1.Hematologic studies on 20 cases of natural cutaneous leishmaniasis, and two cases of artificially induced cutaneous leishmaniasis showed no changes in the blood picture. The formol gel test of Napier and Sia precipitation test were negative.
2.Four general paretics, who previously had cutaneous leishmaniasis, were injected intravenously with living leptomonas cultures of L. tropica in doses of 9,750,000 to 100,000,000. All four developed fever of about 40°C., lasting for three days. One general paretic, probably non-immune to L. tropica, was injected intravenously with 200,000,000 living leptomonas. He developed a chill, fever of 40.7°C., hepato- and splenomegaly, and obstructive jaundice. The symptoms subsided in about ten days.
3.All these five patients showed amelioration and improvement of their mental symptoms.
4.The writer was not able to produce kala azar in two patients who were presumably immune to cutaneous leishmaniasis.
5.South American leishmaniasis could not be produced in a patient who was presumably immune to cutaneous leishmaniasis.
6.A trial treatment with cultures of L. tropica may be given to general paretics, with the expectation of ameliorating the mental symptoms.