452 Second Report of Experiments of the 
composed of coarsely granular cells. Leuckart does not consider 
that this cercaria has any connection with the liver-fluke, partly 
because he did not detect any spines upon the cuticle. I have 
seen the same larval trematode since writing my former paper, 
though not in sufficient quantity to allow me to try feeding 
experiments, and I am able to say that the cuticle of the oldest 
cercaria? is beset anteriorly with spines ; in the less mature 
cercaria? they could not be seen. It appears to me that 
this form is to be regarded with suspicion for the following 
reasons : 1. Its anatomical characters are not contradictory to 
the idea that it may prove to be the larva of Fasciola ; the 
cuticle of the anterior part of the body is finely spinose, and the 
oral and ventral suckers are of nearly equal diameter, the 
ventral being sometimes a little the larger. The lobed lateral 
organ I regard, for a reason already given,* as merely a passing 
larval character. 2. The rediae show a greater resemblance to 
the young rediae descended from fluke-eggs, as I have observed 
them, than do those containing tail-less distomes. The resem- 
blance indeed is very striking. 3. The cercaria has the sus- 
picious habit of encysting itself upon water-plants, grass, &c. 
Moreover, I have twice met with this cercaria in the course of 
my investigations — on one occasion in almost the only mollusc 
that could be found on the scene of an outbreak of the liver-rot 
at VVytham, whereas I have never found the tail-less larval form 
mentioned by Leuckart. Experiment must decide whether this, 
or the tail-less form in question, or some other cercaria, is the 
juvenile form of the liver-fluke. 
It gives me much pleasure to take this opportunity of thanking 
Dr. Acland for kindly permitting me to use the Sanitary Labo- 
ratory, in which I am continuing my experiments. 
It would greatly assist me in bringing my researches to a 
J,, g speedy and successful termination, if 
■ any gentleman who is interested in 
the question could kindly forward to 
me, at the University Museum, Oxford, 
gatherings of snails, more especially of 
Limnoius perccjer and L. t7-uncatulus, 
from the scene of any well-marked 
(1). rmna,«spe,T.7«-, an average si^o- f^csh Outbreak of flukc-diseasc, or 
cimcn natural si/.e (,2) i.ininans from grouud which is known alwavs 
trunmtulus, twice tlie natural size. , ~ -i i 111 
(3). Tlie same. A coniinon variety, tO glVC the rot. 1 he SUails should be 
natural size. . , , 1111 
as numerous as possible, and should 
particularly include young and half-grown examples. The 
accompanying figures represent the two kinds of snails, towards 
* ' Eoyal Agriculturul Society's Journal,' vol. xvii., 1881, p. 20. 
