88 THOMPSON YATES AND JOHNSTON LABORATORIES REPORT 
fluid was generally increased in amount. The lungs were normal, the heart flabby. 
There was generally effusion in the pericardium and pleural cavities. The liver was 
usually much congested, its vessels enlarged and filled with both dark fluid and 
clotted blood. 1 he capsule was very often thickened. 
The spleen in all the animals was very much enlarged, being sometimes four or 
five times its normal size. On section it often showed haemorrhages, the pulp being 
dark-red in colour. The follicles were usually hyperplastic and prominent. 
The kidneys appeared normal. 
The lymph glands were enlarged as a rule, and whilst few appeared normal, 
most of them were light or dark-brown in colour with greyish intersecting bands of 
hyperplastic connective tissue. 
The bone marrow in most cases was dark-red in colour with a few grey 
islets in it. 
Microscopical Examination 
In some of the vessels of the grey matter of the brain and spinal cord, the 
perivascular spaces were filled with red blood corpuscles, pigment granules, and a 
few leucocytes. The tissue around the vessels was often destroyed. 
Spleen. The most striking feature was the extreme congestion which, in the 
majority of the cases, was most marked in the periphery, where sometimes nothing 
could be seen but red blood corpuscles with a few spleen cells here and there amongst 
them. The follicles were enlarged, and consisted mostly of leucocytes. In sections 
from the periphery, the cells often seemed to be arranged in cords along fine bands 
of connective tissue. The space between the cords was packed with red blood cells 
and phagocytes. Nearly all sections showed large numbers of hyaline cells containing 
red corpuscles and pigment. The more chronic the case the more blood pigment was 
found in the spleen, so that in all old cases the whole of the organ was filled with 
large granules, of which a fair number were intracellular. In some sections 
eosinophile cells were present in large numbers. There were also more or less 
extensive haemorrhages, the large ones destroying the tissue right up to the capsule, 
thus accounting for the ruptured spleen sometimes found. The vessels showed great 
proliferation of their endothelium, so that in places they seemed to be obstructed. 
The lymphatic glands presented marked changes. Very often the lymphoid tissue 
was reduced to small cords traversing the gland. Beneath the capsule was a small 
layer of lymphocytes. The spaces between the bands of lymphoid tissue network 
contained a few lymphocytes, hyaline cells with two or more nuclei, cells with a 
large quantity of included pigment, giving the iron reaction, and very many large 
free pigment granules (see Fig. i i). 
It is remarkable that in some cases in which the spleen contained only traces of 
pigment the lymph glands were practically filled with it. The amount of pigmenta- 
tion in the glands and spleen increases with the duration of infection. 
