220 



PTEKIDOPHYTA. 



germination, water is absorbed, the two sides separate slightly, as 

 valves (Fig. 220 A), and a long vermiform mass of gelatinous, 

 parenchymatoua cells (Fig. 220), swollen by the water, emerges, 

 bearing a large number of sori arranged pinnately. Each sorus 

 (.<??) is covered by a thin indusium. (The thin covering may be 

 considered an indusium physiologically, though not morpho- 

 logically). 



Manilla qiiadrifolia, in Europe. Many species are found in Australia. The 



Sf 



FIG. 220. Morsi'Hn salaatri.t : A the 

 f-porocarp commencing- to germinate ; B 

 a more advanced stage of germination. 



FIG. 221. Pilitlarin globulifera (natural 

 size) : s sporocarps ; b leaves ; fc tbe 

 growing point; r roots. 



ps 01 j/. saivatrix were the means of saving the Burke ex- 

 :lor of Australia, and hence this species has earned its specific 



nutritious sporocarps of M. salvatrix were 



pedition in the interior 



name. 



'Pilularia has linear leaves, without lamina. The sporocarps are 

 spheroid (Fig. 221), brown and hard, and situated near the base of 

 tlu- leaves. They are 2-4 chambered and open by a corresponding 

 number of valves. 



