364 AQUATIC PHYCOMYCETES 



SACCOMYCES Serbinow 



Scripta Bot. Horti Univ. Imper. Petro., 24: 162. 1907 



(Fig. 21 F-G, p. 360) 



Thallus epi- and endobiotic, monocentric, eucarpic, consisting of 

 the epibiotic rudiment of the prosporangium formed from the body of 

 the encysted zoospore and the endobiotic vegetative system, which is 

 often apophysate and broadly lobed, digitate, or saccate; prosporangium 

 epibiotic, sessile; sporangium inoperculate, subapical or lateral, very 

 thin-walled, ellipsoidal or long-tubular, bursting apart at maturity; 

 zoospores posteriorly uniflagellate, with a single globule; resting spore 

 asexually formed, borne like the sporangium, germination not observed. 



On Euglenophyceae. 



In its method of zoospore formation Saccomyces bears a resemblance 

 to Polyphagia. The character and development of the endobiotic 

 vegetative system, which occupies only one host cell, distinguish it, 

 however, from that genus. 



Saccomyces endogenus (Nowak.) Sparrow 



Aquatic Phycomycetes, p. 246. 1943 



Polyphagus endogenus Nowakowski, Akad. umiejetnosci Krakowie. Wyd- 

 ziat mat.-przyrod., Pamietnik, 4:191, pi. 10, figs. 108-114. 1878. 



Saccomyces dangeardii Serbinow, Scripta Bot. Horti Univ. Imper. Petro., 

 24: 162, pi. 6, figs. 22-33. 1907. 



Prosporangium pyriform, about 5 \x high by 3 [j. in diameter (cal- 

 culated), with a pronounced apiculus, wall thin, smooth, colorless; 

 sporangium broadly ellipsoidal or elongate-tubular, occasionally 

 branched, 1 5-30 u. long by 8- 10 \x in diameter, wall delicate, evanescent ; 

 endobiotic part consisting of a subsporangial apophysis (occasionally 

 absent), from the base of which protrude Irom two to four very broad 

 distally swollen digitations; zoospores nearly spherical, 2 \x in diameter, 

 with a colorless centric or eccentric globule and a long flagellum, 

 escaping upon the bursting of the sporangium wall; resting spore 

 spherical, about 10 \± in diameter, with a thick wall, the outer surface 

 covered by coarse conical spines, germination not observed. 



