288 



SPOROPHYTE OF BOTRYCHIUM 



of one of the species which become green on reaching the sur- 

 face of the soil and in a closely allied order of tropical ferns. 

 the sexual generation is normally a green thallus strikingly like 

 some of the simpler Jungermaniales. 



FIG. 218. The gametophyte and young sporophyte of Botrychium: A, 

 tuberous appearance of the gametophyte em, a young sporophyte or em- 

 bryo developing in one of the archegonia. B, a section of gametophyte 

 ar, archegonia; an, antheridia. C, two antheridia in section. D, male 

 gamete. E, archegoninm before dissolution of canal cells. F, gametospore 

 in two-cell stage of germination. G, young sporophyte with roots and 

 first leaf developed but still attached by foot to the round gametophyte, 

 gin. A-F After Jeffrey. 



(b) The Germination of the Gametospore. The early develop- 

 ment of the sporophyte resembles Anthoceros in many respects. 

 The gametospore divides into two cells (Fig. 218, F), from -the 

 lower of which a large foot is formed, and from the upper cell 

 the short stem and root arise. Later, the -first leaf or cotyledon 

 is formed from the stem. This development of the sporophyte 



