American Fossil Cycads. 247 
Cycadeoid-Angiosperm juxtaposition).” In this last paragraph he 
points out the absence of parallellism in the evolutionary develop¬ 
ment of the mega- and microsporophylls respectively of the 
Cycadeoidese ; for here the microsporophylls have remained primi¬ 
tive, while the female apparatus has become greatly reduced and 
modified ; conversely in the modern Cycas it is the megasporophyll 
which has remained primitive, while the microsporophylls 
have become greatly reduced and changed. Yet the Cycadeoid 
microsporophylls, although of such primitive type in themselves, 
have adopted the cyclic arrangement, which, as the author points 
out, “have made possible a wholly new series of reductions.” He 
proceeds to imagine how from certain Cycadeoid cones with 
spirally-arranged microsporophylls a reduction of these latter to a 
filamentous staminate form might have occurred, giving rise to a type 
of flower like that of Liriodendron. Again “ striking analogies to 
living angiosperms are suggested, no difference whether we fasten 
our attention upon one set of characters, and Liriodendron be 
called to mind, or upon another, with the result that the male and 
female catkins of Amentaceas first suggest themselves, or upon a 
third set that call to mind some other list of characters that must 
have been present in the countless members of a great proangio- 
sperm complex.” “ What right would we have to look for instance 
upon the bifurcate stamens of Ginkgo as separated by an 
unbridgeable hiatus from those of the multibranched stamens of 
Ricinus ? Assuredly none. For the purposes of broader general¬ 
isation, fern-like fronds upon which doubtless were borne the pollen 
of Lyginodendron, the staminate fronds of Cycadeoidea of true 
Marattiaceous type, the mega- and microsporophylls of Cycas, the 
stamens of Cordaites and Ginkgo, and finally of Ricinus and 
Lyg inodcndron, all belong to a series. Nor is there from a plain 
point of view an unbridgable gap between the staminate disk of 
Cycadeoidea or that of Welwitschia, for the latter could arise 
similarly to one of the hypothetical one-seeded and bi-sporangiate 
forms of the Cycadeoidean alliance by one of the simplest of all 
evolutionary processes, viz. increased number of flowers to the plant 
and decrease in bulk, until there was left of each original frond but 
a single filament bearing a pair of pollen-sacs (as in Ginkgo biloba), 
and finally but a single pollen-sac, the filament retaining the 
original cyclic arrangement of the fronds from which they were 
derived.” Finally, he submits that in the Cycadeoidean flower, 
“the juxtaposition of parts is exceedingly suggestive of the pos- 
