Popular Science Monthly/Volume 5/October 1874/Microscopic Architects
THERE is a world of hidden beauty of which we can form no conception without the aid of the microscope. This instrument reveals a real fairy-land, of which we may sometimes have dreamed; but our wildest fancy is more than realized by the glimpses it affords of wonderfully beautiful plants and animals. Here is a world teeming with life and animation, whose inhabitants seem to possess skill and intelligence, and have worked on, unnoticed, for ages and ages.
Some of these tiny animals are architects of no mean order, building their abodes of separate bricks or pellets, laying them in tiers, as a mason or bricklayer would build a house. One of the most beautiful of these animals is the Brickmaker [Melicerta ringens). Fig. 1 represents it as seen with a magnifying power of 160 diameters. It was known to Leuwenhoek nearly two hundred years ago, or about the beginning of the eighteenth century. A few years later Linnæus mentions the marvelous beauty of this tiny workman, and comments upon the regularity and beauty of the house in which it dwells. If these early observers found so much to admire, with the imperfect instruments of that day, how much more are we enabled to see clearly
the wonderful visions presented to us by the greatly improved microscopes of to-day!
Although Melicerta ringens was known so long ago, yet Mr. Gosse was the first to describe the manner of its building its abode. The few who have made these microscopic creatures a study have recorded their labors in many volumes, scarcely attainable to the ordinary lover of natural history.
The animals figured and described here are as seen through a binocular microscope, with a magnifying power of 160 diameters. This power enables us to clearly define each separate brick in the tube of Melicerta, and to note the firmness and regularity of the structure. Although built of round bricks, yet it is so constructed that there are no interstices or spaces between. No bird, no other animal, not even man himself, can excel the beautiful workmanship of this tiny creature, scarcely visible to the naked eye, yet, under the microscope, assuming vast proportions. She not only builds her house, but manufactures her own brick, and lays them up one by one with no workmen to assist. The house is usually attached to some water-plant; but I have seen the young ones, upon a few occasions, anchor their dwellings to the parent-house.
When the animal is resting, or is in any way disturbed, she settles down in the lower part of the tube; but, when all is quiet and she is in good working condition, with no nursery of young ones around her, she is pretty sure to reward us with the sight of her four beautiful wheels, which she sets in rapid motion, thus forming a swift current which brings the food and the material for the brick close to her head; and she has the power of selection, for she often rejects particles brought to her mouth. The apparatus for moulding the brick is within the body. The material is brought through the action of the wheels to a small opening, where it is passed down to the apparatus, which is in rapid, whirling motion, soldering the particles together until they become, seemingly, a solid ball; now she ejects the brick from its mould, bends her head over, and. securely places it on top of the structure. It takes her about three minutes to manufacture each brick.Finding one with a tube so long that only a part of the flower-like head could appear above the battlement, I cut about one-third of the tube away, replaced it under the microscope, and watched for the reappearance of the creature. She soon came forth, and, rather hastily, rushed up beyond the decapitated story of her house until she reached her accustomed height, when she began to unfold her petal-like lobes. Now, evidently for the first time aware of something amiss, she shot back into her house much quicker than she came up. This she repeated several times before seeming to have courage to investigate; at last she set her wheels in motion, and threw herself from side to side—quite nervous-like—not seeming to relish the situation, or really
to quite comprehend what the matter was with her surroundings. It was some hours before she resumed her occupation of brickmaking, and, when one was completed, it was very amusing to watch her efforts to place it; she wasted a quantity of brick before she became aware how low down she must reach in order to rebuild, but this at last she learned, and now the work was rapidly carried forward; she had placed several new tiers around her dwelling when an accident prevented my further observation. There was no difficulty in seeing where the building recommenced, for the new brick was very much lighter colored than the old.
Fig. 2 represents the beautiful Floscule. Microscopists call it Floscularia ornata. Like the Brickmaker, it lives in a house, a transparent, glass-like house, which I frequently find broken, sometimes entirely demolished, as if the tenant had been in some skirmish, but they seem to get along very well without a house.
The Floscule here represented was probably blessed with an amiable disposition, and had lived a peaceable life, for she was large and well developed, and had an unbroken house to dwell in, through which we could see two large eggs near the bottom. When the eggs hatch, the little animals leave their mother's house and go floating off, living a free-and-easy sort of life; but, after a few days of this wandering, gypsy kind of existence, they seem to become impressed with the graver duties of life, and settle down and set up house-keeping on their own account.
