240 PHYLUM VII. CARPOMYCETEAE 



(a) Look for Spot Fungi on the hosts mentioned above, and 

 especially for the minute black fruits in the spots, making 

 sections of the latter. 



(6) Look for Black-dot Fungi on leaves, fruits and twigs of 

 many plants, especially for Colletotrichum on bean pods. 



(c) Look for Molds on leaves, as well as on some dead 

 tissues. 



414. Summary for the Higher Fungi. The theory 

 underlying the foregoing account of the Higher Fungi is 

 that these plants have been derived from the Red Algae 

 by modifications, mostly degradational, due to the change 

 from a holophytic to a hysterophytic habit, accompanied 

 by the equally significant change from aquatic to non- 

 aquatic life. It is here considered probable that the 

 earliest fungi were those known as "lichens," which 

 became parasitic upon small algae. In them the dom- 

 inant modification was, of course, the disappearance of 

 chlorophyll, and the reduction of the plant body. In 

 the fruit resulting from the fertilization of the egg, the 

 homologues of the carpospores of the Red Algae divided 

 internally into spores, thus changing the carpospore 

 into the ascus, and resulting in the considerable multi- 

 plication of spores. Thus the asci and ascospores be- 

 came characteristic structures in the fruits of the fungi, 

 and gave name to the first class Ascosporeae. 



415. Later, in the subterranean fruits of the truffles 

 another modification took place whereby the spores 

 instead of remaining within the ascus, push out beyond 

 the ascus wall, so as to be more easily dispersed. In 

 this way the basidium with its basidiospores arose from 

 the ascus and its ascospores. These are thus to be re- 

 garded as homologous structures, in which the later- 

 formed basidia have superior means for dispersing their 

 spores. 



416. In like manner in the Brand Fungi we find 



