INSECTS AND OTHER ORGANISMS 411 



poison-germ," the great missionary-explorer had actually 

 in mind a microscopic organism, but his language suggests 



Fig. 84. — Parasitic Protozoa of Insects, a. Epithelium of stomach of 

 Honey Bee infected with Nosema apis : n, nucleus of epithelial cell ; p, 

 Nosema (feeding-stage) ; sp, spores of Nosema. X 700. b. Portion of 

 crop (" stomach ") of Mosquito (Anopheles) with cysts of malarial parasite 

 (Plasmodium) containing sporoblasts (St) or developed sporozoites (Tr) 

 (m, muscle bands). X 700. After Nuttall (Jo wrn. i^)-^. 1 901). c, Lepto- 

 monas scatophagae from fly Scatophaga stercoraria, X 1750. After J. S. 

 Dunkerly (Proc. R. Irish. Acad, xxxi, 1913). d, Trichomonas termitis from 

 Archotermopsis. X 1500. After A. D. Imms (Phil. Trans. R. S. 1919. 

 ccix). e, Trypanoso?na gambiense the " sleeping-sickness " parasite, 

 X 1500 (n, nucleus ; k, kinetonucleus ; /, flagellum ; m, membrane). 



that conclusion, and more than forty years later D. S. Bruce 

 (1895) described the flagellate protozoan (a species of 



