I 



XXXII. 

 ON THE ROT IN SHEEP. 



The Englisli Lake District presents us with as simple a case for 

 the investigation of the cause of rot in sheep as any other portion 

 of the wide area over which that disease has spread, with, perhaps, 

 the exception of such isolated localities as the Faroe Islands ; for 

 sheep abound upon its thousand hills, while the species of snails 

 and slugs are but few, and the conditions of its geological form- 

 ation, of its fauna and of its flora differ as widely from those of 

 many other regions within our four seas similarly affected as it is, 

 all thiugs considered, possible for them to differ. Having occasion 

 to visit the district in question last week, I used the opportunity 

 for making a few enquiries of the farmers and shepherds there as to 

 the natural history of this plague. These enquiries were of the 

 simplest kind, anybody can repeat them, and I cannot but think 

 that the answers he will receive will incline such an enquirer to 

 think that a strong a prion case is made out in favour of the view 

 put forward in ' The Times ' of April 7, to the effect of identifying 

 the black slug [Arion ater) or the gray slug [Limax agrestis) as one 

 necessary link, in the chain of causes concerned. I found the 

 natives as intelligent and observant as I have found them to be 

 any time during the last thirty-four years upon natural history 

 questions ; and I very rapidly got the following facts deposed to by 

 them without any prompting on my part : — 



I. The fluke disease is a disease of low grounds, and notably of 

 pastures liable to be flooded. 



2,. But not exclusively of pastures liable to be flooded ; for, what 

 is of special consequence as going some way towards eliminating 

 the pond snails [Limnaeus pereger) and others from the charge of 

 sharing in the causation of fluke disease, the pasturing of sheep in 

 a stubble rich in the ^ melancholic poisonous green,' which a wet 



