Vol. XXIV] ENTOMOLOGICAL NEWS. 173 



the necessary equipment for bacteriological work and the skill 

 he may keep artificial cultures by the method first perfected by 

 MacNeal and Novy, '03. 



It should not be forgotten that the first trypanosome de- 

 scribed and the type of the genus was found by Gruby, in 

 1843, m the blood of the frog. This, or a very closely related 

 species, is not rare in frogs in this country, and on account of 

 its comparatively enormous size is a striking object for demon- 

 stration. Other species arc to be met with in the blood of 

 fishes and reptiles. 



Closely related to the Trypanosomes are certain flagellated 

 parasites of the alimentary canal of insects. The most common 

 of these are CritJiidia mclophagia, which is found in practically 

 all sheep ticks, and Herpetomonas muscac domesticae which is 

 very common in the house-fly. It is claimed by some that the 

 first of these is a stage in the development of a blood parasite 

 of the sheep. Whether that is true or not both forms are of 

 interest as parasitic protozoa of insects. 



The complicated life-cycle of the malarial parasite is not 

 readily comprehended by a student who has had no training in 

 protozoology and hence I find it very helpful to introduce this 

 subject by the study of a comparatively simple sporozoon, and 

 by the examination of some of the larger haemosporidia. 



The most satisfactory and readily available form for intro- 

 ductory work is a species of Monocystis from the seminal 

 vesicles of the earthworm. Practically every worm is infested, 

 though the larger ones are more easily examined by beginning 

 students. I have never failed to find during a practicum the 

 immature trophozoites within the sperm morulae, motile tro- 

 phozoites, encysted gametocytes, cysts, spores and mature 

 sporozoites. 



Of the Haemogregarinidae, one of the first discovered was 

 / .(inkestcrclla ranarum (better known as Drepanidiwm ninar- 

 um), which was found by Lankester in 1872. This is fairly 

 common in frogs at Ithaca and in those which I have had from 

 North Carolina and from Wisconsin. While the life cycle of 

 this species is not understood, Durham, '02, believes that the 



