FOSSIL GYMNOSPERMS 



145 



in fact the whole seed with the exception of the beak (Fig. 90). 

 The evident absence of a snspensor at once suggests Ginkgo, Lut 

 the nearly complete disappearance of the endosperm is without a 

 parallel among Gymnosperms, so far as studied. 



The morphological features of Bennettitales have liecn ob- 

 tained heretofore almost exclusively from European material, 

 but the remarkably rich display of this group in the Mesozoic 

 flora of the United States, as developed by Professor Lester F. 

 Ward and his associates, 2:iromises to supply mu(di additional in- 

 formation. Largo collections of this material are in the posses- 

 sion of the United States National J\Liseum, and of the Yale 

 L'niversity Museum, and the minuter structural characters are 

 being investigated by Dr. G. II. Wieland, who has published pre- 

 liminary ]iapers concerning the " male flower " ^ and the " fe- 

 male fructitication " " of species of Cycadeoidea. In some of 

 the species, as C. Wielandi, the ovulate strolhlus seems to e<m- 

 form almost exactly to the description of the stroljilus of Bennet- 



Fio. 100. — Pi/i-ailtfiiiled ]\ I 1 1 h ti iii^\ 1-1 s( n u nt ip iti u it tli \ ul itt sti 1 ihis, 

 showing the sced-bt ill s w itii then CLOtitil bumllcs, an<l the intci^tiniiial scales 

 packed in between. — From a pliotograpli by C. E. Beeciier from a section made by 

 G. K. WiELANi) from a specimen in Yale University Museum. 



tites GdimniariKS, as given above. There is tlic same broad 

 receptacle bearing thickly set stalked seeds and intersemiual 

 scales (Fig. 100), and all ensheathed by overlapping bracts to 

 form an ovoid Ijody (Fig. OS). 



The discovery of microsporophylls and of Idsporangiate 



