W. T. Saxtoil. 
^56 
basal forms the embryo initial, and the next the suspensor; 
male and female nuclei equal in size at the time of ferti¬ 
lization. ...... Cupressacece : Sequo'idece. 
V. Archegonia as in II and III; male gametophyte without 
prothallial cells; male cells very unequal; pro-embryo somewhat 
variable, forming from four to thirty-two free nuclei before wall- 
formation, nearly or quite filling the archegonium; in one genus the 
terminal tier forms a protective cap, as in Araucariaceae, otherwise 
the mature pro-embryo is similar to that of Podocarpaceae, with the 
exception that the single embryo initial is uninucleate, not 
binucleate. ........ Taxacece. 
V.— Phylogeny of Comferales. 
While the present state of our knowledge of the Coniferales 
seems to lead quite naturally to a classification more or less on the 
lines here suggested, there is much greater difficulty in trying to 
fit the known characters of the genera into any satisfactory scheme 
of phylogeny. It may be taken as a starting point that the Conifers 
are monophyletic, an opinion evidently held by the very large 
majority of the recent workers on the group. Each of the families 
is clearly related, either directly or through a third family, with 
each of the others. Thus the male gametophyte of Araucariaceae, 
Podocarpaceae and Abietoideae indicates a common ancestry for the 
first three families; the archegonia and pro-embryo of Podo- 
carpaceae and Taxaceae indicates for these two a common, though 
perhaps more remote, origin ; while Sciadopitys is clearly a con¬ 
necting link between Abietoideae on the one hand and Cupressoideae 
on the other (though much more nearly related to the former), thus 
connecting the Cupressaceae with the Pinaceae. 
To the writer it seems altogether inconceivable that any of the 
Gymnosperms can have been derived from Lycopod ancestors. Both 
gametophytes in the Cycads, Ginkgo, and the Coniferales point to 
the conclusion that these three phyla originated from the same 
plexus, and, thanks to recent palaeobotanical research, there is every 
reason for believing that this plexus was fern-like in origin, and not 
derived from the palaeozoic Lycopods. As far as the Cycads are 
concerned, such a view appeal’s to have been quite definitely 
accepted, and on the whole the case for the derivation of Conifers 
and Ginkgoales, through or near the Cordaitales, from a similar 
origin, seems equally strong. 
l'he best case for the opposite view has recently been stated 
by Mr. Stiles, his chief argument against the Cordaitalean origin 
being that, because the Podocarps differ rather widely from the 
