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       (2) It is not due to malaria. This has been proved in Section I of the
present report.

       (3) It is invariably associated with the presence of the Leishman-Donovan
parasite in the spleen and some other organs of the body.

       (4) I failed to find this parasite in the splenic and finger blood of forty-eight
cases of the disease I have described under the term " malarial cachexia," the
signs and symptoms of which are very different from those of kala azar.

       (5) The recovery of patients suffering from kala azar is coincident with
the disappearance of the parasite from their spleens ( ? and from other organs).
This was well illustrated in the patient named Godhala (case 15), and we may
assume that it was exemplified also in the patient named Mohan (case 38).

       (6) The parasite is present in parts of Assam where kala azar is prevalent,
and apparently it is absent from parts where this disease is unknown (e.g., the
Golaghat district: pages 28 to 30).

       This group of facts affords evidence sufficient, one would imagine, to justify
the belief that the Leishman-Donovan parasite is the cause of kala azar: but
the proof is not complete, any more than was the proof of the causal relation-
ship of the malaria parasite to malarial fever until the developmental cycle of
the parasite in the mosquito was established and the experimental infection of
man by the bite of this insect effected. And, in the absence of the conclusive
proof afforded by the experimental production of kala azar, there are certain
facts which require explanation before all doubt that the Leishman-Donovan
parasite is the cause of the disease can be removed from our minds. Perhaps the
most important of these is the presence of the parasite (or of one which in
appearance is indistinguishable from it) in the disease known as Oriental or Delhi
Sore. In a previous memoir* I have drawn attention to the following facts :
(1) a parasite indistinguishable from the Leishman-Donovan parasite is present in
the great majority of ulcers known in India as Oriental or Delhi Sores; (2) the
sores and the parasites in them occur in the Punjab where I was unable to find a
single case of kala azar; (3) kala azar and the parasites found in it occur in
Assam where I was unable to find a single case of Oriental Sore. Now, if the
parasite found in Oriental Sore is identical with that found in kala azar, it will be
obvious from these results that two conclusions are justifiable: one is that some
other factor than the mere presence of the parasite in a district is necessary for the
production of kala azar, the other that something more than the presence of the
parasite in the tissues of the skin is necessary for the production of this disease.

       Again, if the parasites found in Oriental Sore and in kala azar are identical,
there is, secondly, the fact that in most cases of Oriental Sore, even though
the number of parasites present in the sores may be very great, fever is absent.

     * Oriental or Delhi Sore: Scientific Memoirs by Officers of the Medical and Sanitary Departments
of the Government of India, New Series, No. 13.

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