974 AQUATIC PHYCOMYCETES 



Sporangia forming an intricate complex, irregularly saclike, often 

 lobulate; fertilization pore formed; in rotifers 



M. zoophthorum, p. 979 

 Sporangia separate; in rotifers M. microsporum, p. 980 



Myzocytium proliferum Schenk 



Uber das Vorkommen contractiler Zellen im Pflanzenreiche, p. 10. 



Wurzburg, 1858 



(Fig. 79 A-C, p. 977) 



Pythium proliferum Schenk, Verhandl. Phys.-Med. Gesell. Wurzburg, A. F., 



9:27, pi. 1, figs. 30-41. 1859. Non de Bary, Jahrb. wiss. Bot., 2: 182. 



1860. 

 Pythium globosum Schenk, op. cit., 9: 27, pi. 1, figs. 42-47. 1859. 

 Pythium globosum Walz, pro parte, Bot. Zeitung, 28: 553, pi. 9, figs. 13-15. 



1870. 

 Lagcnidium globosum Lindstedt, Synopsis der Saprolegnieen, p. 54. Berlin, 



1872. 

 Myzocytium globosum (Schenk) Cornu, Ann. Sci. Nat. Bot., V, 15: 21. 1872. 



Sporangia from one to twenty, in beadlike chains, broadly fusiform, 

 broadly ellipsoidal and 15.7-26 \x long by 13-16 \i wide, or spherical 

 and 14.4-25 u, in diameter, separated by two-layered refractive walls up 

 to 2.4 ji. thick, each forming a single narrowly cylindrical predominantly 

 equatorial discharge tube about 2-3 u. in diameter, which extends for a 

 variable distance beyond the host wall; zoospores from four to twenty, 

 bean-shaped, laterally biflagellate, 5.4-10 \i long by 3.6-6 \x wide, under- 

 going their final maturation in an evanescent vesicle formed at the 

 orifice; female and male gametangia generally similar to the sporangia 

 in size and shape or the female sometimes more spherical; oospore 

 spherical, 10-25 \x in diameter, lying loosely in the gametangium, with 

 a smooth colorless double wall and a large eccentric globule, generally 

 attached to the persistent fertilization tube, germination not observed. 



Parasitic in Spirogyra sp., Zygnema sp., "Conferva" Schenk (he. 

 cit.), Closterium didymotocum, C. acerosum, Cosmarium connatum, 

 Reinsch(1878: 299, pi. 1 7, figs. 6, 9), Zygnema sp., Spirogyra sp., Mou- 

 geotiasp., Cladophora sp., Oedogonium sp., Zopf (1884: 159, pi. 14, figs. 

 6-34), Cladophora sp., Spirogyra sp., Zygnema sp., Walz (he. cit.), 

 host (?), Mougeotia pleurocarpus, Schroeter (1885: 227), Minden (1915: 



