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are so many of them that the bird seems to have found some special gratification in making them, just as a boy who has a new knife makes havoc on every piece of wood which he can obtain. When the holes are completed, the bird next procures its thread, which is a long fibre of some plant, generally much longer than is needed for the task which it performs. Having found its thread, the feathered tailor begins to pass it through the holes, drawing the sides of the leaf towards each other so as to form a kind of hollow cone, the point downwards. Generally a single leaf is used for the purpose, but whenever the birds cannot find one which is sufficiently large, it sews two together, or even fetches another leaf and fastens it with the fibre. Within the hollow thus formed the bird next deposits a quantity of soft white down, like short cotton wool, and thus constructs a warm, light, and elegant nest, which is scarcely visible among the leafage of the tree, and which is safe from almost every foe, except man.'
Amongst insects there are many beautiful instances of pensile nest makers, both in the larval and perfect condition; and here again we notice the Hymenoptera as deserving the chief attention, on account of the variety, beauty, and singularity of the homes they construct. We have already noticed the wasp as a burrower; there are wasps which are also builders of pendent nests, these are popularly called tree-wasps, such as the Vespa Norwegica, the Vespa sylvestris, and the Vespa borealis or arborea. The nests, which are pretty little objects, and familiar to almost every one, are often swung from the extremity of a branch; one species prefers silver firs, another gooseberry trees. In the animal-architecture room of the British Museum may be seen several specimens of nests made by the pasteboard wasps (Chartergus nidulans), which attract notice at once by their large size and singular shape.' Réaumur was, we believe, the first to give a description of these interesting specimens of insect architecture. This wasp, as his name implies, is a pasteboard manufacturer; the nest is supported from the branch of a tree; the card with which he forms the exterior covering of his abode is so smooth, so strong, so uniform in its texture, and so white, that the most skilful manufacturer of this substance might be proud of the work. It takes ink admirably. The nest is impervious to water. It hangs upon the branch of a tree, and those rain drops which penetrate through the leaves never rest upon its hard and polished surface. A small opening for the entrance of the insects terminates its funnel-shaped bottom. It is impossible to unite more perfectly the qualities of lightness and strength.' The inside of the nest consists of several circular platforms, fixed all round to the sides; they are smooth above, and have their hexagonal cells on the under surface; the centre of each platform is perforated
for the admission of the wasps at the extremity of a short funnelshaped projection, and through this access is gained from story to story. These nests, unlike that of the common wasp of this country, are occupied for successive seasons by their builders. A specimen of the pasteboard-wasp's nest from Ceylon has been found which was of the astonishing length of six feet. The nests of Polistes, another genus of hymenopterous insects, are extremely curious. We must refer the reader to the British Museum, where will be found several of these nests, as also those of various other genera, such as Icaria, Raphigaster, Mischocyttarus, Apoica, Polybia, &c.
Let us leave further notice of the denizens of the field or air, and take a glance at what is going on in the sub-aquatic world.
Fishes as architects first claim our attention. It is well known that certain kinds of fish make nests, in which the eggs are developed, and the little fry take shelter. Even in the time of Aristotle, the nest-making peculiarities of some kinds of fish attracted attention. The father of natural history thus writes:
Of river fish the male glanis manifests great care for its young; the female, after having deposited her eggs, goes away, but the male continues to guard them, paying only so much of attention to them as to drive away other fish lest they should carry the eggs away. He does this for the space of forty or fifty days, till the fry have grown strong enough to escape being devoured by other fish.' Aristotle also speaks of a fish called the Phycis as being the only marine species which manifests the same anxious care for its brood. The phycis is probably a species of goby found in the Adriatic. The male makes his nest of the roots of grass rack (Zostera marina), that long ribbon-shaped weed, with its beautiful grass-green leaves, common on our own shores. It is probable, too, that this is the fish to which Ovid alludes in the Halieuticon,' 122.
Atque avium dulces nidos imitata sub undis.' The best instances of architecture among the fishes are those which are produced by the sticklebacks (Gasterosteus), those wellknown little beings whose spiny bodies, brilliant colours, and dashing courage make them such favourites with all who study nature :
"These fishes make their nests of the delicate vegetation that is found in fresh water, and will carry materials from some little distance in order to complete the home. They do not, however, range to any great extent, because they would intrude upon the preserve of some other fish, and be ruthlessly driven away. When Vol. 120.-No. 240.
the male stickleback has fixed upon a spot for his nest, he seems to consider a certain area around as his own especial property, and will not suffer any other fish to intrude within its limits. His boldness is astonishing, for he will dash at a fish ten times his size, and by dint of his fierce onset and his bristling spears, drive the enemy away. Even if a stick be placed within the sacred circle, he will dart at it, repeating the assault as often as the stick may trespass upon his domains. Within this limit, therefore, he must seek materials for his nest, as he can hardly move for six inches beyond it without intruding upon the ground of another fish. Although the nests of the stickleback are plentiful enough, they are not so familiar to the public as might be expected, principally because they are very inconspicuous, and few of the uninitiated would know what they were, even if they were pointed out. Being of such very delicate materials, and but loosely hung together, they will not retain their form when they are removed from the water, but fall together in an undistinguishable mass like a coil of tangled thread that has been soaked in water for a few weeks. The materials of which the nest is made are extremely variable, but they are always constructed so as to harmonize with the surrounding objects, and thus to escape ordinary observation. Sometimes it is made of bits of grass which have been blown into the river, sometimes of straw, and
sometimes of growing plants. The object of the nest is to protect the eggs from the numerous enemies that would devour them, the worst enemies of all being probably the sticklebacks themselves.'*
The habits of spiders are always well worth close observation, and the architectural skill which some species display in the construction of their homes or snares is extremely interesting. The great water-spider (Argyronetra aquatica) yields to none of its kind in its architectural powers. Spinning a web of silk which it attaches to some submerged plant, this spider fills it with air needful for respiration. Within this house, that looks like a ball of silver, the water-spider deposits her eggs and hatches her little ones. Spiders breathe atmospheric air, and could not long survive if immersed in water without the requisite oxygen. The precise analogy, as Mr. Wood remarks, between the nest and the diving-bell of the present day is too obvious to need a detailed account.' There had long been a question as to the mode in which the air was introduced, some maintaining that the air was evolved by the plant upon which the nest was fixed. To the experiments of Mr. Bell naturalists are indebted for the solution of this interesting problem, and subsequent observers have abundantly verified the above-named gentleman's account. Placing specimens of argyronetre in different glass vessels with water-weed, he carefully watched their habits. He saw the spider constructing its silky habitation, and ascending to the surface at intervals, taking down with it each time a bubble of air which it left in connection with the nest.
