Fungi 405 



Reproduction. The development of the vegetative body 

 culminates in the production of numerous fruiting bodies. 

 Among the simpler forms of fungi the reproductive structures, 

 or fruiting bodies, may consist merely of specialized reproduc- 

 tive cells cut off from the ends of hyphae, or of ends of hyphae 

 that become enlarged and form several or many reproductive 

 cells inside them. The reproductive cells are called spores, and 

 the cells in which they are formed are called sporangia (singular, 

 sporangium). Probably no other group of plants compares 

 with the fungi in the variety of its reproductive bodies. Cer- 

 tainly no other plants produce such enormous numbers of 

 spores in comparison with the size of the plants. As a conse- 

 quence of the small size and great number of these spores, they are 

 carried long distances by the wind and scattered everywhere. 

 Furthermore, when the spores germinate and develop a new myce- 

 lium, a second crop of spores may be produced within a few days. 

 In this way, under favorable conditions, as many as 120 crops of 

 bread mold may be grown in a year. 



Among the more complex and fleshy fungi the mycelium may 

 grow for weeks and months before reproductive structures begin 

 to develop. There may be large structures formed by the con- 

 solidation of large numbers of hyphae, part of which later produce 

 spores. The fruiting bodies may take the form of small disks, 

 saucers, cups, hollow capsules, solid balls, toadstools, woody 

 brackets, or irregular coralline masses. 



Germination of spores. The spores of many of the parasitic 

 fungi germinate readily when placed in water. However, un- 

 less the sporeling is in contact with its proper host plant, it fails 

 to develop further and dies. Of course, many of them have 

 been grown on nutrient media. 



It is difficult to germinate the spores of many of the saprophytic 

 fungi, like the puffballs and toadstools, because of their very 

 exacting requirements. Such spores may be germinated only 

 in a nutrient solution containing certain sugars, proteins, and 



