largely distributed by rivulets, rivers, 

 or floods. 



Sheep afiflicted with this disorder ought not to be kept on 

 damp ground, because the eggs need moisture in order to main- 

 tain their vitality, and hence have not the same chance of living 

 if they fall on dry soil. For this same reason all damp pas- 

 tures ought to be thoroughly drained, so that there may be no 

 collections of stagnant water in which the eggs can retain their 

 life. 



It is of especial importance that all land should be well- 

 drained, and that the practice of fattening sheep on pastures 

 liable to cause sheep rot should be at once discarded. It seems 

 that Lord Penrhyn, in 1881, had not had a case of sheep-rot 

 for fifteen years, and this he attributed to the keeping his sheep 

 off wet land, his dykes well dug out, his land thoroughly 

 drained, to the providing of good hay for the winter, to salting 

 the hay when ricked, and to having rock-salt within the reach 

 of the sheep. Moreover, salt or lime should be scattered on the 

 herbage in pastures on which it is suspected that the disease 

 may break out. If the land be thus dressed with lime or salt, 

 the snails will be in some measure destroyed. These useful 

 substances should therefore be especially scattered about along 

 the courses of brooks, and by the sides of ponds and ditches, 

 and on or near any marshy places. More particularly should 

 flooded lands be dressed, since a flood after subsidence may 

 leave snails scattered broadcast. 



The mixing of salt with the food of sheep and cattle which 



30 



