275 



■were members of the Bennettitese, and did not conform in the 

 characters of their reproductive organs to the existing members 

 of the Cycadacese. 



Is it possible, therefore, that Beania gracilis may have belonged 

 to Ginkgo or some other member of the Ginkgoacese? We are 

 familiar with male flowers in the Yorkshire rocks which agree 

 with those of the maidenhair-tree, and in all probability were borne 

 by species of Ginkgo, but as yet we have no evidence of the 

 existence in Britain of female flowers of the modem Ginkgo type. 

 Heer has described a few fragments from the Arctic regions, 

 recalling the female flowers of Ginkgo hilola, but no satisfactory 

 specimens are known. There is, indeed, a considerable difference 

 between Beania gracilis and the female flowers of Ginkgo as they 

 ■exist at the present day, but it is conceivable that the Mesozoic 

 representatives of this genus, which exhibits so many points of 

 <!ontact with the Cycads, may have possessed reproductive organs 

 more nearly related to those of recent Cycads than is the case with 

 "the surviving species. The male flowers of both fossil and recent 

 Ginkgos consist of a central axis, bearing loosely disposed stamens, 

 and are constructed on the same plan as Beania gracilis. The usual 

 and normal female flowers of Ginkgo biloha consist of a strong axis 

 bearing two terminal sessile ovules, but it is not uncommon to find 

 examples in which the main axis bears several ovules, irregularly 

 arranged and separated by fairly long internodes, borne on slender 

 pedicels inclined at a considerable angle to the stouter central axis. 

 Such abnormal flowers are of importance as at least showing 

 a possible variation in the structure of the female reproductive 

 shoot, and they afford a nearer approach to the type represented 

 by Beania. The agreement is by no means perfect ; in the Ginkgo 

 £owers the ovules are terminal, and the apex points outwards, while 

 in Beania they are attached to the inner side of a peltate expansion 

 of the carpophyll. But this is a difference insufficient to invalidate 

 a comparison. If we imagine the ovules of Ginkgo turned through 

 an angle of 180° we should have the collar-like envelope occupying 

 the same position as the peltate expansion in Beania. Some of the 

 abnormal flowers of Ginkgo, such as those figured by Fujii ' and one 

 recently figured by Miss Gowan and myself, approach more closely 



Fujii (96). 



