In a new nest the belt of exit-doors is coated with a material that seems different from the rest—a layer of fine porous matter, of a pure, dull, almost chalky white, which contrasts with the dirty white of the remainder of the nest. It is like the mixture that confectioners make of whipped white of egg, sugar, and starch, with which to ornament their cakes. This snowy covering is very easily crumbled and removed. When it is gone the exit-belt is clearly visible, with its two rows of plates. The wind and rain sooner or later remove it in strips or flakes, and therefore the old nests show no traces of it.
But these two materials, though they appear different, are really only two forms of the same matter. The Mantis with her ladles sweeps the surface of the foam, skimming the top of the froth, and collecting it into a band along the back of the nest. The ribbon that looks like sugar-icing is merely the thinnest and lightest portion of the sticky spray, which appears whiter than the nest because its bubbles are more delicate, and reflect more light.
It is truly a wonderful piece of machinery that can, so methodically and swiftly, produce the horny central substance on which the first eggs are laid, the eggs themselves, [[48]]the protecting froth, the soft sugar-like covering of the doorways, and at the same time can build overlapping plates, and the narrow passages leading to them! Yet the Mantis, while she is doing all this, hangs motionless on the foundation of the nest. She gives not a glance at the building that is rising behind her. Her legs act no part in the affair. The machinery works by itself.
As soon as she has done her work the mother withdraws. I expected to see her return and show some tender feeling for the cradle of her family, but it evidently has no further interest for her.
The Mantis, I fear, has no heart. She eats her husband, and deserts her children.
III
THE HATCHING OF HER EGGS
The eggs of the Mantis usually hatch in bright sunshine, at about ten o’clock on a mid-June morning.
As I have already told you, there is only one part of the nest from which the grub can find an outlet, namely the band of scales round the middle. From under each of these scales one sees slowly appearing a blunt, transparent lump, followed by two large black specks, which are the creature’s eyes. The baby grub slips gently [[49]]under the thin plate and half releases itself. It is reddish yellow, and has a thick, swollen head. Under its outer skin it is quite easy to distinguish the large black eyes, the mouth flattened against the chest, the legs plastered to the body from front to back. With the exception of these legs the whole thing reminds one somewhat of the first state of the Cicada on leaving the egg.