650 J. S. DUNKERLY. 



"wliicli are of any service are that Leptomonas was TrTr*,^^ in. 

 long, and formed rosettes, while Herpetomonas was g-^^- to 

 -^-^ in. long", and had, at any rate, not been seen in rosettes 

 or agglomerations. In 1902 Leger (9) found flMgellate 

 parasites in Homalomyia and other Diptera, and named an 

 elongated form Herpetomonas (sp. yar.), while a short 

 rounded form, " en form de grain d'orge," he called 

 Crithidia (sp. var.). Later (10, a and b), he described 

 H. subulata from Tabanus as possessing an undulating 

 membrane, still retaining the name Crithidia for shoi-t 

 pyriform forms. Prowazek (20) in 1904 liad investigated 

 the parasite of the house-fl}^, and described it as possessing 

 two flagella united by a membrane and arising from an 

 anterior double basal-granule or diplosome, Novy, MacNeal, 

 and Torrey, in 1907 (16) followed Leger's nomenclature for 

 types found in mosquitoes, their Herpetomonas in cultures 

 showing an undulating membrane. They described a diplo- 

 some, not where Prowazek had placed it, but at the jiosterior 

 end of the body, and bearing, as they themselves point out, 

 a considerable resemblance to a Diplococcus, which was 

 generally adherent to the body of Herpetomonas in the 

 cultures. Lingard and Jennings (12) in 1906 found in a 

 Muscid fly forms showing the typical di]Dlosome described by 

 Prowazek, but most of their figures are not clear, and they 

 claim to have seen the actual foldiug of the flagellate to 

 form the biflagellate condition according to the Prowazek- 

 Schaudinn theory respecting the origin of the doul)le 

 flagellum. 



The history of Herpetomonas up to this point has been 

 related in greater detail by Woodcock (25). His conclusions 

 are — (1) That some of these parasites of mosquitoes are 

 probably connected with Trypanosomes of vertebrates ; (2) 

 some of the typical Herpetomonads found may be simply and 

 primarily parasites of the insects ; (3) that forms adapted 

 for life in sanguivorous insects, by which are meant 

 "Crithidia" forms with an undulating membrane, following 

 P9,tton's nouipn^'lature, may be unrelated to any trypauosome 



