396 FAMILY: TRYPANOSOMID/E 



in the body cavity, whence all the organs of the body were invaded. He 

 (1921) succeeded in obtaining a culture of the organism L. pyrrJiocoris in 

 N.N.N, medium. In the same year (1921a) he investigated the effect of 

 these cultures on other arthropods by inoculating them in the body cavity. 

 He found that active multiplication occurred, some of the experimental 

 arthropods becoming overrun with flagellates. In this manner he suc- 

 ceeded in infecting Notonecta glauca (water boatman), Naucoris cunicoides 

 (aquatic bug), Galleria mellonella (caterpillar of bee-hive moth), CaUiphora 

 sp. (larva of blow-fly), Tenebrio molitor (larva of meal-worm). The most 

 intense infections were produced in the larva of the meal-worm and the 

 caterpillar. Glaser (1922) has similarly succeeded in infecting Melanoplus 

 femurrubrum (grasshopper) and Amblycorypha oblongifolia (locust) with 

 H. muscarum of the house fly. 



By feeding bed bugs on cultures of Leptotnonas pidicis, Crithidia cteno- 

 cephali, and Herpetomonas muscarum, Patton, La Frenais, and Eao (1921) 

 have shown, by making cultures from the intestine in N.N.N, medium 

 at varying intervals after feeding, that the flagellates can survive for 

 thirty-seven, eight, and forty-five days respectively. 



Genus: Leishmania Ross, 1903. 



The flagellates included in this genus are characterized by the possession 

 of both a vertebrate and an invertebrate host, as in members of the genus 

 Tryjjanosotna, from which they differ in that only leishmania and lepto- 

 monas forms occur in the cycle of development. In no case, how^ever, 

 has an invertebrate host actually been demonstrated, but the evidence 

 that such a host exists is so convincing that this feature has been included 

 in a definition of the genus. 



From the purely morphological point of view there are at present no 

 data which afford a means of distinguishing members of the genus Leish- 

 mania from those of the genus Leptomonas. In both there occur only the 

 leishmania and leptomonas forms. The members of the genus Leptomonas 

 are handed on from one invertebrate to another by the contaminative 

 method by means of encysted forms passed in the fseces. No such stages 

 are known in the case of Leishynania, though they may occur. It would 

 thus be quite logical to include Leishynania in the genus Leptomonas. 

 Nevertheless, on account of the existence of two hosts in the former and 

 a single one in the latter, the retention of the separate genera is a con- 

 venience. The inclusion of Leishmania in the genus Herpetomonas, as 

 Patton and others have done, cannot be admitted, as the members of the 

 genus Herpetomonas have definite trypanosome stages which do not occur 

 in Leishmania. 



The first observer to see one of the parasites which are now regarded 



