20 Experiments on the Development of the Liver-fluke. 
opaque structure, seemingly made up of granules arranged in 
rounded masses. These granules are dissolved by acids without 
effervescence, leaving an albuminoid basis ; one would most 
naturally refer them to the lateral excretory organs, but no 
vessels can be distinguished. The cercaria is very active but 
soon comes to rest, and shows a strong tendency to encyst 
itself upon surrounding objects. It contracts so as to assume 
a spherical form, and exudes a mucous substance, containing 
numerous opaque granules, which are those previously forming 
the white lateral masses. The cysts are snowy white by reflected 
light, but on rupturing them the included distoma is found to 
be quite transparent.* 
The structure and habits of this cercaria render it possible 
that it may prove to be the larva of Fasciola kepatica, but want 
of material has prevented my testing the question by giving the 
cysts to rabbits. I intend, however, to pursue this case further, 
and am indebted to the Earl of Abingdon for free access to his 
estate in investigating the source of the infection. 
Frilford. — Certain low-lying fields were visited here which 
gave the rot in 1879 for the first time during twenty years. 
The sheep had been divided into three flocks, and one of them 
placed on meadows near two small streams, in the middle of 
August. All these were badly rotted and had to be killed 
before the end of October, This part of the ground is flooded 
regularly in the winter, but such a flood is not dreaded : it 
was the summer-floods of 1879 which gave rise to so much 
mischief. 
On some adjacent fields one of the other flocks was rotted, as 
well as heifers, though not so rapidly. This land does not lie 
so low, but is irrigated, and is very damp. Lambs were placed 
here last summer, for, as there had been no summer-flood, it was 
supposed to be quite sound. The owner was strongly urged by 
Professor Rolleston to remove them to higher ground, and all 
except three were accordingly removed. These three were 
kept, by way of experiment, upon the fields until the end of 
August, when, food becoming scanty, they were driven on to 
drier ground. One of these was slaughtered two or three weeks 
later, and was found to contain young flukes. 
Three species of land-molluscs were found here in great 
abundance, viz. Arion ater, Limax agrestis, and Succinea putris, 
* The tissues of the cercaria contain numerous rod-like corpuscles 0 006 mm. 
long, closely restmbling bacteria in form but without movement. Do Filippi 
(I.e. vol. xvi. p. 432) found similar corpuscles in the cercaria of Amphisfoma suh- 
clavatum, and as they disappear in the adult he suggested that tlicy might aid in 
forming the cyst. But I found them still present in cercaria; whicli had been 
encysted a fortnight. 
