FOSSIL GYMNOSPERMS 



145 



in fact the whole seed with the exception of the beak (Fig. 99). 

 The evident absence of a suspensor at once suggests Ginkgo, but 

 the nearly complete disappearance of the endosperm is without a 

 parallel among Gymnosperms, so far as studied. 



The morphological features of Bennettitales have been 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, promises to supply much additional in- 

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

 sion of the L'nited States National Museum, and of the Yale 

 University Museum, and the minuter structural characters are 

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

 liminary papers concerning the " male flower " 4 and the " fe- 

 male fructification " 5 of species of Cycadeoidea. In some of 

 the species, as C. Wielandi, the ovulate strobilus seems to con- 

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



FIG. 100. Cycadeoidea Wielandi, transverse section of a portion of the ovulate strobilus, 

 showing the seed-stalks with their central bundles, and the interseminal scales 

 packed in between. From a photograph by C. E. BEECHER from a section made by 

 G. K. WIELAND from a specimen in Yale University Museum. 



tites Gibsonianus, as given above. There is the same broad 

 receptacle bearing thickly set stalked seeds and interseminal 

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

 form an ovoid body (Fig. 98). 



The discovery of microsporophylls and of bisporangiate 



