May, 1907] 



Mycological Bulletin No. 77 



325 



a 



a Spir.ulose mycelium of Mncor fusiger. b Spores of same, 

 c Columella of Mucor stercoreus. d Spores of same, e Columella of 

 Phjcomyces nitens. f Spores of same. 



Fig. 247. Illustrations of Moulds. 



MUCOR. 



This genus is characterized by simple or branched, but not dichotom- 

 ously branched, sporangiophores. The membrane of the sporangium is 

 not cuticularized and soon disappears. The sporangia are of one kind and 

 are furnished with columella. 



MuCOR MUCEDO LiNNAEUS. 



The mycelium is white at first, then brown or even black. The 

 sporangiophores are usually in clusters of three or more, reaching 5 mm. 

 in height. The columella is very prominent, but finally collapses. The 

 spores are gloliose, oval or irregular. This is the common black mould of 

 bread. The following names are also given to this species, Mucor stoloiii- 

 fcr, Rhicopus nigricans. 



Mucor stercoreus (Tode) Link. 



The .sporangiophores are erect, undivided, gray; the sporangia are large, 

 yellowish, lirownish when old; the membrane disappears and leaves a 

 collar at the base ; the columella is variously shaped, cylindrical or conical ; 

 spores somewhat elliptical. It grows on dung. Mucor miiccdo Fresenius 

 has also been applied to this mould. 



Mucor fusiger Link. 



The sporangiophores are simple, erect, bulbous below, but attenuated 

 upwards, gray to brown in color: columella is large; spores spindle 

 slipped ; the aerial mycelirm is divided into thorny l^ranchcs. It grows 

 6*1 Agarics. 



