184 



BOTANY. 



FlQ. 105.— Sexual organs 

 of a Cup-fungus (Peziza 

 omphalodes). The two car- 



Eogones are globular ; each 

 as a curved trichogyne. 

 The antherids are curved 

 branches from below the orraduallv takes 

 carpogones. Much magni- ^ •' 



fled. frn-TTi of 



of the ends of certain of the filaments of the plant into 

 globular or ovoid cells, the carpo- 

 gones, each having a projection 

 (trichogyne) . From below each car- 

 pogone a slender branch grows out, 

 and becomes the antherid (Fig. 106). 

 340. In the few plants in which 

 it is known fertilization is effected 

 by contact of the antherid with the 

 trichogyne. As a result numerous 

 branches start out from below the 

 carpogone, and growing upward 

 form a dense felted mass which 

 on the size and 

 form of the spore-fruit. Some 

 of the filaments of the spore-fruit become enlarged into 

 sacs in which spores are developed (Fig. 107), while the 

 others {parcqiliyses) make up the sterile or protective tissue. 

 The spore-sacs groiv so that all reach tlie same height, and 

 make up the inner surface of the cup (Fig. 106). 



341. While tlic foregoing may be regarded as the typical 

 structure of the plants of this order, it presents several 

 modifications, tho most important of which is that due to 

 the peculiar parasitism occurring in three families which 

 gives rise to the " lichen " structure. These have gener- 

 ally been regarded as constituting a separate order, but it 

 is now known that there are "lichen-forming" plants in 

 widely separated groups. However, since the greatest 

 number of species occurs in this order, they may be studied 

 best here by the beginner. 



342. The Lichens are among the most interesting plants 

 of the vegetable kingdom. They are not only often of ex- 



