Fungous Flora of the Soil 447 



6-17 iJL in diameter, mostly somewhat longer than broad, with thick double 

 membrane on which are seen meridian -like folds, light pale gray, contents 

 colorless; zygospores globose or barrel-shaped, i6o-2 20;u in diameter; 

 exospore firm, brown-black, opaque, closely beset with half-globose 

 high warts; endospore colorless, thick, with small outgrowths filling the 

 warts of the exospore; suspensors swollen, commonly unequal, almost 

 as broad as the zygospore; azygospore observed. 



Isolated from soil, Norway, Hagem; Germany, Adametz; isolated 

 repeatedly by writer from plant -breeding plats near Cornell University 

 during winter 1910-1911. Plant pathology herbarium No. 5,895. 



Rhizopus nigricans var. minor n. var. 



Differs from type in the following particulars: 

 Sporangiophores never attain a height of more 

 than 2.5 mm. and a maximum thickness of 28/^ 

 (type 4 mm. maximum height by 42^l maximum 

 thickness) . The clusters of sporangiophores vary from 

 I to 5, never more (type 1-5, sometimes 10). Spores 

 are more uniform in size and constantly smaller, 

 4.5-10 by 4.2-6.6/i, and of a dark fuliginous color. 



Hab. Soil taken from plant-breeding plats, Cornell 

 University, Ithaca, N. Y., fall 19 10. 



Rhizopus nodosus Namyslowski, Rhizopus nigricans 

 et les conditions de la formation de ses zygospores. 

 Bui. Intern. Acad. Sci. Cracovie No. 7. 1906. 

 Lendner, Les Mucorinees de la Suisse, 122-123. 

 fig. 45. 1908. 



Syn. Mucor Norvegicus Hagem, Untersuch. ii. Norw. 

 Mucorineen 1 : 39-40, jig. 75. 1908; reprint from 

 Vid.-Selsk. Skr. I, Math.-Naturv. Klasse No. 7. Fig. 102 . — Rhizopus 

 1907, nigricnas Ehren. var. 



Mucor nodosus (Namy.) Hagem, Neue Untersuch. minor. Showing spo- 

 il. Norw. Mucorineen. Ann. Myc. 8: 280. 1910. rangiophores, rhizoids, 



Mycelium at first cottony white, then finally ^pLsfx^J^j "" ^''' 

 becoming tinted with ocher-yellow. In the midst 



of the mycelium and on the stolons are found stalks temiinated by 

 sporangia; stalks simple or branched, the branches terminated by 

 sporangia, often swollen at some one point, 1-2 mm. high, 12-18/i thick, 

 with smooth, thick membrane that is hyaline at first, then finally 

 becoming pale ocher-yellow or brown. 



When the swellings are at the extremity of the stalk, they give rise to a 

 group of 3-5 sporangiophores terminated by sporangia, sporangiophores 

 1-2 mm. high; sporangia round, ioo-2oo)u in diameter, average 130JU; 

 spores 6-9 by 4-6;u, with longitudinal stripes, giving rise, if they are sown 

 on saccharose, to filamentous mycelium producing chlamydospores 16-34JU 



