126 Plant Biology 



the formation of a saclike ascus in which are formed ascospores. They 

 all possess organized nuclei and all are filamentous, with such exceptions 

 as certain types of yeasts. When hyphae are present, they are septate 

 (cross walls). Many species are ot great economic importance in the 



Fig. 38. — Blue-green mold {Aspergillus sp.) of the phylum Eumycophyta, class 

 Ascomycetes. A, Portion of mycelium, showing spore formation; B-C, spore and 

 its germination ; D-F, formation of ascospores ; D, hypha twisted into a coil ; E, 

 coiled hypha surrounded by an ascus (sac) ; F, coiled hypha forming ascospores 

 within the ascus. 



Conidia (spores) 



\ » 



I 



Sporophore-- 



Rhi^oid 



Fig. 39. — Bluish-green mold {Penicillium sp.) of the phylum Eumycophyta, 

 class Ascomycetes. Such molds do not frequently form ascospores. although a 

 few species do so occasionally. 



manufacture of foods, as cheeses by such types as Penicillium camemherti 

 or P. requeforti, in the production of antibiotics by such types as Peni- 

 cillium notatum, etc., in the fermentation of sugars by yeasts, by para- 



