The Fungi— Molds 361 



cell in a septate plant has one or more nuclei, while in non-septate 

 molds the nuclei are seen spaced at regular intervals within the 

 hyphae, and the protoplasm appears to be continuous with no cross- 

 wall effect. Both sexual and asexual reproduction are demon- 

 strable in molds, with the exception of members in the class of 

 Fungi Imperfecti. 



PHYCOMYCETES 

 Phycomycetes are often called the lower fungi since they closely 

 resemble the green algae in morphology. Members of this class 

 of fungi are non-septate. Asexual multiplication is by the produc- 

 tion of spores borne within a structure called a sporangium, and 

 the stalk upon which this fruiting body develops is called a spo- 

 rangiophore. Phycomycetes also possess so-called plus and minus 

 types of hyphae which conjugate and form a spore designated as- 

 a ZYGOSPORE, the product of sexual reproduction. The Rhizopus 

 and Mucor genera belong in this group of molds. 



ASCOMYCETES 

 These fungi are septate, and they multiply asexually by the 

 pinching of the tips of the fertile hyphae to form structures called 

 coNiDiA. Sexual reproduction of members of the ascomycetes is by 

 a process in which spores are formed within a sac (ascus) as the 

 result of the fusion of two hyphae which coil together. 



BASIDIOMYCETES 

 Basidiomycetes are septate molds in which sexual multiplication 

 occurs by the formation of spores borne externally on a club-shaped 

 stalk called a basidium; the spores are called basidiospores. The 

 difference between the sexual and the asexual types of reproduction 

 of basidiomycetes is difficult to distinguish. 



FUNGI IMPERFECTI 

 These fungi derive their name from the fact that no sexual 

 spores are demonstrable, and since asexual reproduction is con- 

 sidered to be an imperfect stage, these molds have been designated 

 Imperfecti. It has been suggested that these plants might possibly 



