ON THE PROPAGATION OF ROT IN SITEEP. \)7 
disturbed eggs at the bottom. To the remains add a fresh quan- 
tity of clean water, by which the eggs will be cleaner washed, 
and their reddishness refreshed. After the eggs shall again have 
settled, the bulk of the water may be once more steadily poured 
off, and the remainder, containing the eggs, poured upon a paper 
filter, through which the water will drain away, leaving plenty 
of eggs upon the paper. In this manner I have collected a 
thimble full of eggs from the liver of one sheep. 
The perfect eggs of a fluke seen through a tolerable micro- 
scope resemble more that of a duck than that of a hen ; it is less 
pointed at the lesser end than that of a hen. As far as I could 
judge from measuring with an insufficient micrometer, the shorter 
diameter of these eggs is about a three-hundredth of an inch, 
and the longer diameter about a two-hundredth of an inch. The 
experimentalist should make himself very well acquainted with 
the character and appearances of these eggs, so that he shall 
be able to recognize them wherever he may find them. All his 
labours will be unscientific and unsatisfactory until this trifling 
difficulty shall be overcome ; whence arises my solicitude to 
enable him easily to collect plenty of sound eggs for the use of 
his object glasses. By assiduously cultivating his acquaintance 
with these eggs, apparently very insignificant particles, he may 
justly hope ultimately to save millions of heads of sheep, millions 
of fleeces, and many thousands of pounds to the revenue of his 
country : these tiny eggs lose their insignificancy under this re- 
flection. The importance of these minute ova will be enhanced 
in the mind of the philosophical herdsman, in proportion to the 
attention he may think fit to bestow upon the following and 
similar views : — 
First. — If we can discover thousands of flukes* eggs hatching 
or giving out a young fluke in the gall of a sheep already dis- 
eased, but while feeding upon perfectly sound pasture, we shall 
be sure then that thousands of these eggs hatch in the liver of 
a diseased sheep without first passing off with the bile by the 
intestines. Hence we shall see, that if by any chance a pre- 
viously sound sheep become infected with only two flukes, each 
being both male and female, and abundantly prolific, its liver 
will in the course of a season become thronged with myriads 
of these vile inhabitants. 
Secondly. — If we can discover thousands of these eggs float- 
ing through the ductus communis choledochus with the bile of 
the animal, and find them commingling uninjured with the ex- 
crementitious contents of the intestines from the duodenum to 
the rectum, and find them quite sound and healthy in the drop- 
pings of an unsound flock every where, so that the least modi- 
vol. ix. o 
