131 0. L\ Wieland— Williamsonian Tribe. 



gestcd no relationship to the imperfectly known Williamsonia, 

 in fact could scarcely have been fairly interpreted short of the 

 broader knowledge of the past ten years. And precisely 

 because of this very new type of ovulate cone it was not seri- 

 ously suspected that the great majority of fossil cycad trunks 

 bore fruits like it or could be other than ordinary cone-bearing 

 forms. While Saporta(lO) with all the weight of authority, and 

 having in his hands the splendid James Yates collection of Wil- 

 liarasonias brought to the Paris Museum by Brongniart in 1843 

 — a collection the equal if not the superior of any that remained 

 on English soil — rejected the idea of any organic connection 

 between the Williamsonian " pyriform axes" and " carpel lary 

 disks," and the " Zamia giyas" fronds. In which he was fol- 

 lowed by most continental botanists, with various suggestions 

 as to the possible affinities of the Yorkshire coast specimens, 

 ranging from the Cordaites-like Yuccites to Orobanche (9). 



Thus it was that the idea that complexity of structure might 

 lie hidden behind the great array of Mesozoic cycad stems 

 and leaves, failed of development and study, and came to 

 receive but scant mention in paleontologic texts. And so 

 rested the subject until the structure of the Cycacleoidea flow- 

 ers was at last elaborated from the American specimens, and 

 the true position of Williamsonia as the representative of a 

 slender-stemmed family closely related to the Cycadeoideae, 

 made apparent (12). While at the present time collateral evi- 

 dence has so accumulated that nothing in Paleobotany is more 

 clearly established than that a great complex of Williamsonia- 

 like plants, including other families yet to be determined, 

 spread over the earth in the Mesozoic. As Scott has said, the 

 application of comparative criteria may lead one to the con- 

 clusion that thirty to forty thousand of these species existed in 

 Mesozoic times. Moreover, every year that goes by strength- 

 ens the view that of all post-Paleozoic gymnosperms the type 

 represented by Williamsonia is the one most generalized, 

 plastic, and capable of floral variation. 



For as is now so clearly discerned, the silicified trunks of 

 the near family Cycadeoideae are simply the bizarre relatives 

 capable of fossilization as entire plants with their flowers con- 

 served in that exquisite perfection which has so advanced our 

 knowledge of cycad structure and growth. They are the 

 structural key to their race, failing which it would not have 

 been possible to decipher even by the more refined methods of 

 fossil imprint and cast study developed in the past few years, 

 either the true floral structure of Williamsonia or the full 

 extent of its cycad ofilicalean relationship. But this great 

 service once rendered, the silicified series wholly fails of the 

 extended interest of the allied casts and imprints, amongst 



