98 



MYCOLOGY 



The important genera of the family are Miicor, Rhizopus, Phycomy- 

 ces, Ahsidia, Sporodinia, Thamnidium, Dicranophora, Filaira and Pilo- 

 boliis. The genus Mucor, a key for the identification of the species will 

 be given at the end of the book, was estabhshed in 1729 by Micheli. 

 The genus may be divided into three groups of species. The first 

 division includes those species with unbranched sporangiophores, such 

 as Mucor mucedo. The second group comprises the moulds with clus- 

 tered branches of the sporangiophores, as Mucor cor ymbifer, M. erectus, 

 M. fragilis, M. pusillus, M. racemosus, and M. tenuis. The third sec- 

 tion is made up of species the sporangiophores of which show sympodial 



Fig. 30. — Details of Chlamydomucor racemosus showing oidia, sporangia and zygo- 

 spore formation. 



branching. Such are Mucor alternans, M. circinelloides, M. javanicus, 

 M. Rouxii and M. spinosus. (Also consult pages 695-702.) 



The oldest known species, Mucor mucedo, was described fully for the 

 first time by O. Brefeld in 1872. Stiff sporangiophores, 30 to 401J, 

 thick, arise from the mycelium and are 2 to 15 cm. in height. Each 

 bears a single globular sporangium 100 to 200/i in diameter and the 

 sporangial wall is beset with fine needles of calcium oxalate. The spores 

 are ellipsoidal 3 to 6/i by 6 to 12/i with faint yellowish cell contents. As 

 previously described, conjugation is between two similar gametes from 

 + and — mycelia. Mucor racemosus, also known as Chlamydomucor 



