Observations on leptomonas ctenocephali (Fantham, 1912)

Abstract

1. The developmental cycle of Leptomonas ctenocephali in the larval and adult stages of the dog flea, Ctenocephalus canis, is described. 2. Resistant forms of the parasite are contained in the dried faeces of infected fleas, and these, when ingested by larvae, flagellate and multiply in flagellate form in the mid-gut. 3. In the adult flea the infection is confined to the bind-gut, rectum and occasionally the Malpighian tubules. The forms found are leptomonad, leishmania-like and smaller leishmanial resistant bodies. 4. The resistant bodies develop in saline after a period of 2 months in dried faecal blood. When artificially removed from the flea by dissection they develop in saline after being dried for not longer than about 5 hours. 5. The development of the resistant body into a long, highly motile leptomonad takes places within about hours in saline. 6. Experiments regarding the survival of the resistant bodies under adverse conditions are described.