CRYPTOGAMS 



4] 9 



which are scattered by the wind ; they are utilised by the Tartars iu the prepara- 

 tion of earth-bread. 



A peculiar mode of development is exhibited by the genus Cladonia ( 87 ), whose 

 primary thallus consists of small horizontal scales attached directly to the ground, 

 from which rises an erect portion, the PODETIUM, of varying form and structure in 

 the different species. In some cases the podetia are stalked and funnel-shaped, 

 bearing on the margin or on outgrowths from it knob-like apothecia, which in 

 C. pxyidata are brown, in C. coccifera (Fig. 

 370) bright red. In other species the erect 

 podetia are slender and cylindrical, simple 

 or forked ; in C. rangiferina, Reindeer Moss, 

 which has a world- wide distribution, particu- 



larly in the tundras of the North, the podetia vJlr /^*Jk\ .'/ 



are finely branched (Fig. 371), and bear the 

 small brown apothecia at the ends of the 

 branches. The primary thallus of this species 

 soon disappears. 



The ascus - fructifications (apothecia or 



A 



FIG. 371. Cladonia rangiferina. A, Sterile ; B, with 

 ascns-fruit at the, ends of the branches. (Nat 

 si/e.) 



A 



Fio. 3"!-2.f'olli'ina Ki-isjnini. A, Carpo- 

 gonium (c) with its trichogyne (t) 

 (X 405). B, Apex of the trichogyne 

 with the. spermatiuni (.<) attached 

 (x 1125). (After E. BAVR.) 



perithecia) of the Lichens originate, as STAHL, and more recently BAUK (**) have 

 shown, from carpogonia or female sexual organs, which are frequently present in 

 large numbers on young lobes of the thallus. The carpogonium (Fig. 372) is here 

 a inulticellular filament, the lower part of which is spirally coiled, while it continues 

 above into a trichogyne composed of elongated cells, and projecting from the surface 

 of the thallus. All the cells are uninucleate and communicate with one another by 

 means of pits. Those of the lower part of the filament contain abundant protoplasm. 

 Apart from their multicellular nature these structures recall the carpogonia found in 

 the Florideae. The spermatia, which originate in spermogonia (Fig. 373), are pre- 

 sumably the male sexual cells. The spermatia develop in different ways ( w ). In 

 some cases the inner wall of the spermogonium is lined with simple or branched 

 hyphal branches from the ends of which the spermatia are abstricted (Peltigcra, 



