254 RESEARCH IN PROTOZOOLOGY 



tmiscce-douicstico', but he in turn gave no careful description. 

 Prowazek (1904), however, gave an accurate description of one of 

 the fly flagellates for which he retained the name H. muscce- 

 d oiliest icce. Therefore, should not this name be retained for the 

 species to which it was applied, despite the argument of Hoare 

 (1924) for H. muscarmn? If it should develop that only one 

 species of flagellate may be found in the "house-fly" (and it must 

 be remembered that seventy-five years ago a "house-fly" might be 

 any one of a number of species) there might be some argument 

 for this procedure. Since Leidy gave no morphological description 

 whatever of the flagellates he observed it seems doubtful if the 

 specific name niiiscarum need be retained at all. 



Any one who would desire to extend our general knowledge of 

 this group (trypanosomid.e of insects) would probably have 

 ample opportunity to describe new hosts and make studies of the 

 parasites. A specimen of Triatoma sangiiisuga, which occurs in 

 the southern part of the United States, was sent to the writer a 

 number of years ago. It was found to be heavily infected with a 

 Crithidia, or the crithidial stage of a trypanosome. How do flag- 

 ellates of flies "winter over" in our northern clime ? These and a 

 number of similar problems will confront workers investigating 

 insect flagellates. 



Under host-parasite relations we might discuss the problem of 

 the effect of the flagellates on the health of their host. It is gen- 

 erally assumed that the host is not injured in the least by an infec- 

 tion of these teeming myriads of flagellates. Recently, however, 

 Paillot (1927) has described a pathological flagellosis in the Euro- 

 pean corn borer (Pyransta niihilalis) caused by Lcptomonas 

 pyraustcE. If this is true it is important, and more work is needed 

 to either confirm or disprove this author's findings. 



INSECT FLAGELLATES OTHER THAN TRYPANOSOMID^ 



At the present time this group may not be so alluring to a pros- 

 pective investigator as the preceding one. This is probably because 

 not so much work of a fundamental nature has been done in this 

 group, and hence the trend of future experimental work is not so 

 well indicated. Comparatively few publications have appeared, and 

 the number of recorded hosts and entozoic flagellates is not large. 

 Among the more important papers are those by Mackinnon 

 (1910, 191 1 ) on flagellates of trichoptera and Tipula larvse cited 



