DEVELOPMENT OF PLANTS 229 



the simplest cases one or more sacs. These bodies are known as 

 asci (sing, ascus) and they contain more frequently eight spores, 

 called ascospores (Fig. 160), which must be distinguished from 

 the spores or conidia mentioned above. The gametospore germi- 

 nates as a parasite on the mother plant as in the red algae. 

 The sexual process results, in the majority of forms, not only 

 in the formation of asci, but numerous hyphae from the my- 

 celium are also stimulated to growth and become associated 

 with the asci in various ways, recalling the cystocarps of the red 

 algae. As a result fruit bodies of various forms, called ascocarps 

 or perithecia, are developed which often become the conspicuous 

 part of the fungus (Figs. 155-158). The ascospores germinate 

 immediately or after a period of rest and form a new mycelium. 

 It should be stated that the ascocarps have not been connected, 

 in many cases, with sexual processes, and it is inferred that sexu- 

 ality has been lost along with other characters as a consequence 

 of the degeneracy resulting from parasitic and saprophytic 

 habits. Only a few of the more important orders will be dis- 

 cussed. 



83. Order a. Pezizales or the Cup Fungi. These plants are 

 characterized by the formation of fleshy, leathery or gelatinous 



FIG. 139. One of the common cup fungi, order Pezizales, with broadly 

 opened ascocarps. Common upon rich humus soil and decaying wood. 



cup-like ascocarps that range in size from mere specks to forms 

 four or five inches in diameter (Fig. 139). The mycelium lives 

 upon the humus in the ground or on decaying plants and ap- 

 parently in this and the next order frequently develops the asco- 

 carps directly without a reproductive process. In Pyronema 

 and many other forms, however, Dodge has' shown that reproduc- 



