86 THOMPSON YATES AND JOHNSTON LABORATORIES REPORT 
organs showed lesions which varied with the intensity and duration of the infection. 
The heart often showed all the signs of a haematogenous myo- and epi-carditis. The 
lungs were often highly congested ; the parietal and visceral pleura had often small 
haemorrhages. In every case there was great congestion of the liver vessels. Thev 
contained a large number of leucocytes. There was proliferation of their endothelium, 
and they were often surrounded by small-celled infiltration. The liver cells 
showed fatty infiltration, and, at a later stage, fatty degeneration. Far advanced 
parenchymatous degeneration was frequently found. The kidneys did not show 
anything of note, except great congestion of the vessels and smaller and larger 
haemorrhages between the tubules. 
The spleen, however, showed great changes. In almost all animals it was more 
or less enlarged, sometimes up to thrice its normal size. It was generally of a dark 
purple-red colour, and had a tense capsule. In cases dying after an acute course of 
infection its pulp was very soft, and the follicles large and very prominent. Micro- 
scopically, the hyperaemia was striking, being more pronounced at the periphery than 
towards the centre. In some cases small necrotic areas were present. 
The spleen cells generally took the stain deeply. The follicles were hyper- 
plastic and irregularly defined, with processes running out from them. They 
may be described as follows : — a centre of lightly-stained cells having the appearance 
of granulation cells, around it a dense layer of lymphocytes with numerous red blood 
corpuscles interspersed. The vessels running in the trabeculae showed proliferation 
of their endothelium. There were a large number of phagocytes with included red 
cells and here and there were leucocytes with eosinophile granules. The red blood 
corpuscles accumulated in the spleen often showed all the signs of degeneration. 
Blood pigment, giving the iron reaction, was also present, both intracellular and free. 
The spleen of those animals which had died after a more chronic infection was 
in the majority of cases much enlarged, dark, and of firm consistence. The 
malpighian bodies, however, were not so prominent, but rather seemed to be lessened 
in number and in size. On microscopic examination, the trabecular system showed 
much hyperplasia. The whole organ was very hyperaemic, many of the blood cells 
showing degeneration. The phagocytes and leucocytes with eosinophile granules 
were increased in number. Some cases had a large amount of blood pigment. 
The lymphatic glands were usually enlarged, and their stroma hyperplastic. In nearly 
all the groups besides glands of normal aspect there were others reddish-brown or dark- 
brown in colour, which presented intersections of greyish bands corresponding to the 
hyperplastic connective tissue. On microscopical examination they showed sinus 
formation throughout the gland. The sinus contained many red and white blood 
corpuscles, phagocytes, which had included pigment, and the granular remains of red 
blood corpuscles. The lymphoid tissue often had many free blood corpuscles inter- 
spersed through it, along with a varying number of eosinophile cells, pigment, and 
