Vermont phÅ“nix. [volume] (Brattleboro, Vt.) 1834-1955, 1872-10-04

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environment, these individuals will sur
vive in the struggle for life, and thus the
average character of the species will be
slightly altered. The amount of variation,
thus preserved and enhanced, must in the
course of long ages become enormous. But
these changes directly caused by natural
selection are greatly aided and emphasized
by other changes indirectly produced by
what is called the law of use and disuse,
and by correlation of growth, or internal
equilibration-the effect produced upon
any part of the organism by change in
a related or neighboring part. The disuse
of any physical power or any member,
and the changes in all parts of any animals
frame which would be brought about by a
change in one part caused by natural selec-
tlon, cannot fail to modify the entire struct-
ure, tenn mperament, and mode of life. Even
such q slight change as an increased thick
ness of the woolly coat of mammals may,
by altering the excretory power OF the skin
affect the functions of the lungs, liver and
kidneys, and thus indirectly increase or
diminish the sizo or the animal, which
in turn will modify its speed, its muscular
development, its mental faculties, and its
habits of life.
A SERIES OF DEMON sTRABLE PROPOSITIONS.
1t is sometimes thoughtlessly said that
tho Darwinam theory rests upon purely
gratuitous supposition, and can never be
verified even if it be true. The case is very
different. When analysed, the theory of
natural selection will be found to consist of
eleven propositions, of which nine are de-
demonstrated truths; the tenth is an nev-
liable corollary from its nine predecessors,
and the eleventh is as an admissible postu-
late. Let us enumerate these propositions:
l. Moro organisms perish than survive.
2. No two individuals are exactly alike.
3. Individual peculiarities are transmits
siblo to offspring. 4. individuals whose
peculiarites bring them into closest adap-
tation with their environment arc those
which survive and transmit their peculiar
organizations. 5. The survival of the fit
test thus tends TO maintain an equilibrium
between organisms and their environ
| ments. 6. But the environment of every
group OF organisms is steadily though
slowly changing. 7. Every group of or
ganisms must accordingly change in aver
age character under penalty of extinction.
s. Changes due TO individual variation
arc complicated by the law that change
set up in any one part of highly complex
and coherent aggregate, like an organism,
initiates changes in other parts. 0. They
are further complicated by the law that
structures are nourished in proportion TO
their use. 10. From the foregoing nine
| propositions, each one of which is indispu-
tahly true, it Is an inevitable corrollary
tina; changes thus set up and complicated
must eventually alter the specific character
of any given group of organisms. II. 1t
is postulaed that, since the first appearance
of life upon the earth's surface, sufficient
time has elapsed TO have enabled such
causes as the foregoing TO produce all the
specific heterogeneity now witnessed. The
theory is so strong that no scientific writer
is disposed to deny that the process of ma
tural selection has always gone on and
must continue to go on. And the inference
cannot be avoided that in due course of
time the process must work specific vaiia
tions. The only purely Hypothetical por-
ton of the theory is the assumption that
past geologic time has been long enough to
allow Of the total process of evolution by
such infinitesimal increments. But con-
cerning this assumption it is the clear ver-
diet of logic that, if the theory is thorough
| ly substantiated in all its other portions,
we have the right TO claim as much time as
is needful, provided we do no run counter
to conclusions legitimately reached by as
tronomy, geology, or physics. Now, con-
cerning the age of the earth, neither astron-
omy, nor geology, nor physics has anything
conclusive to say. 1t must be left for fu-
ture inquiries TO give us the quantitative
data requisite for settling this point. Mean
while it must be noted that even the deci-
sion which leaves the smallest time for the
operation of natural selection can weaken
the Darwlnan theory only on the assump-
tion that the agencies alleged by that theory
have been the sole factors concerned in for
wardng organic evolution, and this as
sumption, though it may have been made
by over confident disciples of Mr.. Darwin,
has never been made by Mr.. Darwin him
self He is too profoundly scientific in
| spirit TO imagine that with all his patience
and sa gacity he has solved one of the most
intricate of problems. 1t is quite likely
that further research will disclose other
| agencies which have cooperated with natu-
raj selection in accelerating or retarding
specific evolution.
EXPLANATION OF THE PHENOMENA OF
COLOR.
Among the special phenomena explained
by the theory of natural selection, and
which do not admit of any other scientific
explanation, is that of color in the animal
and vegetable Kingdoms. II used TO be the
vague and untenable (by proof hypothe-
sis that the colors of plants and animals
were duo to the direct action of such phys
ical conditions as climate, soil, or food.
| The explanation by the natural selection
theory is that each species of animals will
be characterized by that shade of color
which is most advantageous TO the spe-
cies in the struggle for existence. Those
animals which need concealment, either
for the sake of protection from others or of
preying upon others, are found TO be near
| ly all so colored as to escape notice, and
those animals which are not protoctivoly
colored are animals whose habits of life
arc such as TO enable them to dispense
with secrecy. The Polar bear is white as
the California bear is gray, and the Hin
doostan bear black, because with a coat
thus colored it can best escape notice and
secure its prey.
The Polar hare has permanent coat of
white; but the Alpine hare, the Artic fox
and the crmine, which do not live amid
| al In, ~.
in the winter only. Such nocturnal ami
mails as owls, bats and moles are dusky
colored. Tue spotted skins of tigers aud
other large cats necessarily tend to blend
with the background of foliage; and out of
many species of tropical tree-snakes, there
is but ono which Is not green. and This