Tlie Rot in Sheep. 



We now come to an explanation of the cause, which ought 

 not to be too hastily rejected. It is founded on a knowledge of 

 the manner in which many entozoic worms are propagated, 

 namely, directly by ova, which in due time give birth to young 

 worms precisely like the parent. Long prior, however, to the 

 period we are now alluding to — 1836 — it was known to scientific 

 inquirers that the liver-fluke was an oviparous creature, and that 

 it deposited an enormous number of eggs (see fig. 9) within 

 the biliary ducts. It had also by some practical writers on the 

 diseases of sheep been stated that flukes might originate from 

 the eggs of " some insects " which had been deposited on the 

 herbage, particularly of wet soils. Others, however, far better 

 acquainted with natural history, suggested that the existence of 

 the fluke in the liver was probably due to the ova of the parasite 

 being conveyed into the digestive organs of the sheep while 

 feeding on particular grounds. The extensive promulgation 

 of this opinion is chiefly due to the labours of Mr. E. King, 

 who published some papers on the subject in the 4 Scotch 

 Quarterly Journal of Agriculture ' and in the * Agricultural 

 Magazine.' We have been unable to learn whether Mr. King — 

 who seems to have resided in Oxfordshire, but who wrote from 

 the 44 Steam-carriage Station, Hammersmith " — had received a 

 medical education or not ; nevertheless he writes like a person 

 well informed on the general structure and functions of the animal 

 frame, as also on the subject of natural history. We give the 

 following quotations from his writings : — 



" Flukes' eggs float in the gall, and go with it out of the gall-bladder into 

 the intestine. Here they commingle abundantly with the contents of the 

 intestines ; and if the sheep be very full of flukes, the eggs so abound in the 

 contents of the intestines that the smallest portion of a sheep's droppings 

 taken up upon the point of a penknife and placed upon the object-glass of a 

 microscope and wetted with a drop of spring water will show several of them. 

 A buyer of sheep for stores, if he can find one fluke's egg by this mode of 

 examination, would do well to decline purchasing such sheep. 



" Hasty rain liberates flukes' eggs from sheep's droppings, and splashes 

 them round about upon the circumjacent herbage ; but healthy sheep, pro- 

 tected by their nose, are in little danger here of swallowing these eggs. The 

 next shower, or perhaps the fag-end of the shower which liberates the eggs from 

 the sheep's droppings, carries the eggs down to the earth or into the crowns of 

 grass plants. If the soil be sandy or from any cause porous, the water soaks 

 into the earth and leaves the flukes' eggs upon the surface, where they perish 

 either by frost or desiccation. Such ground is therefore called sound land. 



" If, on the contrary, the soil be very compact and clayey, so that the rain- 

 water cannot soak into the earth, it draws off upon the surface, floating with 

 it the flukes' eggs into the furrows, the ditches, the brooks, &c, and the nukes' 

 eggs go wherever the flood- water goes. These eggs are so nearly of the same 

 specific gravity as water that the least motion of the water keeps them moving ; 

 but they will settle to the bottom gradually wherever water is perfectly at 

 rest. Wherever flood-water, carrying lots of flukes' eggs, finds perfect rest, 

 there these eggs will settle; and many of them settle into holes, where, after 



