Homes Without Hands: Being a Description of the Habitations of Animals, Classed According to Their Principle of Construction

Water Spiders are now familiar to us on account of the wide-spread fashion for aquaria, but so thoroughly have the ditches and streams been ransacked by professional dealers that the creature has become quite rare in spots where it was once plentiful.

The Water Spider places her eggs in this cell, spinning a saucer-shaped cocoon, and fixing it against the inner side of the cell and near the top. In this cocoon are about a hundred eggs, of a spherical shape, and very small. The cell is a true home for the spider, which passes its earliest days under the water, and, when it is strong enough to construct a sub-aquatic home for itself, brings its prey to the cell before eating it.

The color of the Water Spider is brown, with a grayish surface caused by the thick growth of hair which covers the body, and with a very slight tinge of red on the cephalothorax. The reader must not confound this creature with another Arachnid that is sometimes called the Water Spider (Hydrachna cruenta), and is of a bright scarlet color, with a peculiar velvety surface.

THERE is an order of insects which is especially dear to anglers; not so much to fly-fishers, as to those who like to sit and look at a float for several consecutive hours. This order is scientifically termed TRICHOPTERA, or Hair-winged insects, and the various species of which it is composed are classed together under the familiar title of CADDIS FLIES.

These insects may always be known by the peculiar leathery aspect of the body, and by the coating of hair with which the wings are covered, the long hairs being spread over the whole surface, and standing boldly out like a fringe round the edge.

They all have long and slender antennæ, and in some genera, such as Mystacida, these organs are nearly three times as long as the head and body, reminding the observer of the lovely Japan moths (Adela), whose delicate antennæ wave and glitter in the sunbeams like stray threads of spider's web. For the perfect insect the angler cares comparatively little. Imitations in hair, feather, and silk are useful to the fly-fisher, and are known to anglers by the eccentric nomenclature by which such imitations are called. It is the larva in which the angler delights, and it is chiefly of the larva that our present description will treat.

We will now trace the life of the Caddis Fly from the egg to the perfect insect.

In the breeding season, the female may be observed to carry about with her a double bundle of little greenish eggs, probably in order to expose them for a certain time to the warm sunbeams before they are immersed in the water. This curious bundle is a long oval in shape, and is bent sharply in the middle, its extremities being attached to the abdomen of the insect. When her instinct tells her of the proper time, she proceeds to the water, and attaches the eggs to the leaf of some aquatic plant, often crawling down the stem for several inches. The Caddis Fly is quite at home on the water, and, unlike the dragon flies, which are quite helpless when immersed, can run on the surface with considerable speed, and on occasion can swim below the surface with scarcely less rapidity.

They may often be observed in the act of running on the water, and while they are thus employed, they often fall victims to some hungry fish, which is attracted by the circling ripples occasioned by the movement of the limbs. Fly-fishers, who are acquainted with the habits of fishes and insects, take advantage of their knowledge, and by causing their imitation Caddis Fly to ripple over the surface, or even to sink beneath it, like the veritable insect, delude the unsuspecting fish into swallowing a hook instead of a fly.

In process of time the eggs are hatched, and the young larvæ then proceed to construct houses in which they can dwell. These houses are formed of various materials and are of various shapes; and, indeed, not only does each species have its own particular form of house, but there is considerable variety even in the houses of a single species. In the accompanying illustration are shown a number of the nests formed by the Caddis Fly in its larval state, together with the perfect insects. All the figures have been drawn from actual specimens, some of which are in the British Museum, and others in my own collection. The materials of which the nest is made depend greatly on the locality in which the insect is hatched, and in a rather large series of Caddis nests now before me there are some very remarkable instances of the manner in which the insect has been obliged to adapt itself to circumstances. The most common style of case is that which is composed of a number of sticks and grass stems laid longitudinally upon each other like the fasces of the Roman consuls. Of

Caddis.

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these I have specimens of various sizes and shapes, some being barely half an inch long, while others measure four times that length, the sticks being sometimes placed so irregularly that the home of the architect is not easily seen. The creatures are not at all particular about the straightness of the sticks, but take them of any degree of curvature, as in one of the examples represented in the illustration, where the stick is not only curved, but has a large bud at the end.

