260 Liver Rot of Sheep 
few peregra. Lower down peregra became more abundant and tended 
to occupy the centre of the stream while truncatula kept more to the 
sides, while near, and in the pond, upon the soft mud peregra was very 
abundant and truncatula totally absent. Newts swarmed in the pool. 
By the date mentioned the water had already become somewhat 
reduced and on the 31st, many specimens oi'truncatula were observed 
crawling upon the damp earth among the grass tufts bordering the stream 
and quite 18 inches from the water: the weather was showery. By 
April 28th this stream was dry, but in the damper hollows peregra was 
still alive. None were crawling but lay with the shell mouth pressed 
to the mud and the animal somewhat withdrawn. L. truncatula was 
scattered here and there chiefly along the grassy margins. Fifteen 
placed in water crawled almost immediately; the ground was not very 
dry, being sheltered by grass. 
May 1st. The lower portion of the stream had been practically 
cleared of peregra probably by Moles which had furrowed up the mud 
in all directions. Higher up there were no signs of Moles, and shells were 
abundant, some already dead and empty. 
May 3rd. A few peregra could still be revived in water, while of 
ten truncatula placed in a tube three proved to be quite dead, but the 
rest, although considerably withdrawn within their shells, soon expanded 
and in three hours the water swarmed with cercariae. From some of 
the emptied shells of peregra I obtained larvae, probably those of the 
beetle Drilus flavescens L. 
Between May 3rd and 7t.h there was considerable rainfall and such 
molluscs as survived were crawling about as usual (by the latter date). 
I was then unable to re-visit this place until June 16th and by that 
date the stream was quite dry and not a single shell of either species 
could I find. From this date there was no rainfall sufficient to disturb 
the drought conditions. On Oct. 23rd the ditch was almost as hard as 
the road and covered with Agrostis, while the pond below had dried 
and had been cleaned out (the first time for years). 
Both stream and pond were full of water on Jan. 28th, 1915, but 
no mollusca were discovered and another examination on March 18th 
yielded no betfer results, but by May 15th truncatula had appeared in 
the upper portion and a few peregra in the lower, and in June truncatula 
was he'avily infected with Distomum larvae. The stream again dried 
and remained so until the middle of November; though a few peregra 
were still alive amongst mud in the pond below on Oct. 9th. 
L. truncatula re-appeared by Feb. 1st, 1916, and were quite abundant 
