6

       Distribution of the parasite.—Bodies were very abundant in the liver and
spleen. The bone-marrow was not examined. In both ulcers single bodies were
seen lying in the organised granulation tissue in the bases and also in the healthy
tissues beyond. Large cells crowded with the bodies were seen here and there
in the small vessels in the neighbourhood of the ulcers.

       GENERAL POST-MORTEM APPEARANCES.—It will be seen from the seven
autopsies now described that there are certain constant pathological appearances
associated with infection by the new parasite. We may summarise these as
follows.

       The post-mortem appearances of the liver and spleen are in themselves
almost pathognomonic. The spleen has a peculiar smooth, firm and solid look,
and it retains its shape after removal from the body like an organ hardened in
situ. The substance is dark red, granular and homogeneous. The trabeculæ
shew up clearly against the dark pulp. The consistence is firm but friable and
the sensation given to the finger is quite different to that given by a tough fibroid
spleen. The liver retains its shape after removal. The liver substance is firm but
friable. The surface is mottled, suggesting the nutmeg liver of passive engorge-
ment, but the general colour is lighter instead of darker than normal. On section,
the mottled look is seen to be due to a white tissue which occupies the centre of
the lobules and gives rise to an arborescent appearance. Microscopical examina-
tion shews that the white tissue is a new deposit formed of macrophages and their
contained bodies, which have practically replaced the liver tissue of the centre of
the lobule.

       The large intestine shews, almost constantly, extensive multiple ulcers which
are deep and sloughy and tend to perforate the muscular coats. The occurrence
of fungating granulation tissue which has a papillomatous appearance is seen in
association with the ulcers.

       Purulent peritonitis and bronchopneumonia are frequent, arising, respectively,
from the perforation of intestinal ulcers and as a sequel to cancrum oris.

       Septic conditions associated with the formation of infarcts in the organs are
sometimes superadded.

       The small intestine rarely shews any lesions. The heart, kidneys, brain,
gall-bladder, urinary bladder, pancreas, suprarenals, testicles, lymphatic glands and
muscles shew, as a rule, no macroscopic changes.

       The parasites are found constantly in immense numbers in the cells of the
liver, spleen and bone-marrow, in granulation tissue in the intestine and in the skin.
They were present in large numbers in a lymphatic gland draining an area in
which a skin lesion was present, but not in glands where no such condition existed.
Bodies are, in some cases at least, fairly numerous in patches in the testicle.
In the kidneys they do not appear to be numerous. They are present in some