urprised
if in its stead you find the box tenanted by a swarm of little black
flies--an impish-looking crew. Whence came all these? Why they and the
empty chrysalis shell are all that remains of your cherished prize; so look
no more for the fair sunny butterfly, devoured ere born by that
ill-favoured troop of darklings who have just now issued from the lifeless
shell.

The truth is, that long since, perhaps in early larva-hood, the creature's
fate was sealed; a deadly enemy to his race is ever on the alert, winging
about in the shape of a small black fly, in search of an exposed and
defenceless caterpillar. Having selected her victim, she pierces his body
with a sharp cutting instrument she is armed with, and in the wound
deposits an egg; the {19} caterpillar winces a little at this treatment,
but seems to attach little importance to it. Meanwhile his enemy repeats
her thrusts till some thirty or forty eggs, germs of the destroyers, are
safely lodged in his body, and his doom is certain beyond hope. The eggs
quickly hatch into grubs, who begin to gnaw away at the unhappy creature's
flesh, thus reducing him gradually, but by a profound instinct keeping
clear of all the vital organs, as if knowing full well that the creature
must keep on feeding and digesting too, or their own supply would speedily
fail; as usurers, while draining a client, keep up his credit with the
world as long as they can.

Weaker grows the caterpillar as the gnawing worms within grow stronger and
nearer maturity. Sometimes he dies a caterpillar, sometimes he has strength
left to take the chrysalis shape, but out of this he _never_ comes a
butterfly--the consuming grubs now finish vitals and all, turn to pupae in
his empty skin, and come out soon, black flies like their parent.

But, supposing that it has escaped this great danger, we now see the
creature in its completest form, as the

IMAGO, OR PERFECT BUTTERFLY.

The first term, _Imago_, is a Latin one, merely signifying an image, or
distinct unveiled form; as distinguished from the previous _larva_, or
masked state, and the _pupa_, or swathed and enveloped state. The word
_imago_ then, in works on entomology, always means the {20} perfect and
last stage of insect life, and is applied to all insects with wings--for it
must be borne in mind that no insect is ever winged till it reaches the
last stage of its existence.

If the progressive development of these lovely beings is so marvellous, no