present six days later. The same authors may have actually 

 transmitted Leishmania to man by bite of the sand fly one year later. 

 They fed experimentally infected P. sergenti Parrot on a number of 

 volunteers and obtained a positive lesion on the arm of one man. It 

 should be noted that the incubation period was so long that the 

 individual had visited endemic areas of oriental sore before 

 appearance of the lesion and therefore could possibly have acquired 

 the infection there (Adler and Theodor, 1929). Finally, 20 years 

 after Sergent and colleaques artificially transmitted oriental sore by 

 scarification, Adler and Ber (1941) proved without question that 

 artificially infected P_. papatasi can transmit oriental sore to a 

 human by bite. The key to this success appears to have been in 

 feeding the sand flies on flagellates suspended in three parts 2.7 

 percent saline and one part defibrinated blood. 



Leishmania donovani (visceral leishmaniasis, "kala-azar"). In 

 1915 Mackie, convinced that a relationship existed between kala-azar 

 and some biting insect, attempted to make a hut to hut insect census 

 in kala-azar-infected villages. His team collected body lice, head 

 lice, bed bugs, mosquitoes, sand flies and even leeches in the bedding 

 or on the persons of patients who were proven to have active kala- 

 azar; these specimens were carefully examined for Leishmania 

 parasites. All specimens were negative except the sand flies which 

 contained " Herpetomonas parasites" (probably Leishmania ), "bodo-like 

 parasites," and "sporozoan-1 ike parasites." Not realizing how close 

 he must have been to linking sand flies with kala-azar, Mackie stated: 

 "This long series of negative results rather tends to check enthusiasm 

 for the insect-borne hypothesis of kala-azar. . . . The only insect 



