New-York daily tribune. [volume] (New-York [N.Y.]) 1842-1866, 1860-02-11

and tumbles, with those breeds as now existing IN
Britain, India and Persia we can readily trace tne
stsges through which they have inSensiby passed.
and come to differ so greatly from the rock Pls0Ou'
In plants the same gradual process OF improve
ment through the occasional preservation Vi VIC
best individuals may be recognized in the increased
size and beauty now to be seen in the Varleuos VI
the heartsesse rose, peArgOnium, danna' anu o'uor
plants when compared with the Older varieties or
,isb their parent stocks No one expects to obtain
fr.t.rate beartsease or dAhlia from the seed OF
wild plapt. or a frst-rate melting pear from the
seed of the wild pear. This fruit, though cultivated
in classical times, appears to have been Of very in
ferior quality Great surprise is often expressed at
the skill of gardeners in having produced such
splendid results from such poor materials. But the
art has been simple and, as far as the final result is
concerned, has been followed almost unconsciOusly.
II has consisted in always oultvstiug the best
known variety, sowing its seeds, and when slight
y better variety has CHANGED to appear, selecting it
and 90 onward. The gardeners Of the classical
period who cultivated the beet pear they could pro-
cure, never thought what splendid fruit would DO
enjoyed at this remote day, though it is due, in
some degree OF least, to their having naturally
chosen and preserved the best varieties they could
find.
The application Of these principles to organic
beings in state of nature is not difficult No one
suppOses that all the individuals of the same sPe-
cies are cast in the very same mold. But the ind-
ydual differences such as are known frequently TO
appear in the offspring from the same parents,
afford materials for natural selection to accumulate
in the same manner as man can artihcially accumu-
late individual differences in bis domesticated pro-
auctions. It is mistake Of naturalsts to suppose
that important organs never vary. The varieties,
in fact are so great, that in the AOras Of special
countries drawn up by different botAnists, surpris-
ing number Of forms have been ranked by one
bOtanist as genuine species and BY another as mere
varieties. The same is true of the animals 10 diff
ferent aresS Many of the BIRDS and insects in
North America and in Europe which differ very
slightly from each other, have been ranked by one
eminent naturalist as undOubted species, and by
another 90 varieties, err as they are often called
geographical races. The term species, accordingly,
is reg Arded by Mr. Darwin one arbitrarily given
closely resembling each other, and not essentially
differing from the term variety, which is given to
less distinct and more auctuating forms. The term
variety again, in comparison with mere individual
differences, is also applied arbitrarily and for the
sake Of convenience.
We are now prepared TO advance another step,
and TO approach the question as to the origin Of
species in nature. How have the exquisite adaptA-
tons OF one part Of the organization to another
part, and to the conditions Of life aud Of one dis
tinct organic being to another being, beed perfect
ed? These beautiful adaptations are in every part
Of the organic world. Wesee them in the relations
Of the WOOdpecker and mistletoe; in the humbless
parasite which clngs to the hairs Of qusdruped or
the feathers Of bird; in the plumed seed which is
waited by the gentlest breeze. How is 1t, again,
that minute varieties become ultimately converted
into distinct Species which in most cases obviously
differ from each other far more than do the vari-
cites of the same speciesl All these results-and
here is a cardinal point in Mr.. Darwin's theory
follow inevitably from the struggle for life. Owing
to this struggle any variation, however slight if it
be in any degree profitable to an individual Of any
species, in its infinitely complex relations to other
organic beings and TO external nature, will tend TO
the preservation Of that individual, and will gen.
orally be inherited by its offspring. The offspring,
also, will thus have better chance Of surviving,
foy Of the many individuals Of any species which
are periodically born but small number can sur
viye. This principle bywhch each slight variation,
if usefa is preserved is called by the author nstu
A.. L -. b -
power Of selection. Man by selection can certainly
produce 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 s power inces-
santly ready for action, and is far superior to
mans feeble Efforts as the works of nature are
superior 10 those Of srt.
The struggle for existence, which is at the fOun-
dation Of the principle Of natural selection in
cIudes not only the life of the individual, but
success in leaving progeny. Two canine animals
in q time Of dearth may be truly said to struggle
with each other which shall get food and i've But
the term is used in larger sense. A plant on the
edge of desert is said to struggle for life against
the drOath; but plant which annually produces
thousand seeds, Of which on an average only one
comes TO maturity, may more truly be said to
struggle with the plants of the same and other
kinds which already elOthe the ground. struggle
for existence inevitably follows from the high rate
at which al organic beings tend to increase. Every
being, which during its natural lifetime produces
several seeds eggs must suffer destruction during
some period Of its life, and during some season or