DEVELOPMENT OF PLANTS 



317 



tion is not often met with, owing to the fact that, like the sporo- 

 phyte, its development is associated with mycorrhizal fungi and 

 consequently it is usually completely buried in the soil and usually 

 quite devoid of chlorophyll. The various stages in the germina- 

 tion of the spores have never been observed, but the mature gam- 

 etophyte of Botrychium was found a few years ago by Jefifrey 



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

 tuberous appearance of the gametophyte — e, 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, archegonium 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, gm. 

 A. F. — After Jeffrey. 



and carefully studied. It appeared as a rather tuberous body 

 that is provided with numerous rhizoids and a growing apical 

 cell as in the Bryophyta (Fig. 218, A, B). The archegonia and 

 antheridia are usually borne upon the upper surface of the game- 



