SKUT. I 



CRYPTOGAMS 



46/ 



dehisceuce is similar in these also, but the boat-shaped portion of the wall is 

 smaller, the valves extendinff to the base. 



Jj 



W. 





I 



Fig. 415. — A-E, Sclaginella stolanifera, successive stages in the germination of a microspore ; 

 p, prothallial cell ; w, wall-cells of antheridiiim ; .<, spermatogenous cells ; A, B, D, lateral, 

 C, dorsal view. In K the prothallial cell is not visible, the disorganised wall-cells enclose 

 the spermatozoid mother-cells ; F, sperinatozoids of Selaginella cuspida.ta. (After Belajeff. 

 A-E X 640, F X 780.) 



The microspores begin their development while still enclosed within the 

 sporangium. The spore first divides into a small lenticular vegetative cell, which 



Fio. 41(3. — Seluginclla Miuttnsii. A, Ruptured niacruspore seen from above showing tlic prothallus 

 with three groups of rhizoids and several archegonia. (x 112.) B, Longitudinal section of 

 the prothallus showing two archegonia in which embryos are developing, (x ITi.) (After 

 Bri'lhmann.) 



corresponds to the rhizoid cell of Salvinia, and into a large cell, which divides 

 successively into eight sterile prothallial or wall cells and two or four central 



