The Rot in Sheep. • 135 
Tims wc sec that tlie rato of the progress, as well as the 
duration of rot, are governed by a variety of circumstances, and 
that many of these are so occult and changeable as to forbid 
our predicting with any degree of certainty how long affected 
sheep may bear up against the disease. 
Widi regard to the time of the manifestation of the symptoms 
after flukes have entered the biliary ducts, it is also impossible to 
speak with any degree of certainty. A combination of unfavour- 
able circumstances may give rise to the symptoms in five or 
six weeks ; while, on the contrary, the majority of things being 
favourable, even months may pass before rot is suspected to 
exist. No hasty generalizations should ever be come to on such 
a point as this, and more especially when an action at law may 
hinge on the opinion which is given. A patient inquiry into the 
history of eAch individual instance can alone furnish correct data 
to act upon. 
Post-mortem Appearances. 
The lesions to be observed on inspecting the body of a sheep 
affected with rot will vary according to the progress of the malady, 
be it quick or slow. They will also be modified by the circum- 
stance of the animal having either sunk from the disease, or been 
slaughtered in its early or late stages. The emaciated state of the 
frame often strikes us with surpl-ise, the dead animal appearing 
to be little more than " skin and bone." The wool is found to be 
harsh and dry, and to pull easily from its follicles. The colour 
of the skin is pale, excepting perhaps in places where it assumes 
a purplish Ijue from approaching decomposition. It likewise 
tears readily on the application of moderate force, from having 
lost much of its natural firmness. The visible mucous mem- 
branes are colourless, or have a slight yellow tinge. The belly is 
often large, and gives evidence of containing a quantity of fluid. 
On removing the skin, the fascia covering the muscles 
is frequently found to have a yellowish hue, while the muscles 
themselves are shrunken in size, soft, and flabby. They have 
also lost very much of their normal colour, and do not stiffen as 
is usual. Little or no fat is met with ; but, on the contrary, 
the areolar tissue is infiltrated to a greater or less degree witli 
serous fluid, remarkable for its watery character. This dropsical 
effusion is observed to have accumulated here and there, and 
particularly about the front and lower parts of the neck, and 
around the lower jaw. 
On laying open the abdominal cavity exit is given to a quan- 
tity of serous fluid, the physical properties of which vary con- 
siderably in different cases. In sheep killed for an investigation 
