E.rprriinenfs mi the development of Leishmniiia tropica /h- 

 (Hill ex Ipctularius. 



Tlie OTitlioi produced in liimself Oriental sore by inoculation in 

 Aleppo in August, 1911. Six and a half months later 3 sores 

 (non-ulcerating') appeared. Of 105 bugs, bred in tbe laboratory 

 and allowed to teed on tbe thin red epidermis over the sore, only 

 8 gave positive results. Tliese were dissected only 2 or 3 days 

 after feeding ; the others 4-1) days after. The author regards 

 tlie results as practically i)r()virig that no active multiplication of 

 the parasite took place. 



The flagellates found resembled those of artificial cultures and 

 the author is of oi)inion that the failure to develop beyond a 

 certain point was due to failure of nutriment; as in exhausted 

 culture media round or non-flagellate forms are found, so in the 

 bug they appear when the blood is nearing the completion of 

 digestion. 



E.i'/xtI nieiifs cnndiirfeil iriih Fleas. 



The author describes in detail Nrdler's jnethod of handling and 

 feeding fleas for experimental purposes and then gives an account 

 of tlie results of liis own experiments. 



Fleas which yielded negative results when fed upon uninfected 

 persons were fed on the author's own sore and then found to pass 

 free parasites in their faeces. All possibility of confusion with 

 any Herpefomonas of the flea itself would thus appear to be 

 removed. As the result of a number of careful experiments with 

 CtenocephaJus catii< (the dog flea) and J^ide.r in-ifans the author 

 arrived at the following conclusions: — 



1. That the dog and human fleas, Cfenorepludvs ranis and 

 Piile.r irritans, readily take up Leislnnaiiia tropica from the sore 

 and that some of them are passed in the faeces voided during the 

 act of feeding. 



2. That if a flea is infected with flagellates the faeces voided 

 during the feed will contain some of these. 



3. That the Lei.diviania taken up do not develop into flagellate 

 forms or produce an infection of the flea's gut. 



4. The fleas that have not become infected with Leish mania 

 maybe infected with Try pan 0x0)11 a leinsi. 



b. When once infected with Herpetonionas or T. leuusi the fleas 

 remain so infected for long periods whether they feed upon human 

 or rat's blood. The human blood appears to be quite favourable 

 to the develo])ment of T . leiri.si in the flea. 



(). T. leirisi ai)])cars to undergo its development in Piile.r 

 irritans as well as in the dog-flea, CtenoceplKdus cams. 



7. As Noller has shown, it is the faeces passed by the flea 

 which, when licked uj) by the rat, ])roduce an infection. The act 

 of feeding itself apparently does not infect. This has been con- 

 firmed by feeding the dog-flea on a T. lewisi rat, feeding it sub- 

 sequently on a second rat, and giving the faeces passed during the 

 feed to a third lat. It is only the third rat that becomes infected. 

 The incubation period was six days in the rat. 



