showy—it was resting in some numbers on the still
leafless branches of a solitary acacia on the bare veld.
Being far beyond our reach we threw large pieces of
quartzite against the branches, and the concussion, as
a rule, brought the insects to the ground, when they
were secured before they could take wing. This species
was always found on the branches of an acacia. Beetles
are, however, difficult to obtain; they are plentiful for
a short time at the commencement of the rains, then
become scarcer as the summer season advances, and are
almost totally absent during the long dry season.
Although the hedges were a mass of roses constantly in
bloom during the summer, I was surprised to see how
little they were visited by floral beetles. Certainly
myriads of the Cetoniid Pachnoda flaviventris could
generally be seen, and also the large Cantharid Mylabris
ophthalmica, but the majority of all these flower-visiting
Coleóptera confined themselves to the small and obscure
bloom found on the veld. A new tree would burst into
bloom, its flowers lasting but a short time, during which
frequently a species of the Cetoniidae not hitherto seen
would visit in quantity this fugitive blossom and again
quickly disappear with it.
From long observation in the field and of the contents
in my cabinets at home, I had become convinced of the
phenomena and the truth of the theory of mimicry* in
the insect world, by which under the law of natural selection
edible species showing any resemblance to inedible
ones, have gradually been preserved by the protection
thus afforded, and the same selective process going on
among their progeny for long periods of time has resulted
in those wonderful resemblances which we now
find among distinct orders of insects. So strongly was
this always in my mind that I frequently was stung by
real Hymenoptera, when I expected too much and
thought I might be handling an imitator. But the
tables were quite turned when I first captured a female
of the longicorn Amphidesmus analis, which on a leaf
has a surprising resemblance to a female of the genus
* Long since enunciated and proved by my friend Mr. H. W. Bates.
Lycus belonging to a totally different Coleopterous
family, and I was completely deceived till I held the
insect in my hand. The objections urged against the
theory of mimicry are generally based on a total misunderstanding
of the theory itself. One frequently
listens to arguments against a hypothetical assumption
that an insect of its own volition, for protective purposes,
copies the garb and appearance of an inedible
species. Such a wild proposition would require no
objection, for it could obtain no support. I t is only
when one has realized the struggle for existence in all
animal life—including man himself,—-has recognized
the unbending, inexorable, and universal application of
natural laws, appreciated that benevolence is an acquired
product of the human heart and not of natural
life, and observed that all life exists in an iron-bound
environment, where strength reigns supreme and the
strong taketh by force—it is only then one understands
what Herbert Spencer has so well called the
“ survival of the fittest,” and what Darwin had enabled
him thus to see by his enunciation of “ Natural Selection.”
With these facts before us we can comprehend
how this “ breed ” of the persecuted beetle, ever tending
by the attacks of its enemies—a form of natural selection—
to perpetuate its race by its more favoured representatives
who were mistaken for inedible species, in
the course of time reached—in scanty numbers, it may
be—its zenith in simulative appearance and escaped
extinction. These mimicking species are the shadow of
a past, when there was a great need and a great
danger.