APPENDIX.

NATURAL HISTORY OF WORMS.

THE EARTH WORM.

THE class of animated creation which comes next to be described, is animals of the worm kind, which being, like serpents, entirely destitute of feet, trail themselves along upon the ground, and find themselves a retreat under the earth, in the water, or shut up in the bodies of other living beings. But though they have the same creeping motion as serpents, there are other marks which sufficiently distinguish them from each other. The serpent, as has been said, having a back bone, which it is incapable of contracting, bends its body into the form of a bow, and then shoots forward from the tail; but it is very different with the worm, which has a power of shortening or lengthening itself at will. There is a screw shaped muscle, that runs round its

whole body. from the head to the tail, somewhat resembling a wire wound round a walking-cane, which, when slipped off, and one end extended and held fast, will bring the other nearer to it; in this manner it moves onward, not without great effort; but the occasions for progressive motion are few.

As the earth worm is designed for living under the earth, and leading a life of obscurity, so it seems admirably adapted to its situation. Its body is armed with small stiff sharp burrs, or prickles, which it can erect or lower at pleasure; under the skin there lies a slimy juice, to be ejected as occasion requires, at certain pores, between the rings of the muscles, to facilitate its passage into the earth; it has breathing-holes along the back, adjoining each ring; but it is without bones, without eyes, and properly speaking, without feet. It has a mouth, and also an intestine, which runs along to the very point of the tail. This is always filled with a very fine earth, which seems to be the only nourishment these animals are capable of receiving.

The animal is entirely without brain; but near the head is placed the heart, which is seen to beat with a very distinct motion.

When the eggs are laid in the earth, which, in about fourteen days, are hatched into maturity, the young ones come forth very small, but perfectly formed, and suffer no change during their existence: how long their life continues is

not well known, but it certainly holds for more than two or three seasons. During the winter, they bury themselves deeper in the earth, to secure themselves from being frozen, and in spring, on moist or dewy evenings, they revive with the rest of nature, and come forth from their retreats, for the universal purpose of continuing their kind. They chiefly live in a light, rich and fertile soil, moistened by dews or accidental showers, but avoid those places where the water is apt to lie on the surface of the earth, or where the clay is too stiff for their easy progression under ground.

Helpless as they seem to be formed, yet they are very vigilant in avoiding those animals that chiefly make them their prey; in particular the mole, who feeds entirely upon them beneath the surface, and who seldom ventures, from the dimness of its sight, into the open air; him they avoid, by darting up from the earth, the in stant they feel the ground move; and fishermen, who are well acquainted with this, take them in what numbers they chuse, by stirring the carth where they expect to find them. They are also driven from their retreats under ground, by pouring on them bitter or sour water, such as that water in which green walnuts have been steeped.

To the incurious, earth worms seem to belong to a most insignificant tribe; and yet they have weighty influence in the economy of nature;

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for to say nothing of half the birds and some quadrupeds that are supported by them, worms seem to be the great promoters of vegetation.This they do by boring, perforating, and loosening the soil, and rendering it open to receive rain and the fibres of plants, by drawing straws and stalks of leaves and twigs into it; and most of all, by throwing up such infinite numbers of lumps, called worm-casts, which form a tine manure for grass and corn!

Gardeners and farmers express their detestation of worms; the former, because they render their walks unsightly, and make them much work; and the latter, because they think worms eat their green corn. But these men would find

that the earth without worms would soon become cold, hard-bound, and void of fermentation; and consequently sterile. And besides, in favour of worms, it should be observed, that green corn, plants, and flowers, are not so much injured by them, as by many species of insects in their larva state and by unnoticed myriads of those small shell-less snails, called slugs, which silently and imperceptibly, make amazing havock in the field and garden.

Lands that are subject to frequent inundations are always poor: one great reason of this may probably be, because all the worms are drowned.

Dew worms make their casts principally in the months of March or April, in mild weather.

In rainy nights they travel about, as appears from their sinuous tracks on a soft, muddy soil, perhaps in search of food. When they appear at night on the turf, although they considerably extend their bodies, they do not quite leave their holes, but keep their tails firmly fixed, so that, on the least alarm, they can precipitately retire under the earth. Whatever food falls within their reach, when thus extended, they seem content with it, such as blades of grass, or fallen leaves.

THE ASCARIS.

THE former species of worm found its retreat, under ground, the one we are about to describe is produced and lives in the intestines of very thin persons; there they are most abundant, but sometimes they ascend into the stomach, and even creep out at the mouth and nostrils. When very numerous, they give rise to unpleasant, and sometimes even to fatal disosders.

They are supposed to fix themselves by three little knobs on the extremity of their body, whilst they suck the nutritive juices, on which they are supported, through a small triangular aperture, which is situated in the center, betwixt these knobs. Their interior organization apppears