New-York tribune., 1879-04-15

|
which produceda more economical method of apply
ing the pollen to the pistil would result in saving
of material and thus give the plants in which they
occurred fresh advantage their less fortunate
rivals. Such change is seen in the use OF insect
agency in the fertilization of plants. At an early
period, the stray Towering species which grew
at intervals in a mainly howeress world
must have offered special attractions TO
| insects in the shape of soft, edible, nu-
! tritious pollen. As these insects passed from
! one flower to another, bearing on their legs or
heads the ferilizng powder, they would supply the
plant with more certain means of impresnatlon
than that afforded by the wasteful wind
Hence such plants with their soft pollen and sweet
luices would obtain an extra chance in the struggle
tor life, and hand down the advantage to an ever
| increasing brood of descendants. The most con-
| splcuous difference between wind-fertilized and
insect-fertized blossoms is the difference of color
While the former have seldom more than a few
brownish scales tiny green sepas, the latter as
rnle exhibit large and brilliant petals outside the
essential whorls which attract the eyes of bees or
| butterflies. They have no purpose in tine vegetal
economy than that of alluring the fertilizing
| agents and thus afford strong presumption of de-
veloped coOr-sense the animals for whose
| guidance they have been slowly evolved. We may
| suppose that some of the Towering plants III the
world showed some slight tendency to the at
tractive structures which we now observe III their
completed form. They afforded to insects the soft
and nourishing pollen, and perhaps also small quan-
titles of saccharinc matter The latter, we know Is
| always developed during the opening of flowers at
least in small amounts for the nurture OF the bOs-
som itself. Occasionally individuals might produce
it i'll more than average quantity and so might at
tract than the average share of insect atten-
! tIon In like manner they might have shown
| l,r;o1
their essential organs, and if the eyes of insects
| were capable of Distinguishing these bright coors,
| in no wever imperfect degree the hues would go
| on deepening from generation to generation
| among the plants, while the perception wOuId
| 60 on sharpening from generation to generation
| among the insects. This, however, may be consld-
cred purely an hypothesis and the author then pro-
ceeds to a full statement of the practical grounds
| for the opinion The conclusion lie arrives at is
that there is an original tendency in flowers to the
! the production of colored adJuncts, even prior to
the selectvc action of insects, but that 1t culml-
mated at last in the gorgeous peones, tulips, hles
! and rhOdodendrOns of our modern flower gardens
! The result of his analysis may be summed up IN
brief statement: In the earliest forests of the earth
| green flOwerless vegetation formed the whole race
of plants But as time went on, the earliest
| flowers were produced by some unknown combine
ton. These primeval species were all fertllzcd by
the aid of the wind and possessed no bright corolas
or other cOlOred adjuncts. The aspect of the most
| ancient forest presented sheet of verdure. But
even then there was tendency toward the produc-
| tiOn of red yellow juices, and perhaps of other
colorng matter IN certain portions of the different
| plants As yet, no eve could distinguish them as
| colOrs, but among them certain undeveloped in
sects sought their food. Some of the blossoms thus
| obtained fertilization more easily than be-
| 1,,ol E..raI
! special attractions to the insects were able
| to effect great economy of pollen. Thus
| certain plants came to be always fertilized by
| means of insects From that time those which pos
sessed the greatest quantities of insect food pol
len or honey, most often visited and so most
regularly fertized. Out of this number, moreover
the flowers which displayed their original tendency
to brilliant and distinctive colonization most
likely TO strike the eyes OF insects. Conversely,
whatever insects most readily Disseminated the
dimental patches of color were best able TO secure
their food The production of colored floral whorls,
and the perfecting Of the insect coOr-sense thus
went on progressing side by side. The various
flowers entered into unconscious competition with
one another for the visits of their fertilizers and
those which could especially attract the attention
of a single species, procured mpregnatlon with
greater ease and certainty The colOr-sense of in
sects thus aroused and developed, Is emplOPed for
other purposes, of defence, protection, the chase
after prey the search for mates and similar life
serving actions. Last OF all, the color-sense of in
secs is employed as an aesthetic instrument and the
choice of mates, and thus indirectly produces
through sexual selection, the brilliant hues of but
terflies, beetles, and the other gorgeous insects
which ell the cabinets of the museums.
The effects of the coor-sense in insects on the
familiar aspects of nature described in passage
of rich pOetica eloquence, showing that exactness
Of observation in the case Of the author is easily
blended with aifiuence of Imagination The grand
evidence of an insect COor-sense, he remarks Is to
be found the broad expanse OF meadow and hill
side around us. The million hues of Spring or
Summer flowers have no meaning on any other by
pothesis. The color-sense of bees and butterflies
has transigured the world, and its indications are
found on every plain and mountain of every coun-
try on the EARTH An llustra tion of the fact may
be found in the influence of human action on the
face of nature. Man has produced many changes in
the aspect Of the fauna and flora of every country
which he has brought under his sway. He has cut
down the forests cleared the jungle, reclaimed the
stony waste. His fields glow with golden gram
with mllet barley, oats rice ;swith the vine and
the sugar-cane with the plantain, the banana. the
potatO with flax, and hemp, and cotton His
| orchards are laden with apples, peaches, plums,
pears, oranges, olives, mangOes and papaws.
His meadows are stocked with the clover and
grasses which feed his hOcks and herds. The wild
beasts of the forest have given place to his cattle
his horses his sheep Camels elephants, and
llamas bear his burdens on their patient backs; al
pacas and merinos supply his woven fabrics; silk
worms fatten OH his mulberry trees. But these
changes are as nothing compared with the changes
wrought in the features of nature by the unob
trusive insect Half the fora of the earth bears the
imprint of his likes and his necessities. He has
made the whole Towering creation subservient to
his daily wants. His buttercup, his dandeloD his