s time, and he
referred to it in these words: "No doubt it is possible, as Mr G.H.
Lewes has urged, that at the first commencement of life many different
forms were evolved; but if so, we may conclude that only a very few
have left modified descendants." ("Origin of Species", page 425.) This
question, though it deserves attention, does not immediately affect the
subject of the palaeontological record of plants, for there can be no
reasonable doubt as to the interrelationship of those groups on which
the record at present throws light.

The past history of plants by no means shows a regular progression from
the simple to the complex, but often the contrary. This apparent anomaly
is due to two causes.

1. The palaeobotanical record is essentially the story of the successive
ascendancy of a series of dominant families, each of which attained
its maximum, in organisation as well as in extent, and then sank into
comparative obscurity, giving place to other families, which under new
conditions were better able to take a leading place. As each family ran
its downward course, either its members underwent an actual reduction in
structure as they became relegated to herbaceous or perhaps aquatic life
(this may have happened with the Horsetails and with Isoetes if derived
from Lepidodendreae), or the higher branches of the family were crowded
out altogether and only the "poor relations" were able to maintain their
position by evading the competition of the ascendant races; this is also
illustrated by the history of the Lycopod phylum. In either case there
would result a lowering of the type of organisation within the group.

2. The course of real progress is often from the complex to the simple.
If, as we shall find some grounds for believing, the Angiosperms came
from a type with a flower resembling in its complexity that of Mesozoic
"Cycads," almost the whole evolution of the flower in the highest
plants has been a process of reduction. The stamen, in particular, has
undoubtedly become extremely simplified during evolution; in the most
primitive known seed-plants it was a highly compound leaf or pinna; its
reduction has gone on in the Conifers and modern Cycads, as well as in
the Angiosperms, though in different ways and to a varying extent.

The seed offers another striking example; the Palaeozoic seeds (if we
leave the seed-like organs of certain Lycopods out of consideration)
were always, so far as we know, highly complex