The Rot in Sheep. 
79 
the biliary ducts and intestines, and therefore in their ])erfected 
condition, than we can conceive it would be possible for a sheep 
to obtaui during- a summer's grazing-, and exhibited them to an 
animal, using a little water as a vehicle. The quantity was not 
less than a teaspoonful ; and as it is often impossible to count the 
number of ova in the field of the microscope, which may be 
contained in a drop or two of water, we can scarcely imagine the 
hundreds of thousands which were thus given to the animal. 
The sheep was kept six months before being destroyed, and, on 
examining its liver and other organs, not a single Jluhe teas found. 
This negative result was exceedingly valuable, and it fully 
confirms similar experiments which have been carried out in 
Germany and elsewhere. 
Gerlach, who is connected with the Berlin School of Veteri- 
nary Medicine, has had recourse to experiments of the same 
kind, and invariably with the like result ; thus showing that the 
ova of the fluke when introduced into the digestive system of the 
sheep, will not develop into or generate flukes. It may be said 
that we have almost a continuous illustration of the fact in the 
enormous quantities of fluke eggs which enter the stomach and 
intestines of dogs belonging to butchers, farmers, and others, from 
eating the livers of rotten sheep. These animals suffer no ill 
effects thei-efrom, and we have never met with the entozoon in 
the biliary ducts of the dog, although our opportunities have 
not been a few in making autopsies of this animal. No doubt 
many persons will, object to this illustration, on the ground that 
the dog is a carnivorous creature, and therefore animal products 
of this or any similar description would be quickly digested in 
his stomach. We admit the force of the objection ; but we may 
reply, that flukes have frequently been found in some of the 
carnivora, both wild and domesticated, and also in the pig-, who 
is, it is true, omnivorous, but whose digestive powers are not- 
withstanding- little inferior, if any, to those of the carnivora. The 
entozoon has likewise been occasionally met with in man, another 
of the omnivora. It may be affirmed, therefore, that all these 
theories have been more or less at fault, and that it is only 
within, comparatively speaking, a very short space of time that 
we have approximated to anything like a correct explanation of 
the cause of rot. 
The year 1837 witnessed the publication of the best work ex- 
tant on the diseases of sheep, from the pen of the late Mr. Youatt, 
entitled. Sheep; their Breeds, Management, and Diseases. It 
contains a lengthy article on rot, in which Mr. Youatt not only 
gives his own experience, but culls from nearly all those who 
had Avritten upon the subject. He comes to the conclusion that 
the disease is due to the inhalation of miasm, and hence that it 
