T 54 



MORPHOLOGY 



formed first a rather large, undifferentiated mass of tissue (fig. 365) 

 in which at least three growing points (foot, root, and stem) become 



organized, the leaf appearing 

 later. In this embryogeny of 

 Botrychium there is a general 

 resemblance to the Lycopodiales 

 in the belated organization of 

 some body region; and a still 

 further resemblance to those 

 species of Lyco podium in which 

 the embryo begins with the 



Fig. 361. — Gametophyte of Botrychium: development of a protocorm 

 antheridia in dorsal ridge; archegonia along the fa j-N The same belated ap- 

 slopes; region of endophytic fungus in ventral 



region. -After Jeffrey. pearance of one or more body 



regions has been observed also 

 in species of Ophioglossum. In the whole group there seems to be no 

 such early and complete differentiation of the body regions as in 

 Equisetales and Filicales. 



362 363 364 365 



Figs. 362-365. — Archegonium and embryo of Botrychium Lunar ia: 362, fertilized 

 egg, in venter of archegonium; 363, first division of egg; 364, quadrant stage; 365, later 

 stage of embryo, the body regions not yet differentiated. — After BRDCHMANN. 



Conclusions. — The Ophioglossales have certain features in common 

 with the Lycopodiales, notably the structure of the gametophyte, the 

 adaxial relation of sporangia to sporophylls, and the irregular and some- 

 what indefinite development of the embryo in its early stages. The 

 "fertile spike," however, may have arisen from lateral branches, which 

 would eliminate this feature of the resemblance to Lycopodiales. The 

 same kind of irregular and indefinite development of the embryo proba- 

 bly also occurs among the Marattiaceae, so that this feature finds its 

 resemblance among both Filicales and Lycopodiales. In the reduced 

 number of foliage leaves and their corresponding increase in size, and 

 in the sperms, the resemblance is decidedly with the Filicales. In vas- 



