ONOCLEA SENSIBILIS. 
SENSITIVE FERN. 
NATURAL ORDER, FILICES. 
ONOCLEA SENSIBILIS, Linnzeus.—Sterile fronds oblong-triangular; pinnz lanceolate,—the lower 
ones distinct, pinnatifid-dentate,—the upper confluent, repand-dentate, or entire. Sterile 
frond six to fifteen inches long, and five to twelve inches wide at the base; lower pinnze 
three to six inches long; stipe six to ten inches long, slender, angular, naked. Fertile 
fronds four to eight or ten inches long; pinnz one to three inches long, nearly erect; pin- 
nules triangular-globose, smoothish, dark brown, resembling berries in two-rowed unilat- 
eral spikes; stipes eight to twelve inches long, rather stout, terete, naked. (Darlington’s 
Flora Cestrica. See also Gray’s Flora of the Northern United States, Chapman’s Flora 
of the Southern United States, Wood's Class-Book of Botany, and Williamson’s Ferns of 
Kentucky.) 
#§OST intelligent persons know that according to the mod- 
ern discoveries in geology, plants existed on the earth 
ages before man made his appearance thereon; and that in 
regard to the plants themselves, numerous races have lived 
and died of which we know nothing now beyond a few traces 
here and there of a few species which have been preserved to us 
in the shape of fossil remains. As to the manner of the appear- 
ance and disappearance of these races, as the ages followed each 
other in due course, there are differences of opinion. Some 
believe that the newer forms have been evolved from the older 
ones by slow and almost imperceptible degrees. We find, in 
our time, by closely watching seedling plants, that no two are 
exact reproductions of their parents, or exactly like each other; 
and if we are not disposed to think that these variations revolve 
in a circle, but are continuously in a direct line, it will not be dif- 
ficult to believe that the accumulation of small differences may 
in time present a structure very different from what we may 
imagine the first parent to have been. In this way those who 
(17) 
