ANIMAL PARASITES 67 



flagellum arising from a composite kinetoplast, which in those 

 genera, lies anterior to the nucleus. 



These will be illustrated by the widely distributed Herpe- 

 tomonas muscce-domesticce from the intestine of house flies and 

 related species. It is transmitted from fly to fly in the form of 

 cysts in the feces. A much-studied Leptomonas is found in 

 fleas, while the genus Crithidia, characterized by a rudimentary 

 undulating membrane, is readily obtained from the intestine of 

 the aquatic bugs commonly known as " water-striders." 



References 



Excellent discussions of the trypanosomes and related flagellates are to 

 be found in the texts of Craig; Hegner and Taliaferro; Hegner, Augustine, 

 and Root; Thompson and Robertson; and especially of Wenyon. The 

 following references indicate some of the sources of material for study. 

 Becker, E. R., 1923. Observations on the morphology and life cycle of 



Crithidia gerridis Patton in the water-st rider, Gerris remigis Saw 



Jour. Parasitology, 9: 141-152. 

 Beckek, E. R., 1923 b. Observations on the morphology and life-history 



of Herpetomonas musca;-domesticoe in North American muscoid flies. 



Jour. Parasitology, 9: 199-213. 

 Crawley, H., 1912. Trypanosoma americanum, a common blood parasite. 



of American cattle. U. S. Dept. Agr., Bu. An. hid., Bull. 145: 5-39. 

 Drbohlav, J. J., 1925. Studies on the relation of insect flagellates to 



leishmaniasis. Am. Jour. Hyg., 5 (5): 580-621. 

 Hegner, R. W., 1921. Measurements of Trypanosoma diemyctyli from 



different hosts and their relation to specific identification, heredity, and 



environment. Jour. Parasitology, 7: 105-113. 

 Hoare, C. A., 1923. An experimental study of the sheep trypanosome 



(T. melophagium Flu 1908) and its transmission by the sheep ked 



(Melophagus ovinus L.). Parasitology, 15: 365-424. 

 Minchin, E. A., and J. D. Thompson, 1915. The rat trypanosome, 



Trypanosoma lewisi, in its relation to the rat flea, Ceratophyllus fasciatus. 



Quart. Jour. Micro. Sci., 60: 463-692. 



