i43 
Tree (Ginkgo hiloha , L.). 
the Jurassic plant-beds of Siberia, Heer has found several 
specimens of male flowers which agree very closely with 
those of the recent species. From a central axis numerous 
loosely disposed stamens are given off at a wide angle, and 
the filaments bear two or sometimes three or more terminal 
pollen-sacs 1 . The specimen shown in Fig. 28, PI. IX, some¬ 
what enlarged, represents an imperfect specimen of a male 
flower from the Inferior Oolite beds of Yorkshire; it is less 
perfect than the Siberian examples, but of interest as the 
best so far recognized from an English locality. There is 
a striking similarity as regards the external form between 
the fossil and recent type of flower. A few isolated pollen- 
sacs of Ginkgo were figured by Phillips 2 in 1829 as 
‘ unknown leaves 5 ; the true nature of the fossil shown in 
Fig. 28 being first suggested by Nathorst. 
The flowers associated with Baiera leaves and described 
by Schenk and other authors are similar to those of Ginkgo , 
but differ in the greater number of pollen-sacs borne on 
each stamen 3 . 
As regards the female flowers the evidence is somewhat 
less conclusive. Heer has figured several fossil seeds and 
portions of peduncles which he refers on fairly good grounds 
to the genus Ginkgo , but for the most part the seeds occur as 
detached bodies, and throw little light on the nature of the 
female flowers of the Jurassic species of the Ginkgoaceae. 
The most interesting fossil from our present point of view is 
one which Carruthers described in 1869 under the name 
Beania gracilis 4 ; in general structure this species is very 
similar to a female flower of the Cycad Zamia , in which 
the individual carpophylls are farther apart than in the recent 
type of cone. If we imagine the internodes of a Zamia flower 
considerably elongated, we have an arrangement closely 
resembling Beania. The central axis, which is fairly short 
and woody, bears loosely disposed secondary axes attached at 
right angles ; these branches are probably carpophylls, and each 
1 Heer (’68-85), passim. 2 Phillips (’29), PL VII, Fig. 23 . 
3 Schenk (’67). 4 Carruthers (’69). 
