New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1870-06-07
NEW PUBLICATIONS.
WALLACE ON NATURAL SELECTION.

sEL WALLACE. Crown Svo. Pr. Ssi. Macmillan W. |
We believe that Mr. Wallacc's right to share with |
Darwin the credit of originating the theory OIL MAUI
raj selection is practically undisputed' both seem
to have been engaged upon the subject al the same
t;me each in ignorance of the researches of the
other Mr. Darwin, by the thoroughness with wmen
he has carried out his Investigations and the SIKH
with which he has set them forth, has secured the
,s,nnlar fame of founder of the scientific creed
but Mr. Wallace has proved that he independently
discovered the same truths and pointed ont thelr I'M
portant application. The present volume contains
his earliest essays the subject with number OF
more recent contributions 10 sclenthc penoucals'
and some additional matter not previously pup
lished We may pass over those papers III whlcli nc
merely anticipates Darwin, though they VIII De
found well worth reading. We purpose TO cali
attention Just now to some very curious naturn
phenomena of which Mr.. Wallace has given so far
as we know the best and fullest account ever pub
Ished These are the phenomena of mimicry and
other protective resombances among animals on
winch valuable essay from his pen was published
in The Westminster ReriGc in 1861. He touched upon
the same subject rather briefly in his excellent Work
on "The Malay Archipelago noticed in these
columns about year ago. Natural mimicIy Is part
of the beautiful provision of nature by which GER
tain dcfenseless animals are endowed with pecuhiu
facilities Of concealment from their enemies, ana
certain
readily seen or recognized by their victims. Desert
animals as a rule are desert cOlored, and the hon
crouching upon the sand must be almost invisible
The birds reptiles and small mammals of the desert
where there are neither trees bTushwOOd nor undl-
latons Of the surface by which they can be concealed
are without exception of the color OF the SOIL AIce
animals are generally white; but in those atudes
where the snow mclts in summer their fur changes
1t that season to some other color because white
would then he the most conspicuous of all Inc
plumagc of the ptarmigan in Summer haImoilzes so
exactly with the lichcncoOred stones among "lhch
il delights 10 sit that a person may walk through
a flock of them without seeing single bird while
in Winter its white plumage is an almost equal pro-
lection A American beetle freQucnts only
one species of tree whose rough bark II so closely
resembles that it is absolutely invisible until 1t
moves Certain small beetles in the East generally
rest ON the mid-rib Of a leaf, where they look so
much like pieces of birds dung that the naturalist
often hesitatoS before picking them of. Two allied
species of butterflies the Kallima inachls OF INDIA
and the Malayan Kallima paTaecta are protected in
a still more wonderful way. The upper surface Of
their wings is very snowy as they are large and
adorned with broad band of rich orange on deep
blue ground The under surface Is variable, no TWO
being found alike but every specimen resembles
some kind Of dead leaf. Not only is the resemblance
perfect in the color. but We find that even the
blotches. mildew, fUngOus growths, and holes Oh
served on dead leaves initiated here with won
derful exactness Now the habits of these insects
are unlike those of other butterflies They frequent
dry forests, and never settle a flower or green
leaf but rest on dead branch. The wings are then
closed together. back 10 back cOncealinQ the head
and antennR. The apex Of the upper wings is pro-
duced into sharp point. The lower wings ter
inmate in a short narrow tail which just touches the
twig upon which the insect is reposinG and presents
every appearance of a stem From the tail to tho
apox runs a dark curved line, like the md-rib of
leaf and from this radiate obque lines represent
ing the lateral veins We thus have "a Disguise
remarks Mr. Wallace, which may be said
TO be absolutely perfect. and the protection
which il affords is sufficiently indicated by
the abundance of the individuals that possess It,"
There are certain insects of the family of Phasmida
or Spectrcs which are called walking-stick insects"
from their singular resemblance to twigs and
branches. Some of these are a foot long and as
thick as ones finger and their whole cOlOTlng, FORM
rugosty and the arrangement of the head legs, and
antenne are such as render them absolutely ident
zeal in appearance with dead sticks. They hang
loosely about shrubs in the forest and have the
traOrduaTy habit of stretching out their legs unsym
metrcay, so 10 render the deception more com
plete One Of these creatures obtained by myself in
Borneo was covered with foliaceOus cXcTeScnces
Of a clear olive green color exactly to resemble
stick grown over by creeping moss or Jungerinan-
MIA" On the principle of natural selection it is easy
to understand how this protective coloring should
be perpetuated. Take the higher animals for in
stance. There is not a single white landbird or
quadruped in Europe except the few alpine or arctic
species TO which white is protective color. Yet in
many of these creatures there seems to be no nher-
ent tendency to avoid white for white varieties a-
pear under dOmesticatiOn and thrive well as the
Others. In a state Of nature the white varieties,
however, would be at a disadvantage in the struggle
for existence white rabbit would be more surely
the prey of hawk or buzzard, and white carnivor-
Gus animal being especially conspicuous would have
more difficulty in pursuing its prey and in time of
scarcity would be apt TO starve 10 death Thus nat
aral selection would gradually exclude all varieties
except those protected by their color.
Far more wonderful, however, than the protection
of color is the phenomenon of mimcry. 1t has long
been known that certain insects bear strange eX-
ternal resemblance to others with which they have
no real affinity whatever but the significance of this
fact has not been understood until lately. II may
now be considered established that in anoverwhelm-
ing majority of cases the animals which resemble
each other have the same habitat, and while one
Uroup is very numerous the other which resembles it
is much less abundant. 1t is generally found land
probably would always be found if our means of OBJ
seryation were more completed that the larger group
has some peculiar means Of defense-either weapon
which its enemies fear, a disagreeable taste or
punpent odor; and the smaller group being without
such defense finds its safety in It's close resemblance
to the group which nature has more formldably
armed. Instances of this mmicTy are most common
among the papihOnida. In the forests OF tropical
South America there is a very abundant family OF
butterflies (Heliconida, characterized by brilliant
L. - Tlat-x v.,ulH cor