46
canal. The stomach generally presents extensive ulceration, but its pathological
condition has been already noted in detail (Parts I and II). The alimentary and
respiratory mucous membranes are elsewhere and in other respects free from disease with
the exception of the ulcers alluded to in our notice of symptoms. These ulcers seem
only to occur on those parts of the mucous membranes which are visible in the living
animal, and they resemble those of the stomach in being atrophic degenerations ; they
are, however, evanescent, less frequent, and less numerous. The spleen is, I find, almost
always enlarged and generally weighs about 4 lb. Its structure is not frequently
disorganized, although in some instances there are circumscribed blood accumulations
in it and on its surface. Generally there is an excess of spleen pulp, so that it pits on
pressure and long retains the impression of the fingers. Microscopical examination of
the fresh pulp failed to demonstrate any abnormality although on one or two occasions
I have noticed an unusual preponderance of spherical highly refractive bodies generally
aggregated in pairs. The liver is usually quite healthy and not nearly so frequently
the seat of congestion at Rangoon as it seems to have been at Tonghoo. The kidneys
are seldom free-from disease; either they are in an anæmic, dropsical state, or else are
markedly congested. In one instance I noted a considerable amount of extravasation
on and in the under part of the right kidney as though some blood-vessel had given
way. Large clot's of the most varied colors may be drawn from the large vessels at
the upper part of the abdomen and the hind limb; even when the investigation is made
immediately after death, these are often found. The sublumbar muscles are normal;
the supralumbar will generally be found atrophied. The lungs are congested in most
cases, but once, where a clot prevented passage of blood to them, they were peculiarly-
dry and anæmic. The trachea is generally full of froth. The heart in chronic
cases has gelatinous accumulations in its furrows in place of fat and a few extravasa-
tions along the course of its blood-vessels; but in only one case have I seen any
beneath the endocardium, and then it was into the substance of an auriculo -ventricular
valve. In all advanced cases the heart is large and flabby as having undergone
extensive fatty degeneration; both sides are filled with blood with clots of various
colors; thus I have seen from the four orifices of the same heart severally and
respectively yellow, purple, bright red, and a greenish blue clot projecting. In all
the more prolonged cases the brain and spinal cord with their meninges are decidedly
sodden and anæmic; the brain is soft and looks as though it had been for some time in
water ; the plexus choroides of the lateral ventricles are bloodless and of a pale yellow
color. In acute cases there is sometimes very slight congestion, but I have never
seen this so pronounced or associated with the presence of blood-clots pressing on the
brain as seems to have been the case not infrequently at Tonghoo (vide Parts I and II).
8. With the discovery of minute organisms in the blood arose numerous and
important questions resembling those which have been so long and hotly debated
concerning the bacillus of anthrax. Firstly, is the spirilloid organism a feature of the
disease, or is it merely an accidental accompaniment ? My researches show that it is
found in all cases of the disease, is in direct and immediate association with a certain
phase of the disease; thus, when the temperature is about to rise, the spirilloids become
detectable, they become very numerous and active during the rise and the climax of the
fever, but disappear just before the crisis; thus its presence in spirilloid form seems
directly related to the degree of the fever, and its phenomena and activity seem to bear
definite relations to the severity of the relapse. The features of the life-history of the
organism, in so far as we are acquainted with it, place us in a position to attribute all
the disease conditions of the patient to it. The inoculation of an animal with blood
containing the parasites invariably produces the disease (except when the. inoculated
animal is a ruminant), but I have also proved that blood taken from an animal when
no organisms are detectable will likewise convey the disease, but less rapidly. We
have a strong chain of evidence that the parasite is the actual and immediate cause of
the disease, and further that it is itself the materies morbi. We infer that it acts in
two ways to produce the symptoms and fatal result; in its active phase it tears and
drags at the red corpuscles and causes their disintegration ; it passively acts by
blocking up the capillaries. Careful examination of the records of cases shows that
the occurrence of petechiæ on the mucous membrane especially takes place when the
parasites are not detectable in the blood by ordinary methods, i.e., from just before the
maximum of the curve to just before the commencement of the next rise. When the