0. L. ^Yalton 
239 
carefully studied (the results will be found under L. truncatula). The 
last outbreak of liver rot was by no means so widely distributed, nor 
was as much havoc wrought as was the case in some previous epidemics. 
Nevertheless, a number of flocks were decimated, and considerable 
loss occasioned among the others, particularly in the Dyfi Flats and s.E. 
regions. 
It would seem that both host and parasite are naturally able to 
maintain themselves permanently within the Area in favourable situa¬ 
tions, which, given suitable conditions, serve as centres from which they 
may spread. 
A considerable number of livers infected with D. hepaticum came 
into my hands, and it was once reported to me from cattle, although 
I failed to obtain any of the specimens, which were stated to have 
been very large. 
It is probable that in certain regions the majority of the sheep 
harbour a few of these parasites, which however, are seldom present 
in sufficient numbers to cause serious disturbance. Drafts from these 
flocks sold each autumn distribute the ova of the flukes over a large 
area thus tend to perpetuate the cause of future trouble. 
I have nothing to add to previous descriptions of the parasite or the 
disease; but in connection with what has been said above, I may add 
that, although ewes may suffer from flukes for several years and even 
finally find their way to the slaughter house as “fat,” yet the livers of 
many are found to be atrophied and hardened to the consistency of 
leather. 
I do not know of any local name for the fluke other than the general 
term pryfecl, a worm, the disease, however, in addition to the word rot, 
is known by several terms, and of these pwd is the most general, and 
really refers to the dropsical swelling that frequently appears beneath 
the lower jaw consequent upon the lowered position of the head while 
grazing. Pwdri (rotten) is often applied to the condition, and the word 
“rot” finds its equivalent in ivedi rotio. To the North of the Area the 
word jwck is used for liver rot. 
Methods of Combating the Liver Fluke. 
The presence of the disease has a considerable effect in modifying 
the systems of sheep farming, various methods being adopted to mitigate 
and prevent its appearance, the following being the most usual: 
1. A few farms possessing wet clay soils capable of giving severe 
general infection have given up keeping sheep. 
its—2 
