82 FLANT REMAINS IN NORTH AMERICA. 
extensive, known to have an abhorrence of self-fertilization. It may 
not be out of place to hazard a reason for this course : 
There would seem to be two distinct principles in relation to form 
going along together with the life of a species. The tendency of the 
one force is to preserve the existing form; the other to modify, and 
extend it to newer channels. The first we represent by the term în- 
heritance, the other we understand as variation. Inheritance struggles 
io have the plant fertilize itself with its own pollen; whilst the efforts 
of variation are towards an intermixture of races or even neighbouring 
individuals, rather than with members of the one brood or family. 
May it not be possible that at some time in their past history all spe- 
cies of plants have been hermaphrodite? that Diccism is a later tri- 
umph of variation, its final vietory in the struggle with inheritance? 
There are some difficulties in the way of such a theory, as there are 
with most of these theories; but it seems clear from this case of Epigea 
that cultivation has not as much to do with changes as it gets credit 
for, and we may readily believe that, independently of external circum- 
stances, there is a period of youth and a period of old age in form as 
well as in substance, and that we may therefore look for a continual 
creation of new forms by a process of vital development, just as ra- 
tionally aud as reverently as for the continued succession of new indi- 
viduals. 
The discovery of dicecism in Zpigea is interesting from the fact that 
it is probably the first instance known in true Zricaceg. In the Eri- 
eal suborder of Francoacee, abortive stamens are characteristic of the 
family, and in the Pyrolacee antherless filaments have been recorded.— 
Meehan’s Gardener's Monthly, February, 1869 
ON THE PLANT REMAINS FOUND IN THE CRETACEOUS 
AND TERTIARY STRATA OF NORTH AMERICA. 
The Cretaceous flora of Britain, and indeed of Europe, presents an 
assemblage of plants very different from those which succeeded them 
in the same area, either in ‘Tertiary or recent times. The fruits of 
Pandanee, arborescent Liliacee, several genera of Cycadee, species of 
Araucaria and Sequoia, with numerous Ferns and gigantic Eguiseta, 
are.found in the Cretacecus beds of Britain. M. Coemans has de- 
