35: 



FAMILY: TRYPANOSOMID^ 



Franchini (1913a) that they were able to infect mice. These experiments- 

 will be considered more fully below. The presence of L. ctenocephali in 

 fleas led Basile and others to the view that Leishmania donovani undergoes 

 a development in the flea, the natural flea flagellate being mistaken for 

 developmental forms of the parasite of kala-azar. 



As will be seen in the lists of hosts, leptomonas have been found in a 

 number of fleas, and some of these have been given specific names without 



Fig. 164. — Lejytomonas ctenocepliali from Intestines of Dog Flea {Ctenocephahis 

 canis) {x 2,000). (Original.) 



At bottom right-hand comer are the presumably encysted forms which occur in faeces. 



there being any real justification for this procedure. The form in the human 

 flea, Pulex irritans, was studied by the writer (1912c), and was named L. 

 pulicis by Patton and Eao (1921). They found fleas naturally infected, and 

 also succeeded in infecting fleas experimentally by feeding them on cultures 

 of the flagellate. Larvae kept with infected fleas became themselves in- 

 fected. They ingest the rounded forms passed in the faeces of the adult, 

 and acquire an infection of the stomach in which the flagellates live and 



