CORDAITALES 



179 



THE GAMETOPHYTES 



Even less is known about the gametophytes than in the Cy- 

 cadofilicales, but some silicified material has been sectioned. 



The male gametophyte. — The male gametophyte is better known 

 than the female, probably on account of the protection aflforded by 

 the exine. Sections show that the interior was multicellular. The 

 best views are seen in sections 

 of the upper part of the nucellus 



Fig. 190. — Samaropsis pitcairnlae (Dory- 

 Cordaites): part of fruiting branch, bear- 

 ing winged seeds; natural size. — After Car- 



RUTHERS." 



Fig. 191. — Cordaianthus pit- 

 cairniae: piece of stem with a 

 shoot bearing male strobili on 

 the left, and one with female 

 strobiH on the right; natural 

 size.— After Grand d'Eury.^" 



(fig. 196). It has been suggested that since pollen grains in the mi- 

 cropylar canal are larger than apparently mature pollen grains in 

 the microsporangium, there is growth after shedding. This is hardly 

 probable in forms with a thick spore coat. In well-known living 

 anemophilous forms, the dry pollen swells when it becomes wet. 

 Just so, in these fossil forms, the pollen would be likely to swell upon 

 reaching the pollination drop. The pollen grains in the micropylar 

 canal, of course, are mature; but whether the cells are vegetative or 

 spermatogenous is not certain. It is very likely that there was both 

 vegetative and spermatogenous tissue in the pollen grains. If well- 

 preserved material in late stages should be found and sectioned, it 

 seems safe to predict that it will show that the Cordaitales had 

 swimming sperms. 



The female gametophyte. — Nothing is known about the female 

 gametophyte, except that it must have been elongated. The ovule is 



