PARASITES OF PROTOZOA 1057 



The spores are very much Hke those of Sphaerita. Their shape is 

 spheroidal or eUipsoidal, and the wall stains more intensely than the 

 contents. Some show a thickening at one side, in crescentic form (Ep- 

 stein, 1922; Brumpt and Lavier, 1935a; Lavier, 1935b). In the interior, 

 often no structure is discernible, or one or two granules are seen, or a 

 central nucleus may be observed. Dangeard (1895) and Epstein (1922) 

 reported a vesicular nucleus; Brumpt and Lavier, however, failed to 

 observe a definite nucleus in the parasite of Endolimax nana, studied 

 by Epstein. In Nucleophaga of Caduceia theobromae, a spheroidal gran- 

 ule of relatively large size was observed toward one end of the spore 

 (Fig. 218M). This may be a nucleus. In size, the spores range from 

 one to 2 p, some being reported as only about one \x (Brumpt and 

 Lavier, 1935a), some 2 |j (Lavier, 1935b; Penard, 1905b), others as 

 having a variability from about one ^ to 2 p (Mercier, 1910; Mattes, 

 1924). 



No flagella have been observed on spores of Nucleophaga, with the 

 possible exception of those mentioned in the account by Robertson 

 (1905). She described what she supposed to be gametogenesis of 

 Pseudospora volvoch, in a rather complete account of what is probably 

 the development of Nucleophaga. The "gametes," as figured and de- 

 scribed, are each provided with one flagellum; and they are reported to 

 fuse, producing a biflagellate zygote. 



EFFECT ON HOST 



Minden (1915) wrote (translation): 



In the lower plants, mainly algae, which in the widest variety are sought by 

 parasitic Chytridiales, the injuries are usually so striking that these fungi 

 are designated as dangerous parasites of algae. In a short time large cultures 

 of diatoms, flagellates, and other unicellular organisms may be completely 

 destroyed; but also filamentous algae die cell by cell. The first indication of 

 injury is in the discoloration and disorganization of the cell contents . . . 

 finally there remain only granular vestiges. 



Infection with Sphaerita may be observed in many Protozoa that 

 appear entirely normal, but it often ends fatally. The host may some- 

 times rid itself of the parasite and continue normal life (Dangeard, 

 1895; Penard, 1912); on the other hand, many observers report death 

 of the host at the time of sporulation. 



