The different kinds of Diatoms are innumerable; and each kind, each species, even each variety, has its own especial form, its own complex design, followed out and faithfully reproduced in hundreds of millions of individuals.
Pattern-markings, by which each variety is distinguished, formed of an infinitude of delicate lines and dots, arranged in every imaginable fashion, vary to an extent almost beyond conception. There are cases round, triangular, lengthy, many-sided, chain-like—but to picture them in words is hopeless. They have to be studied in their own wonderful minuteness and delicacy, complexity, and loveliness, before they can be known.
In all this again we surely find unmistakable evidence of a Mind, hidden, out of sight, inventing and designing.
Not the mind of the vegetable-speck, which for a brief space is sheltered in the ornate little flint-box, but of a Higher Intelligence—whether that of the Creator Himself directly, or whether, as may seem to some more probable, the mind of some intermediate Worker, Divinely appointed to the task.
Why should not Angelic or other beings, in the Unseen World, be allowed to exercise their powers in such wise, even as man upon Earth is allowed to think, to plan, to discover, to devise, to invent, according to his mental gifts?
Some such possibility may well suggest itself to a thoughtful imagination, as the variety of developments in these tiny sea-shells or cases becomes apparent. All the more, because the developments are not found scattered, haphazard, in single specimens, but—as above stated—are accurately followed out by the multitudes belonging to each variety.
It seems that every individual of every separate kind has power to form certain shapes, with certain markings, and no more. It is as if upon each minute speck of vegetable life had been originally impressed its own—not individual character, but class character. This character unconsciously expresses itself in such and such a form of shell, just as with men the individual character expresses itself in such and such outlines of face. The same may be said of Foraminifera and Radiolarian shells.
Some Diatoms have a singular power of movement; and from this sprang early mistakes, through which they were wrongly classed as animals.
Many of them grow, like ordinary plants, fixed in one spot. But many others are in continuous and regular motion. Careful study has, however, made it clear that the movements of Diatoms are purely mechanical, purely involuntary, like those of some sensitive land-plants. It is probably due to the working of food, taken into the little organism, and not obedient to any Will on its part.
It may be that herein lies the great difference between a Diatom and a Foraminifer. The one exists, but has no approach to consciousness; or, at least, probably no approach to any power of choice. The other, though of the very lowest and feeblest type of Animal-life, may yet be supposed in its infinitesimal measure to have a wish, and to be able to act upon that wish. But here we do not get beyond conjecture. Where Life exists, it may be that in all cases some dim form of consciousness exists also, which may involve some faint power of choice.