2l6 
TODD AND WOLBACH. 
fluids of horses infected with Swamp Fever for a specific 
animal parasite; none has been found. 
The virus of Swamp Fever can be transmitted to equines 
by the inoculation of blood from an infected horse. Infected 
blood, or blood serum, is still infective after having been 
passed through a porcelain filter; the virus, consequently, 
is, probably, ultra-microscopic. 
V. Morbid anatomy. A. Gross appearances. — The 
lesions found in animals which have died of Swamp Fever 
are usually surprisingly few in number and their severity is 
slight. If, as usual, the disease has lasted for some time 
the body is wasted and the mucous membranes are anemic. 
The skin may be abraded and cut, through the animal's 
struggles during the period when it was too weak to rise. 
There may be edema of the dependent portions of the body, 
such as the feet, sheath, abdomen, lower part of the legs 
and the side upon which the animal was lying while it was 
in extremis. If the disease has been a very chronic one, 
the muscles are wasted and pale, and there is very little fat. 
The peritoneum, the pleurae, and the pericardium may con- 
tain a small amount of serous fluid ; both the visceral and 
parietal surfaces of the abdominal peritoneum and of the 
pleurae and pericardium may be dotted, more or less closely, 
with petechias. The heart is often enlarged ; it may weigh 
as much as twelve or fourteen pounds, and its muscle may 
be pale. The clot contained in the heart, and in the great 
vessels, is often very pale and yellow (chicken-fat clot) ; 
frequently the fat about the auriculo-ventricular groove is 
infiltrated with a yellowish, gelatinous edema. The lungs 
are unchanged. The liver may be congested and enlarged ; 
sometimes it seems to be degenerated. The spleen is often 
considerably enlarged and weighs as much as six pounds ; 
it is sometimes congested and friable and may contain 
infarcts. The kidneys, often unchanged, are sometimes soft 
and friable. The lymphatic glands, especially those of the 
various intra-abdominal groups, are often enlarged and very 