Another case is made of the hollow stem of some plant, apparently that of a hemlock, to which are attached a few slips of bark from the plants. Next comes a series of cases in which the Caddis larva has contrived to secure a great number of cylindrical grass stems and arranged them transversely in several sets, making one set cross the other so as to leave a central space, in which the little architect can live. One or two cases are made wholly of bark, apparently the cuticle of the common reed, a plant which is very common in the Cherwell, whence the cases were taken. In all probability, these strips of cuticle have been dropped into the river by the water rats while feeding on the reeds.

Several cases are made entirely of leaves, mostly taken from the white thorn, which grows in great quantities along the banks of the above-mentioned river. Then there are cases which are equally composed of sticks and leaves, these materials generally occupying opposite ends of the case. There is another series of cases made up of fine grass, apparently the débris of hay which had been blown into the water during the summer, and having the materials laid across each other like the needles of a stocking-knitter. Most of these cases are balanced by a stone.

Next come a number of cases which are composed of small shells, those of the Planorbis being the most common, and having among them a few specimens of the Limnæa, or pond snail, and many separate valves and perfect shells of the fresh-water mussel. The Caddis larva is an incorrigible kidnapper, seizing on any shell that may suit its purpose, without troubling itself about the inhabitant. It is quite a common occurrence to find four or five living specimens of the Planorbis and Limnæa affixed to the case of a Caddis larva, and to see the inhabitants adhering to the plants and endeavoring to proceed in one direction while the Caddis is trying to walk in another, thus recalling the well-known episode of the Tartar and his captor. In these cases the cylindrical body is made of sand and small fragments of shells bound together with a water-proof cement, and the shells are attached by their flat sides to the exterior.

There are also several cases which are made entirely of sand cemented together, some being cylindrical, and others tapering to a point like an elephant's tusk. There are also examples of mixed structures, where the Caddis has combined shells with the leaf and twig cases, and in one of these instances the little architect has bent back the valves of a small mussel, and fastened them back to back on its house. Besides these there are one or two very eccentric forms, where the Caddis has chosen some objects which are not often seen in such a position. The seed-vessels of the elm are tolerably common, but I have several specimens where the Caddis has taken the operculum of a dead Pond-snail and fastened it to the case; and there is an example where the chrysalis of some moth, apparently belonging to the genus Porthesia, has been blown into the water from a tree overhanging the stream, and seized upon by a Caddis as a unique ornament for its house. These latter examples were found in a stream in Wiltshire, and the tusk-like sand-cases were found in a disused stone quarry in the same county.

Various experiments have been tried upon the larva of the Caddis, in order to see its mode of building. A lady, Miss Smee, has been very successful in this pursuit, and has forced the Caddis larvæ to build their nests of the most extraordinary substances, such as gold-dust, crushed glass, and other substances. They would not, however, use beads, or any thing where the surface was smooth and polished.

In this remarkable sub-aquatic home the Caddis larva lives in tolerable security, for the head and front of the body are clothed in horny mail, and the soft white abdomen is protected by the case. The food of the Caddis is generally of a vegetable nature, though there are one or two species which live partly, if not entirely, on animal food. When the larva has lived for its full period, and is about to change into the pupal condition, it closes the aperture of its case with a very strong net, having rather large meshes, and lies securely therein until it is about to change into the winged state. It then bites its way through the net with a pair of strong mandibles, comes to the surface of the water, breaks from its pupal envelope, and shortly takes to flight. The larger species crawl up the stems of aquatic plants before leaving the pupal skin, but the smaller merely stand on the cast skin, which floats raft-like on the water.

There are one or two species whose cases are not movable, but are fixed to the spot whereon they were made. In order, therefore, to compensate for the immobility of the case, the larva has a much larger range of movement. In the ordinary species, the creature holds itself to the extremity of the case by means of hooks at the end of its body, which can grasp with some force, as any one knows who has pulled a Caddis larva out of its house. But when the case is fixed, the abdominal claspers of the larva are attached to a pair of long foot-stalks, so that the creature can extend its body to some distance from the entrance of the tube.

WE now turn to the warmer seas, and shall there find some most magnificent examples of sub-aquatic homes.

Our first examples of these will be the wonderful creatures which are classed together under the general term of CORALS, and which are so familiar to us either in a manufactured state or as ornaments for the drawing-room. How vast are their submarine labors is evident from the enormous "Coral-reefs" which they raise, and which form great islands whereon an army can live, and inlets wherein a fleet can ride securely at anchor.