0ARP0PH7TA. 



187 



a term which is still in common 

 use. 



345. The spores of lichens are 

 produced in sacs, which are simi- 

 lar to those of other Cup-fungi. 

 In many common species the 

 spore-bearing disks (called apothe- 

 cia) are large and readily seen 

 (Fig. 108, A and B), while in 

 others they are small and not 

 easily made out. In other species 

 the spore-sacs are immersed in 

 cavities which show only as black- 

 ish lines or dots on the surface of 

 the lichen-body. 



346 The spores germinate by 

 sending out one or more tubes 

 which develop directly into the 

 ordinary filaments of the lichen- 



1 ■'■' "I"**.?**!* 



FlO. 109. FIG. UO. 



Fio. 109.— Green plants (gonidia) dissected from different Lichens, 

 showing attachment of the parasitic illaments ; several are dividing. All 

 highly magnified. 



Fio. no.— a vertical section of a common Lichen (Physoia stellaris) 

 through a fruit-disk, showing spore-sacs at th, intermingled with slender 

 filaments (paraphyses), t ; gonidia (species of Protococcus) at 0, g' ; cm, the 

 interlacing branching filaments, hecomlug harder and denser at cc and 7i. 

 Much magnified. 



