New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1892-07-17

be traced Immediately in great numbers OF cases
also TO temperature and moisture the later oelhe
so marked that the effects Of long drou'h
in Ncw-Zealand were shown in the paIer hues
of animals. Light also must be considered aS
having an immediate effect on animals For en-
ample, the white underside Of young nouhoers
that lay on mirror in the bottom OF tank De-
gan at once to take on new COLOR upon whioh
The author remarks: "There is obviously no
room here for natural selection" The absence OF
light must also be considered In the case Oh AMI
mails that exist in caves. But as 10 "one
creatures, the theory Of natural selection Is nam
pered by it's own limita lions. By hypothesis. nat
ural selection is concerned only with the ois-
tribution and arrangement Of color. not win us
origin. 1t has therefore nothing to do with the
pigment which forms the basis of color. Now'
even the pigment is missing from cave-aniinais'
and natural selection must be excluded. as hav-
ing had nothing to work upon. On the other
hand, it is excluded from the field Of influence
upon the brilliant coors of deep-sea animals,
where the only light must be that OF the phos-
phorescent inhabitants To the opinion that there
is in the character of this light as related 10
the red, yellow and green coors 80 common
among the creatures of the ocean depths, an eXpa-
nation of the eyes which these animals possessed,
Mr.. Beddard opposes the fact that microscopic
examination has revealed processes OF degeneration
In these deepsea eyes, only TO be explained by
environing darkness. But what is the use OF
bright colors in the midst of profound gloom
Above all, what would be the use of socalled
protective resemblances? Abiding to examples Of
such resemblance on the part of parasites TO
the animal which they infested, the author re-
marks In my own opinion, these cases Of
resemblance are to be explained BY the parasite
actually assimilating and depositing in its own
skin the pigments Of its host but they entirely
parallel TO instances of protective resemblance
among littoral creatures
The point TO the last clause lies in its appli-
cation. If the resemblances of these deep-sea
animals have no protective purpose why should
a protective purpose be assigned for similar
phenomena in the shadows of the sea on land {?
There is always too great tendency to endow
animals with senses exactly similar TO those pos
sessed by ourselves. This tendency is. of course,
more dangerous when we are dealing with the
lower animals There is no proof that even
BIRDS keen-sChted as they are possess anything
comparable TO discriminating human vision. In
the case of dogs. which are naturally more easily
observed. the absence of attention to such minute
notifications as are dwelt on in every treatise
where the theory of natural selection figures, Is
painful TO witness In short. the subject is one
that as yet defeats generalization. Each in
stance Of apparent color resemblance" Mr.
Bcddard says must be discussed on its merits.
The onus probandi lies with those who advocate
the action Of natural selection. The usefulness
/ Of each case Of color resemblance must be dem
onstracd and any facts which tend to prove that
it is of particular have far greater weight
against the theory than suggestions merely based
uopn human ideas of resemblance and difference.
have in its favor" Exactly the same conditions
must be met under the hypothesis of warning
! oo1or t,o+ is oolor IN inf oil ro,Iar
a disagreeable or dangerous animal conspicuous
and under that of protective mimicry. Mr..
Beddard presents tabulatcd statement Of eX-
perimcnts which showed that some prcconccp-
tons on this subject were far from trustworthy.
DR.. Eisig pointed out that in many cases pigment
was identical with eXcrctory matter. Chemical
investigation revealed uric acid in the yellow
color substance of number Of butterflies Upon
such facts Dr. EisiG based opinion that the
pigment itself which produced the supposed
warning color was the true cause OF the disagree
able taste which caused certain insects 10 be re-
ected. This Just reverscs the whole problem. and
makes it likely that The brilliant colors that
is, the abundant secretion OF pigment have
caused the inedblty Of the species. rather than
that the inedibilty has ncccssitated the produc-
| ton Of bright color as advertisement
When it comes to sexual coloration the author
cites Mr.. Wallace who reduced the problem. so
far as female birds were concerned. to Of pro-
lection. that is OF natural selection, and Mr..
StOlzmann. who has done the same for the bril-
| liant colors Of the male birds. His conclu-
sion is in harmony with those reached in respect
to the problems already discussed. we hnd"
says he that the secondary sexual characters
Of animals are dependent upon the germ glands
themselves; and that the sexual diversity OF AMI
mails is also associated with differences Of dsDo-
sition and habit. There is a fundamental diff
ference between males and females based upon the
actual difference Of sex. which generally finds ex
! preston in outward unlikcness. These super
| fetal differences may also be partly due 10 the
different mode OF life led by the two sexes. We
meet with them in animals which cannot be
moved by any choice aesthetic preference;
| but it is also true that they are most highly
| developed in the higher animals. where such
| choice is at least conceivable: the mammal. how
| ever. forms a very important exception TO this
| statement Butterflies and birds show the most
| marked sexual dimorphsm in color; and il is pre-
| cscly in these two groups that there is the
| greatest opportunity for color development. ow-
| ing to the structure OF their feathers and
scales. respectively. Color differences become
necessarily exaggerated In these animals, through
mere multiplication OF details. Nevertheless. it
Is quite possible that sexual selection may have
played a subordinate part in the production Of
sexual coloration."
Besides profusion Of wood cuts the book
contains four colored plates. The beauty OF the
letter-press is marred by cross headings in dark
| print but these are convenient for discovering
| at once any sentence to which one wishes to
rscur.