580 
Proceedings of the Royal Society of Edinburgh. [Sess. 
Lungs. — Here and there at the bases, foci of congestion show desquama- 
tion of the alveolar epithelium and collections of extravasated red cells 
and fibrin filaments within the alveoli. 
Alimentary Canal . — In some situations, particularly in the duodenum, 
extravasations of red cells are to be found, limited to the mucous membrane 
immediately below the glandular layer, and to the submucosa ; in other 
spots, denudation of the surface epithelium and small - celled infiltra- 
tion at the base of the ulcer formed by the destruction of the mucous cells. 
In still other areas, marked proliferation of the cellular elements may 
be observed. 
Liver. — The capillaries are dilated with red cells, very few polymorpho- 
nuclear leucocytes being visible ; and small - celled infiltrations may 
occasionally be noted around the perihepatic vein. Numerous intracellular 
capillaries are obvious throughout the sections. No changes are apparent 
in the hepatic cells themselves, though occasionally the hepatic trabeculae 
seem to be attenuated. 
Spleen. — Arteries, capillaries, and venous sinuses are dilated and filled 
with red- blood cells. In acute cases the splenic pulp is crowded with red 
cells, but in cases of long duration there is considerable increase of lymphoid 
tissue and of Malpighian corpuscles. The elastic fibres and reticulum are 
normal. 
Kidney . — Hyperaemia is the chief change noted in this organ : the loops 
of the glomeruli are distended with blood ; the interlobular arteries and 
vasa erecta are also dilated. No thickening of the capsule and no change 
in the epithelium of either tubules or glomeruli can be made out. 
Mesenteric glands are enlarged, not so much by reason of hyperplasia of 
the follicles and trabeculae, as by hyperaemia, as is shown by the dilatation 
of the sinuses, which are filled with blood cells. The follicles are not, as a 
rule, particularly rich in lymphocytes. 
Bone-marrow. — In chronic infections this tissue shows marked altera- 
tions from the normal in its constitution. Nucleated red cells and lymphoid 
cells, that is, giant cells, mononuclear cells, and lymphocytes, are markedly 
increased in number ; granular cells, i.e. myelocytes and polymorphonuclear 
leucocytes, are considerably diminished : the whole forming a typical lympho- 
erythroblastic bone-marrow, and is in marked contrast to the leucoblastic 
marrows associated with, for instance, pneumococcic infections. 
Blood . — During the early stages of M. melitensis infection the micro- 
coccus can be detected in the peripheral blood by cultural methods, but 
microscopical examination of the blood direct usually, except in the very 
acute and severe infections, fails to demonstrate its presence. In man the 
