The Hot in Sheep. 



11 



for when there is no dew or other wet upon the grass, the snail 

 or slug cannot feed, and therefore is never abroad in the dry part 

 of the day ; so that in dry weather sheep are not in danger of the 

 rot by these creatures." 



Ellis, in the work previously alluded to (1749), dwells par- 

 ticularly on the rotting of sheep by their being pastured in 

 meadows in which swampy places exist, and also in such as have 

 a clay subsoil, rendering the surface retentive of moisture. He 

 speaks likewise of the injurious effects of the animals eating 

 " Spear-wort," " Rennet-wort grass," " Penny-grass," " Knot- 

 grass," " Mildewed-grass," and " rank, flashy grass," and a 

 certain weed called " bean- weed, which grows in the mossy 

 grounds of vales." He asserts that " sheep do not take the rot 

 even when land is flooded, but they take the cause of it after the 

 waters are abated ; for, as the sheep by this means have been 

 kept off the grass for some time, when they come on it they meet 

 with a slime and dirt on it, which brings them under the rot ; 

 for nothing rots a sheep or any other creature more than slime 

 and dirt." 



Ellis is more distinct in his statements about the injurious 

 effects of " plaise-worms " — flukes (see jig. 2) — in the liver, than 

 any English author prior to his time whose writings we have 

 perused. He narrates a case of a very large number of these 

 entozoa being found in the liver, and, after describing their size 

 and other peculiarities, proceeds to give the following hypothesis 

 of their production : — " These destructive worms are, I suppose, 

 bred by the corruption of blood, for the blood must be first 

 vitiated by the sheep's feeding on unwholesome grass or weeds, 

 or by poverty or otherwise, from whence are bred the seeds or 

 eggs of plaise-worms, which, circulating with the blood, make 

 their nest or lodgment in the fountain ; that is to say, in the 

 liver of the beast, where, if they cannot be killed, they will eat 

 till they kill the sheep." 



It will be unnecessary in this place to combat Ellis's views of 

 fortuitous generation, or to expose his errors of physiology, our 

 object being rather to show that a distinct opinion existed in his 

 time, that rot was associated with the presence of flukes in the 

 biliary ducts. 



Passing by several authors of minor importance, whose works 

 contain nothing original on the subject, we come in the next 

 place to the celebrated Bakewell, of whom it is said that he often 

 intentionally produced the rot in his sheep, to prevent their 

 being used for breeding purposes subsequently to their sale. 

 We find the authority for this statement, as well as an account 

 of Bakewell's opinion of the cause of the disease, in Arthur 

 Young's Farmer s Tour in flic Blast of England^ vol. i. 



Young thus writes : — " Relative to the rot in sheep, Mr. Hake- 



