SECTION XI. 

 FERMENTATION BY ZYGOMYCETES. 



CHAPTER XLIII. 



MORPHOLOGY AND SYSTEMATOLOGY OF THE MUCORS. 



§ 234.— Subdivision of the Order of Zygomycetes. 



The Order of Zi/gomyceteg (^221) is characterised by the 

 capacity of forming zygospores. According as these resting 

 cells are able to envelop themselves in a more or less completely 

 developed capsule, or remain naked, the corresponding Zygo- 

 mycetes are divided into two sub-groups. The higher of these, 

 viz. the one forming the spore capsules, has received the name, 

 " carposporangial," from Brefeld, who united the whole of the 

 members into a family, a few particulars of which will be given 

 in § 237. Antithetical to these are the remaining, or " exo- 

 sporangial." Ztjijomycetes, as they were termed by Brefeld. It is 

 with this (larger) sub-group, the sporogenic organs of which 

 remain naked, that we have first to deal. 



The occurrence of several methods of fructification in one 

 and the same species of fungus has already been mentioned in 

 § 223, and is specially prevalent among the Zyriomycetes. Apart 

 from the characteristic zygospores, they are able to ensure the 

 reproduction of the individual in other ways, special aptitude 

 in this direction being exhibited by the genus Choanephora, 

 which, in addition to zygospores and gemmse, also puts forth 

 conidia and endospores. In all other Zygomycetes only one 

 or other of the two last-named methods of fructification is 

 exhibited by any one individual. Sporangial fructification is 

 characteristic of the Mucor family, a number of examples of 

 which will be more closely considered later on. 



The other Zygomycetes, on the contrary, exhibit conidial 

 fructification, and are divided into three families, which do not 

 come directly within the scope of the pi-esent work, and v>-ill 

 therefore be dismissed with a few brief explanatory remarks. 

 The family of the Entomophthorese forms a connecting link 

 between the orders of Zygomycetes and Oomycetes. The species of 

 this family are almost exclusively parasitic on living organisms 

 (insects, fungi, ferns), and one of them will, from its efi'ects at 

 any rate, be, superficially, known to the reader, namely, E)iipusa 



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