It is quite evident, when we have the preparatory and the ultimate stage before our eyes at the same time: the larva’s pinion is not merely a mould which elaborates the material in its own image and shapes the wing-case upon the model of its hollow. No, the membrane which we are expecting is not yet inside in the form of a bundle which, when unfurled, will astonish us with the size and the extreme complexity of its texture. Or, to be accurate, it is there, but in a potential state. Before becoming a real thing, it is a virtual thing, which is nothing as yet, but which is capable of becoming something. It is there just as much as the oak is inside its acorn. A fine, transparent rim binds the free edge both of the embryo wing and the embryo wing-case. Under a powerful lens we can see a few uncertain outlines of the future lacework. This might well be the factory in which life intends to set its materials going. There is nothing else visible, nothing to suggest the prodigious network whose every mesh will shortly have its form and place determined for it with geometrical precision. There must therefore be something better and greater than a mould to make the organizable matter shape itself into a sheet of gauze and describe the inextricable labyrinth of the nervation. There is a primary plan, an ideal pattern which assigns to each atom its precise place. Before the matter begins to move, the configuration is already virtually traced, the courses of the plastic currents are already marked out. The stones of our buildings are arranged in accordance with the architect’s considered plan; they form an ideal assemblage before existing as a real assemblage. Similarly, a Locust’s wing, that sumptuous piece of lace emerging from a miserable sheath, speaks to us of another Architect, the Author of the plans which life must follow in its labours. The genesis of living creatures offers to our contemplation, in an infinity of ways, marvels far greater than those of the Acridian; but generally they pass unperceived, overshadowed as they are by the veil of time. The lapse of years, with its slow mysteries, robs us of the most astonishing spectacles, unless our minds be endowed with a stubborn patience. Here, by exception, things take place with a swiftness that arrests even a wavering attention. He who would, without wearisome delays, catch a glimpse of the inconceivable dexterity with which life does its work has but to go to the great Locust of the vines. The insect will show him that which, with their extreme slowness, the sprouting seed, the budding leaf and the blossoming flower hide from our curiosity. We cannot see a blade of grass grow; but we can easily witness the growth of a Locust’s wings and wing-cases.