* We remember noticing in a bottle of whitebait, purchased by a friend in London, four or five specimens of the three-spined sticklebacks! Our worthy friend, when dining at a well known hotel in Covent Garden, was surprised to find a few spines sticking in his tongue and between his teeth.
'In this way no less than fourteen journeys were performed, sometimes two or three very quickly one after the other; at other times with a considerable interval between them, during which time the little animal was employed in extending and giving shape to the beautiful transparent bell, getting into it, pushing it out at one place, and amending it at another, and strengthening its attachments to the supports. Āt length it seemed to be satisfied with its dimensions, when it crept into it and settled itself to rest with the head downwards. The cell was now the size and nearly the form of half an acorn cut transversely, the smaller and rounder part being uppermost. The manner in which the animal possesses itself of the bubble of air is very curious. It ascends to the surface slowly, assisted by a thread attached to the leaf or other support below and to the surface of the water. As soon as it comes near the surface it turns with the extremity of the abdomen upwards, and exposes a portion of the body to the air for an instant, and then with a jerk it snatches, as it were, a bubble of air, which is not only attached to the hairs which cover the abdomen, but is held on by the two hinder legs, which are crossed at an acute angle near their extremity, the crossing of the legs taking place at the instant the bubble is seized. The little creature then descends more rapidly, and regains its cell, always by the same route, turns the abdomen with it, and disengages the bubble.'
Every one who has ever looked into a pond or river is acquainted with certain forms of animal life which construct for themselves tenements of small sticks, rushes, aquatic weeds, shells, gravel, and other substances. At first sight a person would suppose that these bundles of twigs were gifted with locomotion, for the head and legs of the lodger, which are the only portions which are protruded, are not always visible; these walking-sticks' are made by the larva of certain species of insects, which from their habits have received the name of Phryganide* from some naturalists. The larva is a soft-bodied maggot, with the exception of its head, which is hard ; it has strong jaws, and two curved hooks at the end of the last segment, by means of which the creature fastens itself to its house. In still-water the houses are chiefly built of light materials, such as twigs and bits of grass, but where the current is strong more solid and heavier substances
* From the Greek opúsavov, “ a dry stick.' The sticks being immersed in water, however, are always wet. 2 D2
are used to prevent the stream sweeping them away. Caddisworm tenements are not unfrequently made of shells of molluscs, especially of the circular planorbis, the animals being often alive and carried about wherever the captor wishes. Some curious experiments have been made by a lady with these caddis-worms; having turned a number of animals out of their houses, she placed in the vessel with them various materials, such as pieces of coloured glass broken small, cornelian, agates, onyx stones, bits of broken marble, slender sprigs of coral, brass-shavings, gold and silver leaf, coralline, and pieces of tortoiseshell, and then watched the manner in which they dealt with these materials. It was found that coralline forms a very curious dwelling; Miss Smee, the authoress of the experiments, says that the pieces of the skeleton blanched coralline are put together in such a manner that the case has an appearance as if it had been the work of a basketmaker instead of that of a larva.
'But perhaps a more singular-looking case than even these wickerwork ones are those which are made from pieces of tortoiseshell, such as fragments of the teeth of a tortoiseshell comb. If these be given to a worm, it will be seen that it will arrange them crosswise. In doing so it will make its house slightly resemble a hedgehog whose bristles are erected. It seems astonishing that there is such a variety of forms in the appearance of these different caddis cases. For what can be more unlike each other than cases made from fragments of the teeth of a comb and that from the pieces of skeleton coralline? What is more extraordinary is that the same worm which can build the basket-looking case can also construct the one resembling a hedgehog when its bristles are erected. In fact, if a caddis is able to make itself a case from any one of the substances already mentioned, it is able to build from all of them. For I have tried their capabilities in that way by giving a caddis a certain kind of material to construct his house, and as soon as it was completed I turned it out, and then gave the same worm something different to work upon.'
The following interesting account of the manner in which caddis-worms construct their houses is by the same lady :
• The worms commence by placing together a number of the pieces of the substances they wish to employ. These are then cemented loosely together so as to make a foundation for building its subsequent structure. These first pieces that are used as a foundation are always cast off before the completion of the edifice. The cement used by the caddis in fastening the pieces of its house together is a secretion which proceeds from its mouth. With it the different pieces are fixed together in the most perfect manner. This cement answers the same purpose to the caddis-worm as the mortar which is used by the bricklayer in the construction of his buildings. After the foundation has been formed, the caddis proceeds by lifting up with its feet a piece of