458 



Bulletin 315 



Sporangiophores of different form and different height, shorter, mostly 

 2-5 mm, high, pure sympodially branched; branches usually 5-6, alter- 

 nating right and left, short, often appearing as 

 sessile, straight or slightly bent or curved; 

 longer sporangiophores 0.5-1.5 cm., irregularly 

 monopodially or sympodially branched; sporan-, 

 gia globose, at first light brown then becoming 

 gray-brown, those of longer sporangiophores 

 with dissolving membrane while those of the 

 shorter possess a firm membrane and often fall 

 intact; membrane either finely spiny or smooth; 

 columella sessile, globose, hyaline, smooth, 15- 

 42;a in diameter depending on size of sporangium ; 

 spores oval or broad ellipsoidal, 3-4 by 5-6^1, 

 smooth, singly hyaline, in mass weak gray. 



Heterothallic ; zygospores globose; exospore red 

 brown, with long thorn-like pointed warts that 

 Fig. loj. —Miicor circinel- ^^^ streaked longitudinally; chlamydospores 



loides van Tiegh. Shoiv- intercalary, barrel-shaped, smooth, hyaline. 



iiip method of branching, of r? . i j • i^ 



sporangiophore, sporan- Zygospores not observed m our cultures. 



gia, columella with collar, Hab. Isolated in July, 1910, and March, 



and spores, X 236.6 r ^ c ^^ i • j. ^ ^ ^ c 



^ 191 1, from oat field and experimental plats of 



Plant-Breeding Department, Cornell University, Ithaca, N. Y., by the 



writer. Plant pathology herbarium No. 5,901. 



Mucor griseo-cyanus Hagem, Untersuch. \x. Norw. Mucorineen 1:28-29. 

 fig. g. 1908; reprint from Vid.-Selsk. Skr. I, Math.-Naturv. Klasse 

 No. 7, 1907. Lendner, Les Mucorinees de la Suisse, 86-87. fig. zg. 

 1908. 



Colonies grown at room temperature (15° C.) blue-gray, at 20-25° C. 

 deep black-blue; sporangiophores at first erect, soon, however, sinking 

 down, 2-3 cm. long, 8-1 2;u thick, sympodially branched with branches 

 again richly branched, generally with a septum on the main branch just 

 above place of origin of side branches; sporangia globose, at maturity 

 deep blue-black, opaque, with spore mass invisible, 60-SoM in diameter; 

 sporangial wall blue-gray to blue-black, incrusted, dissolving, breaking, 

 or remaining intact; columella mostly globose, seldom somewhat oval, 

 30-45)Li in diameter, with smooth membrane and colorless contents; spores 

 oval or broad ellipsoidal, 4-6 by 2.5-4/x; zygospores unknown. 



Hab. Isolated from humous soil near Christiania, Norway, Hagem; 

 Canton of Geneva, Switzerland, Lendner. 



Mucor corticolus Hagem, Neue Untersuch. li. Norw. Mucorineen. Ann. 

 Myc. 8: 277-279. fig. 8. 1910. 



