ing and in adhering to branches of trees, or to any other solid substance. Besides the little hooks on the pro-leg, the bottom of its foot is so arranged as to act as a sucker. The mode of walking or crawling is different in different caterpillars. Those which have pro-legs on nearly all the segments crawl on all the feet at once, moving the body straight along. Those which, on the other hand, have only a few pro-legs, manage in this way: making firm hold with their six clawed legs, they bring the prolegs, which are at the other extremity of the body, close up in rear of the true legs, thus arching the intermediate segments upward; and now, holding on with their prolegs, they thrust the anterior part of the body forward its full length. By a repetition of these movements they make a slow and measured progress. From this mode of walking such caterpillars are called loopers, or geometers, or measure-worms. Some caterpillars will stand for hours on the pro-legs in the rear part of the body, with the forward part of the body extending upward at right angles to this rear part.

480. The food of caterpillars is, with few exceptions, vegetable. Some feed exclusively on one kind of plant, as the Silkworm on the mulberry; some feed on a certain class of plants; and others on almost any kind that they happen to find. Their hours of eating differ, some eating only in the morning and evening, some all day, and others only at night. All eat a great deal—some more than twice their weight in twenty-four hours. If all animals should do this, the eatables in the world would soon be devoured. The perfect insects eat but little, for they do not grow any larger than they were when they first emerged from the pupa state. The larvæ, on the other hand, as they eat much, grow much also.

481. Caterpillars are of great service in furnishing a very large proportion of the food of birds. "It is ascer tained," says Jaeger, "that a single robin or woodpecker, and many others of the warblers, carry every day about

fifty grubs or caterpillars to their nests as food for themselves and their young. Now, if there were only one million of these birds, of which each one devours 6000 caterpillars in the months of April, May, June, and July (by no means a large computation), the number of caterpillars and grubs thus destroyed will amount to 6,000,000,000 annually."

482. Caterpillars are all spinners, the thread coming from a fleshy point in the under lip. Besides the employment of this spinning machine in making the cocoon. for the pupa state, many of them also use it as a means of escape from their enemies, letting themselves suddenly down by the thread they spin to a place of safety. If a bird espies one in a rolled-up leaf, he may not secure it, for, as he puts in his bill at one end, the caterpillar may escape at the other, dropping itself down quickly as far as it pleases.

483. