OEDEMA OF THE LARGE INTESTINES OF A HORSE. 327 
Examination of the morbid parts .—The blood-vessels of 
the mesenteric glands were engorged with bloody and in many 
of them their coats had given way; extravasation of blood being 
necessarily the result. Effusion of blood, minus the red 
particles, had also taken place between the two layers of the 
peritoneum forming the mesocolon, and among the blood¬ 
vessels at the root of this organ, which from its being in a 
semi-coagulated condition, formed an immense bulky mass. 
Near to the attached border of the intestine several small 
masses of extravasated blood were also observed, and the 
inter-peritoneal space for some distance above the attached 
border of the. intestine was much thickened from effusion. 
I shall now briefly notice the colon itself, which to my mind 
presented a very remarkable appearance. This organ was 
very much enlarged, and when pressed upon with the finger 
it had a peculiar doughy feel. No other peculiarity was ob¬ 
served externally, except its having a yellow tinge, which was 
likewise common to the tissues generally. On opening this 
viscus, both its interior and also the surfaces of the incision 
presented a singular aspect, such, indeed, as I have never 
before witnessed, at any rate not to the same extent. The 
mucous membrane was not only much thickened, but in 
some places it was separated from the muscular coat by 
serous effusion, to the extent of three inches. The muscular 
coat was also thickened by interstitial deposition, and was so 
remarkably fragile that it could be torn with the slightest force. 
The free surface of the mucous membrane was pale in colour, 
with the exception of a few small patches, in which the vessels 
were congested. These patches, from the attrition of the 
ingesta, had become slightly abraded, and might have been 
mistaken for ulcers. In many places the mucous membrane 
projected into the tube in the form of bags, varying in size, 
here and there extending around the whole of the interior of 
the intestine, thus materially diminishing ite calibre. 
Throughout the whole length of the bowel there was, how¬ 
ever, no indication of any inflammatory action. 
In accounting for these morbid changes taking place, may 
we not suppose that some material— miasmata, for example, 
had been taken into the system from without, which, acting 
as a ferment to the whole circulating mass of blood, had 
thereby contaminated it ? Or may not some morbific matter 
have been generated in the blood, and thus produce similar 
results, if not eliminated from the system ? Or, on the other 
hand, may not the usual products of the metamorphoses of the 
tissues, or even of the blood itself, be retained in the circu¬ 
lation, and act as a septic poison ? The blood, being altered 