Like the Brickmaker, the Floscule has a long footstalk, which she fastens to the leaf of some water-plant, where she remains moored during the rest of her life. She seems to be a very nervous, sensitive creature; for the slightest jar upon the table, or sometimes even a step upon the floor, or the closing of a door, will quickly send her into her glass-like house, where she settles down in a heap, looking scarcely more than an animated mass of jelly. But, if all is quiet, she soon begins to unfold, stretches out her long footstalk, which pushes up her bell-shaped body, surmounted by a mass of fine bristly filaments, which look like a dense cloud of smoke issuing from the opening at the top; and, as she gradually unfolds, we see there are five lobes to which the hair-like filaments are attached, which now begin to spread out like a fan (see Fig. 2). As nothing is made in vain, these filaments must in some way be of use to the animal. She cannot go in search of food, for she is firmly anchored to one spot, and has no wheels to set in motion to form a current to bring food to her: so we will carefully watch and see how she captures her prey. Here comes a little floating monad. Ah, it is caught among the bristly filaments, and flies wildly about as if bewildered; but, instead of retreating and getting away, it goes down, down, until it reaches the wide opening. This opening is surmounted by the five lobes which bear the filaments, but it is not the Floscule's mouth, the mouth is situated lower down (see Fig. 2), and works something like a steel-trap. Well, the little monad has got into this opening and seems to have recovered from its fright, as there is plenty of room for it to float about here; but the Floscule is now on the alert, the monad is doomed! If it tries to escape, those lobes that stand up so
innocent-like, with their beautiful fan-shaped filaments, immediately curve over and close the opening. This movement of the Floscule usually sends the little monad close to that terrible steel-trap, when it is snapped up in a moment. Our ears are so heavy and dull, or we might fairly hear the click of her teeth, so large and voracious does she appear.
Sometimes an animal is betrayed into the opening too large for the Floscule to manage, and it is very amusing to watch its efforts to escape, and to see the Floscule try to devour it; she makes many attempts to take it into her mouth, but, at last, seeming to become discouraged, she opens wide the door and gives it permission to leave.
Fig. 3 introduces us to one of the most lovely of microscopic objects, the Tree Vorticella (Carchesium polypinum). Although this animal cannot be said to build a house, yet, in one sense, it is an architect, for a tree is built up in some way, and the little bell-shaped creatures hang on the ends of the branches, where they look more like flowers than animals. The stem of the tree is transparent and seems to be jointed, and the little creatures can swing the branches about, and even throw them into a spiral coil, so as to bring them close to the trunk of the tree. This gives them the appearance of being wonderfully polite: they bow and courtesy to each other as if preparing for a grand quadrille; and they are decked out in gay colors, red and green, and yellow, and the margin of the little cup is beautifully fringed with cilia, which are in rapid motion, producing a current which brings their food to them.
But one of the most curious sights I ever beheld was a Cyclops, with a Tree Vorticella growing on its back. It was a larger tree than here represented, and a different species; the branches were more straight, and much more numerous. Only think of it, an animal swimming about with a great tree of living freight on its back! But
they did not seem to have much control over the Cyclops, for he dashed about as if he did not care how many he knocked overboard! But, alas! the poor Cyclops, with his strange freight, came to grief. I undertook to transfer him to the live-box, so that our artist might have him more under control, when I brought down the cover a little too close, crushing him in the operation. This sent the vorticellas flying off their stems, and all was spoiled.
Fig. 4 represents a front view of Paramecium caudatum. He is not an architect, but a wandering, idle sort of fellow, often seen in company with our more staid and settled house-keepers. He gets into the oddest shapes imaginable. If he is a little cramped for room it does not seem to inconvenience him in the least, for his body is so flexible he can make it fat and dumpy, or long and slender, just as the occasion seems to require. If they have any police regulations in this fairy-world, he must be a great trial to the authorities, eluding their grasp, and bowing to them from some other quarter, entirely transformed. But, when there is nothing to interfere with his locomotion, he looks very much like a leaf, as is seen in our figure. He is covered all over with rather short, stiff hairs, or cilia, that look like porcupine-quills—perhaps they are his weapons of defense. He is not carnivorous, but lives on a vegetable diet, and is so transparent that we can always tell what he has taken for his dinner. His favorite food seems to be diatoms. These are beautiful little plants encased in a shell of various forms and colors. This curious animal sometimes manages to swallow two diatoms at once, almost as long as his body, and then he seems rather awkward and stiff, with two great logs on his stomach! But he manages, somehow, to absorb the nutritious, vegetable part of the diatom, and throws aside the beautiful transparent shell, which he has not broken nor injured at all in the operation.