64 CASPER 0. MILLER. 



gellura, and when they do change their shape the pseudopodia 

 are naore rounded. 



The zoospores of plasmodia usually have a single flagellum, 

 but they may have two or four. The writer has not seen 

 zoospores of the Endosporia with more than one nucleus, 

 whereas large zoospores of Cerat. porioides have occa- 

 sionally been found which have two distinct nuclei (fig. 12, /.). 



In all species of plasmodia which the writer has examined, 

 one can distinguish two forms of microcysts in the cultures. 

 In the simple form the cyst wall is made up of a single homo- 

 geneous membrane, closely applied to the protoplasm, as indi- 

 cated in fig. 12, m. In the second form the cyst wall is made 

 up of an outer thick membrane, irregular or scalloped in 

 outline, and an inner, thinner membrane, which is closely 

 applied to the protoplasm (see fig. 12, n., o.). One finds cysts 

 intermediate between these two varieties. The simple micro- 

 cysts ofStemonitisA measure 5 — 7 fx in diameter, the thick- 

 walled cysts measure 10 — 14 p. in diameter. 



In cultures of Stemonitis A, B, and C, and Phys. cin- 

 ereum made in hay infusion, the thin-walled microcysts 

 remain unstained, whereas the membrane of the thick-walled 

 cysts may be stained a brownish colour. 



In old cultures made in hay infusion at times one sees 

 microcysts with dark brownish, almost black pigmented 

 granules in their interior. 



Lister (44) speaks of the spores of Ceratiomyxa as having 

 four '' nucleus-like " bodies, and pictures them indistinctly in 

 his plates. The writer's observations show, from staining with 

 picro-carmine, that these bodies are true nuclei. 



Famintzin and Woronin (10) showed that after the proto- 

 plasm escaped from the spores of Ceratium it remains at one 

 place for some time, undergoing amoeboid changes. It then 

 divides into four round segments, each of which divides and 

 gives origin to two zoospores. Lister (44) describes the 

 naked spore dividing into eight spherical segments which re- 

 main attached to each other. These develop flagella, and then 

 separate. 



