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undulating membrane and that the does not pass from the
anterior end towards the macro-nucleus. From this he concludes that the
parasite belongs to the order Herpetomonas and is not a true trypanosome,
naming it the Herpetomonas of Kala Azar. This conclusion seems to be prema-
ture, especially When it is Considered how little is yet known of the life-histories
of the different species of this genus (Herpetomonas) of the Flagellata.

   Before describing the experiments carried out with the various blood-
sucking insects, it is important to consider how the human body might be
primarily infected by the parasite, and, in order to answer this question, it is
necessary to examine the theories which have been advanced to explain the
channels by which the parasite leaves the human body.

   Sir Patrick Manson⁷ and Dr. Low, studying a case of Kala Azar in the;
Seamen's Hospital, London, were unable, after a prolonged search in films of
the finger blood, to find any of the parasites, and concluded. that the disease
could not be transmitted by means of the peripheral blood. As they found
the parasite in the liver as well as in the spleen, they thought it possible that the
biliary ducts were the channels by which the parasite escaped into the fæces.
They were, however, unable to find any parasites in this situation. On the
death of this patient, they⁸ examined sections of his organs and were able to
confirm Christophers' observation as to the presence of the parasites in the
ulcers of the large intestine; they suggest that the parasites may escape by the
intestinal tract.

   Captain Statham,⁹ R.A.M.C., has carried out a large series of examinations.
and cultural experiments with the fæces from a case of Kala Azar, and has
failed to find the parasite in this situation; and I have on many occasions
searched for parasites in the mucus in the fæces of cases of Kala Azar, also,
in the sanious discharge from cases with cancrum oris, but in neither case
have I ever found parasites. Captain Statham⁹ has also pointed out that he
was unable to recover the parasites from (1) sterile tap water, (2) sterile-
pond water and (3) ordinary pond water which were inoculated from splenic
cultures.

   Several observers have noticed that the Leishman-Donovan bodies readily
die out in a cultivation of splenic blood if it becomes bacterially contaminated,
and fæces of Kala Azar patients suffering from diarrhœa swarm with bacteria
of many kinds.

   The occurrence of the Leishman-Donovan bodies in ulcers of the skin has
led Sir Patrick Manson ¹⁰ to suggest that the parasite leaves the human body
in the discharges from ulcerated surfaces, intestinal or cutaneous, and is
ingested by some foul-feeding fly in which it undergoes multiplication, and is
then implanted into the human host by this insect by a bite or by contact with,
broken skin surface.

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