e window and persists in
avoiding the trap of the revolving cardboard.

The track is only a short one: the cardboard measures three hand's
breadths in length. Let us give more space. I settle the grubs on the
floor of the room; with a hair pencil, I turn them with their heads
pointing towards the lighted aperture. The moment they are free, they
turn and run from the light. With all the speed whereof their cripple's
shuffle allows, they cover the tiled floor of the study and go and knock
their heads against the wall, twelve feet off, skirting it afterwards,
some to the right and some to the left. They never feel far enough away
from that hateful illuminated opening.

What they are escaping from is evidently the light, for, if I make it
dark with a screen, the troop does not change its direction when I turn
the cardboard. It then progresses quite readily towards the window; but,
when I remove the screen, it turns tail at once.

That a grub destined to live in the darkness, under the shelter of a
corpse, should avoid the light is only natural; the strange part is its
very perception. The maggot is blind. Its pointed fore part, which
we hesitate to call a head, bears absolutely no trace of any optical
apparatus; and the same with every other part of the body. There is
nothing but one bare, smooth, white skin. And this sightless creature,
deprived of any special nervous points served by ocular power, is
extremely sensitive to the light. Its whole skin is a sort of retina,
incapable of seeing, of course, but able, at any rate, to distinguish
between light and darkness. Under the direct rays of a searching sun,
the grub's distress could be easily explained. We ourselves; with our
coarse skin, in comparison with that of the maggot, can distinguish
between sunshine and shadow without the help of the eyes. But, in the
present case, the problem becomes singularly complicated. The subjects
of my experiment receive only the diffused light of the sky, entering my
study through an open window; yet this tempered light frightens them out
of their senses. They flee the painful apparition; they are bent upon
escaping at all costs.

Now what do the fugitives feel? Are they physically hurt by the chemical
radiations? Are they exasperated by other radiations, known or unknown?
Light still keeps many a secret hidden from us and perhaps our optical
science, by studying the maggot, might become the richer by some
valuable information. I wou