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XI] The surface of a non-ulcerating sore is first painted with iodine and then punctured with a fine syringe. The parasites, as in the case of L. donovani, grow best in the ondensation water. Inoculation of cultures has given rise to lesions in monkeys. In what way, under natural conditions, the parasite enters the tissues it is as yet impossible to state definitely. Not improbably it is conveyed by flies or other biting insects, and by them either inserted into the skin or applied to some pre-existing wound or sore. Dogs in Teheran, and perhaps camels, are subject to this or a similar disease. Monkeys and dogs have proved to be experimentally inoculable, while donkeys, horses, goats, and sheep are refractory. It must not be overlooked that in susceptible animals an important source of infection may lie.

Probably there are two methods of infection (a) direct, the Leishman body being directly inoculated without undergoing sexual or other developmental change; (b) indirect, in which an infected fly, bug, or other insect, either itself or through its progeny, conveys to the new host the parasite which in the meantime has undergone evolutionary changes.* Wenyon has proved that the parasite is unable to enter through the unbroken skin.

As a rule, second attacks do not occur. Observing this, the Jews of Bagdad at one time practised on their young children oriental-sore inoculation.

Neither race, nor sex, nor age, nor occupation, nor social condition materially influences susceptibility. Incubation period and constitutional symptoms.—— The incubation period of oriental sore is variously stated in days, weeks, or months. That it may be a brief one, a few days or weeks, seems to be established by the appearance of the sore within a short time of arrival in endemic districts, or after