NOTES ET REVUE xlv 



The free trophozoiles are roiighly ovoid in sliape. They are l'rom 

 23 ijL to 31 [x long and froin 11 [j- lo 15 a broad. The parasites are 

 nonseptate and so are monocyslid. They possess a culicle wliich 

 gives a definite contonr to the body, and a distinct ectoplasin and 

 endopLasm are visible. Tliis is vvell seen in transverse and slightly 

 oblique sections of the organisms. A large nucleus is présent. It lias 

 a complicated structure which needs careful considération. 



The ectoplasm is clear, hyaline and undifTerentiated except at the 

 anterior région. Hère it is prolonged forward lo i'orni an organ of 

 attachment, the epimerite. This is shaped like the head of a lance 

 and contains practically no endoplasui. From tlie epimerite to the 

 neighbourhood of the nuclear membrane the ectoplasm is marked 

 by a séries of fanlike, radiating, contractile éléments, the myonemes. 

 Thèse are limited in extent to the anterior région of the ectoplasm, 

 and in this respect (as well as in others), Merogregarina diflers 

 from the Selenidiidne, whose myonemes traverse the entire lengtli 

 of the body. 



The endoplasm is richly granular and the granules would seem lo 

 consist of reserve food materials, whicli are used in sporulation. 



The constitution of the nucleus is vesicular, and, as is the case 

 with most vesicular nuclei, there is an extremely well marked 

 nuclear membrane, which hasan internai, somewhatirregularlining 

 of chromatin. Within is a chromatin reliculum, and attached to 

 this, but lying usually to one side of the nucleus, is a large 

 karyosome. This stains deeply and is most obvions. Its shape varies 

 but is mostoften spherical or roughly dumb-bell shaped. 



One or more plasmosomes are frequently présent within the 

 nuclear sap. Thèse aggregations stain less deeply than the 

 karyosome and are of the nature of true nucleoli. 



Reproduction, as in ail Schizogregarines, shows both sexual and 

 asexual forms. 



The asexual multiplication or schizogony occurs within the gut 

 cellsof the host and so is intra-epithelial. Amerozoiteor a sporozoite 

 pénétrâtes either between or into an epithelial cell of the gut of the 

 host, occasionally leaving open its channel of entrance beliind it. 

 Once within the cell, a space forms round it, and in the cavity so 

 formed, in which several cells may be involved, the youngschizont 

 lives and grows. When it is about 17 ij- long and lO'o ii broad, its 

 nucleus begins to divide. This isinitiatedby the disappearanceof the 



