We have just seen the insect turn head uppermost. This reversal causes the wings and elytra to fall into their natural position. Extremely flexible, and yielding to their own weight, they had previously drooped backwards with their free extremities pointing towards the head of the insect as it hung reversed.
Now, still by reason of their own weight, their position is rectified and they point in the normal direction. They are no longer curved like the petals of a flower; they no longer point the wrong way; but they retain the same miserable aspect.
In its perfect state the wing is like a fan. A radiating bundle of strong nervures runs through it in the direction of its length and forms the framework of the fan, which is readily furled and unfurled. The intervals are crossed by innumerable cross-nervures of slighter substance, which make of the whole a network of rectangular meshes. The elytrum, which is heavier and much less extensive, repeats this structure.
At present nothing of this mesh-work is visible. Nothing can be seen but a few wrinkles, a few flexuous furrows, which announce that the stumps are bundles of tissue cunningly folded and reduced to the smallest possible volume.
The expansion of the wing begins near the shoulder. Where nothing precise could be distinguished at the outset we soon perceive a diaphanous surface subdivided into meshes of beautiful precision.
Little by little, with a deliberation that escapes the magnifier, this area increases its bounds, at the expense of the shapeless bundle at the end of the wing. In vain I let my eyes rest on the spot where the expanding network meets the still shapeless bundle; I can distinguish nothing. But wait a little, and the fine-meshed tissues will appear with perfect distinctness.
To judge from this first examination, one would guess that an organisable fluid is rapidly congealing into a network of nervures; one seems to be watching a process of crystallisation comparable, in its rapidity, to that of a saturated saline solution as seen through a microscope. But no; this is not what is actually happening. Life does not do its work so abruptly.
I detach a half-developed wing and bring it under the powerful eye of the microscope. This time I am satisfied. On the confines of the transparent network, where an extension of that network seems to be gradually weaving itself out of nothing, I can see that the meshes are really already in existence. I can plainly recognise the longitudinal nervures, which are already stiff; and I can also see—pale, and without relief—the transverse nervures. I find them all in the terminal stump, and am able to spread out a few of its folds under the microscope.
It is obvious that the wing is not a tissue in the process of making, through which the procreative energy of the vital juices is shooting its shuttle; it is a tissue already complete. To be perfect it lacks only expansion and rigidity, just as a piece of lace or linen needs only to be ironed.