ECOLOGY 35 



to consume an excessive amount of food or to feed on the tissue cells 

 of the host gut, they became the true endoparasites. Destroying or 

 penetrating through the intestinal wall, they became first established 

 in the body or organ cavities and then invaded tissues, cells or even 

 nuclei, thus developing into pathogenic Protozoa. The endoparasites 

 developing in invertebrates which feed upon the blood of vertebrates 

 as source of food supply, will have opportunities to establish them- 

 selves in the higher animals. 



Hyperparasitism. Certain parasitic Protozoa have been found to 

 parasitize other protozoan or metazoan parasites. This association is 

 named hyperparasitism. The microsporidian Nosema notabilis (p. 

 672) is an exclusive parasite of the myxosporidian Sphaerospora 

 polymorpha, which is a very common inhabitant of the urinary blad- 

 der of the toad fish along the Atlantic and Gulf coasts. A heavy in- 

 fection of the microsporidian results in the degeneration and death 

 of the host myxosporidian trophozoite (Kudo, 1944). Thus Nosema 

 notabilis is a hyperparasite. Organisms living on and in Protozoa 

 (Duboscq and Grasse, 1927, 1929; Georgevitch, 1936; Grasse, 1936; 

 Kirby, 1932, 1938, 1941, 1941a, 1942, 1942a, 1942b, 1944, 1946) 



References 



Bland, P. B., Goldstein, L., Wenrich, D. H. and Weiner, Elea- 

 nor: (1932) Studies on the biology of Trichomonas vaginalis. 

 Am. J. Hyg., 56:492. 



Chalkley, H. W. : (1930) Resistance of Paramecium to heat as af- 

 fected by changes in hydrogen-ion concentration and in inor- 

 ganic salt balance in surrounding medium. U. S. Pub. Health, 

 Rep., 45:481. 



Chambers, R. and Hale, H. P.: (1932) The formation of ice in pro- 

 toplasm. Proc. Roy. Soc. London, Ser. B, 110:336. 



Cleveland, L. R. : (1924) The physiological and symbiotic relation- 

 ships between the intestinal protozoa of termites and their host, 

 with special reference to Reticulitermes flavipes Kollar. Biol. 

 Bull., 46:177. 

 (1925) The effects of oxygenation and starvation on the sym- 

 biosis between the termite, Termopsis, and its intestinal flagel- 

 lates. Ibid., 48:309. 



— (1926) Symbiosis among animals with special reference to 

 termites and their intestinal flagellates. Gen. Rev. Biol., 1:51. 



— (1928) Tritrichomonas fecalis nov. sp. of man, etc. Amer. J. 

 Hyg., 8:232. 



(1949) Hormone-induced sexual cycles of flagellates. I. Jour. 



Morph., 85:197. 



- (1950) II. Ibid., 86:185. 



- (1950a) III. Ibid., 86:215. 



- (1950b) IV. Ibid, 87:317. 

 — (1950c) V. Ibid, 87:349. 



