insects under the bark of trees; we see them in
the case of the mistletoe, which draws its nourishment
from certain trees, which has seeds that
must be transported by certain birds, and which
has flowers with separate sexes absolutely
requiring the agency of certain insects to bring
pollen from one flower to the other; we see them,
only a little less plainly, in the humblest parasite
which clings to the hairs of a quadruped or the
feathers of a bird; in the structure of the beetle
which dives through the water; in the plumed
seed which is wafted by the gentlest breeze; in
short, we see beautiful adaptations everywhere
and in every part of the organic world.

How, asks Mr. Darwin, to whose theoretical
views we purpose to recur hereafter—how have
all these exquisite adaptations of one part of the
organisation to another part, and to the conditions
of life, and of one distinct organic being
to another, been perfected? He answers, they
are so perfected by what he terms Natural
Selection—the better chance which a better organised
creature has of surviving its fellows—so
termed in order to mark its relation to Man's
power of selection. Man, by selection in the
breeds of his domestic animals and the seedlings
of his horticultural productions, can certainly
effect great results, and can adapt organic beings
to his own uses, through the accumulation of
slight but useful variations given to him by the
hand of Nature. But Natural Selection is a
power incessantly ready for action, and is as
immeasurably superior to man's feeble efforts, as
the works of Nature are to those of Art.
Natural Selection, therefore, according to Mr.
Darwin—not independent creations—is the
method through which the Author of Nature
has elaborated the providential fitness of His
works to themselves and to all surrounding
circumstances.

That creatures so remote in the scale of being
as plants and animals are still bound together by
a web of complex relations, he proves by a curious
illustration. Humble-bees are indispensable to
the fertilisation of the heartsease, for other bees
do not visit that flower. From experiments, he
also found that the visits of bees are necessary
to the fertilisation of some kinds of clover; but
humble-bees alone visit the red clover, as other
bees cannot reach the nectar. Hence he
concludes that if the whole genus of humble-bees
became extinct or very rare in England, the
heartsease and red clover would become very
rare, or wholly disappear. The number of humble-
bees in any district depends in a great degree on
the number of field-mice, which destroy their
combs and nests; and Mr. H. Newman, who has
long attended to the habits of humble-bees,
believes that "more than two-thirds of them are
thus destroyed all over England." Now, the
number of mice is largely dependent, as every
one knows, on the number of cats; and Mr.
Newman says, " Near villages and small towns
I have found the nests of humble-bees more
numerous than elsewhere, which I attribute to the
number of cats that destroy the mice." Hence
it is quite credible that the presence of a feline
animal in large numbers in a district, might
determine, through the intervention, first of mice
and then of bees, the frequency of certain flowers
in that district!

Equally curious, and more difficult to explain,
are what are called representative species. Thus
we have our British song-thrush, which lines its
nest with mud, and which is represented in South
America by a thrush which also lines its nest with
mud, in the same peculiar manner as our own.
This may be called a representation at different
points of space; but species are also represented at
different epochs of time on the same point of space.
Australia, which abounds in kangaroos and other
marsupial animals, also contains abundant relics
of fossil and extinct kangaroos. New Zealand
possesses living wingless birds which are
represented by fossil remains of the wingless birds
of epochs removed from the present by an
unimaginable distance of time.

For, of the elaboration of species as maintained
by Mr. Darwin, not the least overwhelming idea
is the lapse of time which it has occupied to
accomplish. Some species have retained the
same specific form for very long periods—
enormously long as measured by years. The lapse of
time has been so great as to be utterly inappreciable
by the human intellect. The mind cannot
possibly grasp the full meaning of the term of a
hundred million years; and therefore it has a
difficulty in adding up and perceiving the full
effects of many slight variations, accumulated
during an almost infinite number of generations.
The belief that species were immutable productions,
was almost unavoidable, as long as the
history of the world was thought to be of short
duration. From geology we have now acquired
some idea of the lapse of time. During the
early periods of the earth's history, when the
forms of life were probably few and simple,
the rate of change was probably slow; at the
first dawn of life, when very few forms of the
simplest structure existed, the rate of change
may have been slow in an extreme degree. The
whole history of the world, as at present known,
although of a length quite incomprehensible to
us, will hereafter be recognised as a mere fragment
of time, compared with the ages which
have elapsed since the first creature, the
progenitor of innumerable extinct and living descendants,
was created.

From the imperfect and contradictory way in
which the past history of the species of organised
life on our planet has been interpreted, some
notion may be formed of the difficulty of anticipating
the future. All that we can with safety
presume is, that changes among the living tenants
of the earth, equally important in respect to
forms and habits with those which have already
occurred, are probable in times to come. Some
writers believe that man has, at last, "begun to
reap the fruits of his tedious education, and has
proved to how great a degree 'knowledge is