The Nymphalidae Are A Very Extensive Group, Of Generally
Strong-Winged And Very Bright-Coloured Butterflies, Very Abundant
In The Tropics, And Represented In Our Own Country By Our
Fritillaries, Our Vanessas, And Our Purple-Emperor.
Some months
ago I drew up a list of the Eastern species of this group,
including all the new ones discovered by myself, and arrived at
the following comparative results:
-
Species of Species peculiar to Percentage
Nymphalidae. each island. of peculiar Species.
The Coleoptera are so extensive that few of the groups have yet
been carefully worked out. I will therefore refer to one only,
which I have myself recently studied - the Cetoniadae or Rose-
chafers - a group of beetles which, owing to their extreme
beauty, have been much sought after. From Java 37 species of
these insects are known, and from Celebes only 30; yet only 13,
or 35 percent, are peculiar to the former island, and 19, or 63
percent, to the latter.
The result of these comparisons is, that although Celebes is a
single, large island with only a few smaller ones closely grouped
around it, we must really consider it as forming one of the great
divisions of the Archipelago, equal in rank and importance to the
whole of the Moluccan or Philippine groups, to the Papuan
islands, or to the Indo-Malay islands (Java, Sumatra, Borneo, and
the Malay peninsula). Taking those families of insects and birds
which are best known, the following table shows the comparison of
Celebes with the other groups of islands: -
PAPILIONIDAE AND HAWKS, PARROTS, AND
PERIDAE PIGEONS.
Percent of peculiar Percent of peculiar
Species. Species.
Indo-Malay region . . . . 56 . . . . . . . . . . 54
Philippine group . . . . 66 . . . . . . . . . . 73
Celebes . . . . . . . . . 69 . . . . . . . . . . 60
Moluccan group . . . . . 52 . . . . . . . . . . 62
Timor group . . . . . . . 42 . . . . . . . . . . 47
Papuan group . . . . . . 64 . . . . . . . . . . 74
These large and well-known families well represent the general
character of the zoology of Celebes; and they show that this
island is really one of the most isolated portions of the
Archipelago, although situated in its very centre.
But the insects of Celebes present us with other phenomena more
curious and more difficult to explain than their striking
individuality. The butterflies of that island are in many cases
characterised by a peculiarity of outline, which distinguishes
them at a glance from those of any other part of the world. It is
most strongly manifested in the Papilios and the Pieridae, and
consists in the forewings being either strongly curved or
abruptly bent near the base, or in the extremity being elongated
and often somewhat hooked. Out of the 14 species of Papilio in
Celebes, 13 exhibit this peculiarity in a greater or less degree,
when compared with the most nearly allied species of the
surrounding islands. Ten species of Pieridae have the same
character, and in four or five of the Nymphalidae it is also very
distinctly marked. In almost every case, the species found in
Celebes are much larger than thane of the islands westward, and
at least equal to those of the Moluccas, or even larger. The
difference of form is, however, the most remarkable feature, as it
is altogether a new thing for a whole set of species in one
country to differ in exactly the same way from the corresponding
sets in all the surrounding countries; and it is so well marked,
that without looking at the details of colouring, most Celebes
Papilios and many Pieridae, can be at once distinguished from
those of other islands by their form alone.
The outside figure of each pair here given, shows the exact size
and form of the fore-wing in a butterfly of Celebes, while the
inner one represents the most closely allied species from one of
the adjacent islands. Figure 1 shows the strongly curved margin
of the Celebes species, Papilio gigon, compared with the much
straighter margin of Papilio demolion from Singapore and Java.
Figure 2 shows the abrupt bend over the base of the wing in
Papilio miletus of Celebes, compared with the slight curvature in
the common Papilio sarpedon, which has almost exactly the same
form from India to New Guinea and Australia. Figure 3 shows the
elongated wing of Tachyris zarinda, a native of Celebes, compared
with the much shorter wing of Tachyris nero, a very closely
allied species found in all the western islands. The difference
of form is in each case sufficiently obvious, but when the
insects themselves are compared, it is much more striking than in
these partial outlines.
From the analogy of birds, we should suppose that the pointed
wing gave increased rapidity of flight, since it is a character
of terns, swallows, falcons, and of the swift-flying pigeons. A
short and rounded wing, on the other hand, always accompanies a
more feeble or more laborious flight, and one much less under
command. We might suppose, therefore, that the butterflies which
possess this peculiar form were better able to escape pursuit.
But there seems no unusual abundance of insectivorous birds to
render this necessary; and as we cannot believe that such a
curious peculiarity is without meaning, it seems probable that it
is the result of a former condition of things, when the island
possessed a much richer fauna, the relics of which we see in the
isolated birds and Mammalia now inhabiting it; and when the
abundance of insectivorous creatures rendered some unusual means
of escape a necessity for the large-winged and showy butterflies.
It is some confirmation of this view, that neither the very small
nor the very obscurely coloured groups of butterflies have
elongated wings, nor is any modification perceptible in those
strong-winged groups which already possess great strength and
rapidity of flight. These were already sufficiently protected
from their enemies, and did not require increased power of
escaping from them. It is not at all clear what effect the
peculiar curvature of the wings has in modifying flight.
Another curious feature in the zoology of Celebes is also worthy
of attention.
Enter page number
PreviousNext
Page 104 of 112
Words from 105208 to 106215
of 114260
