Experiments on the Development of the Liver-fluke. 21 
and a large number of them collected and examined at the time 
when it is known that the germs of the fluke were about the 
ground, but no cercaria? were discovered. In the irrigation 
trenches and the two brooks many kinds of water-snails were 
discovered, and some of them (L. peregcr) contained trema- 
todes, but none traceable to Fasciola. 
Stratton Audley. — In a lamb's liver from this place a great 
number of minute flukes were discovered, and as they had 
evidently entered the liver quite recently the case was followed 
up, and the ground where the lamb had been reared was visited. 
The farmer had lost all his ewes by rot the previous winter : the 
lambs had to be weaned very soon, and the mothers sold for 
a few shillings each. For the last three months the lambs had 
been kept exclusively in four fields, which lay partly on the 
Cornbrash and partly upon the Oxford Clay. The ground on 
the whole seemed in good condition, but in some of the lowei 
parts upon the clay was obviously damp, as was shown by a few 
scattered rushes growing there. No part of the ground was 
subject to long-standing floods, but during heavy rains the 
water had some difficulty in getting away, and on such occa- 
sions would stand for a short time on the lower parts of the 
meadows. About an acre had been so covered for a few hours 
after some heavy rain at the end of August, four weeks previous 
to my visit. At the bottom of the fields flowed a small rivulet, 
but this contained nothing beyond Gammarus pulex and two or 
three small grey slugs, which were bathing themselves after the 
wont of this species. The ditches were mostly clean, but one 
contained many specimens of Succinea amphibia and Planorbis 
■discus, and after much search two or three specimens of Lim- 
ncpus pereger, L. truncatulus and Pisidium were discovered. 
The black slug was scarce, and only one specimen could be 
procured ; but the most striking feature in the moUuscan fauna 
was the excessive abundance of Limax agrestis scattered over 
the fields and crawling up the stalks of grass. More than thirty 
of these grey slugs were dissected, but nothing could be found 
in them. The only larval trematodes obtained here were 
Leucochloridium in Succinea, Distoma sp. in Gammarus, and 
in one only out of twenty-three specimens of Planorbis discus 
a species of Histrionella, apparently undescribed as yet. It is 
found in small flask-shaped rediae, the body is depressed and 
oval, the hinder border emarginate ; on the back are two, or at 
a later stage three, black eye-spots. The tail is simple and 
filiform, two or three times as long as the body, and very con- 
tractile, and the animal shows a great tendency to encyst upon 
surrounding bodies. The Histrionella might possibly have some 
connection with Fasciola, but most piobably has not. 
