212 The Palaeontological Record. IT. Plants 
far more advanced than the Pteridospermeae, and in many respects 
approaching the Coniferae, which themselves begin to appear in the 
latest Palaeozoic rocks. The Cordaiteae, while wholly different in 
habit from the contemporary fern-like Seed-plants, show unmis- 
takable signs of a common origin with them. Not only is there 
a whole series of forms connecting the anatomical structure of the 
Cordaiteae with that of the Lyginodendreae among Pteridosperms, 
but a still more important point is that the seeds of the Cordaiteae, 
which have long been known, are of the same Cycadean type as those 
of the Pteridosperms, so that it is not always possible, as yet, to 
discriminate between the seeds of the two groups. These facts 
indicate that the same fern-like stock which gave rise to the Cycado- 
phyta and through them, as appears probable, to the Angiosperms, 
was also the source of the Cordaiteae, which in their turn show 
manifest affinity with some at least of the Coniferae. Unless the 
latter are an artificial group, a view which does not commend itself 
to the writer, it would appear probable that the Gymmnosperms 
generally, as well as the Angiosperms, were derived from an ancient 
race of Cryptogams, most nearly related to the Ferns? 
It may be mentioned here that the small gymnospermous 
group Gnetales (including the extraordinary West African plant 
Welwitschia) which were formerly regarded by some authorities 
as akin to the Equisetales, have recently been referred, on better 
grounds, to a common origin with the Angiosperms, from the 
Mesozoic Cycadophyta. 
The tendency, therefore, of modern work on the palaeontological 
record of the Seed-plants has been to exalt the importance of the 
Fern-phylum, which, on present evidence, appears to be that from 
which the great majority, possibly the whole, of the Spermophyta 
have been derived. 
One word of caution, however, is necessary. The Seed-plants 
are of enormous antiquity ; both the Pteridosperms and the more 
highly organised family Cordaiteae, go back as far in geological 
history (namely to the Devonian) as the Ferns themselves or any 
other Vascular Cryptogams. It must therefore be understood that 
in speaking of the derivation of the Spermophyta from the Fern- 
phylum, we refer to that phylum at a very early stage, probably 
earlier than the most ancient period to which our record of land- 
plants extends. The affinity between the oldest Seed-plants and the 
Ferns, in the widest sense, seems established, but the common stock 
from which they actually arose is still unknown ; though no doubt 
1 Some botanists, however, believe that the Coniferae, or some of them, are probably 
more nearly related to the Lycopods. See Seward and Ford, “The Araucarieae, Recent 
and Extinct,” Phil. Trans. Royal Soc. Vol. 198, 8, 1906. 
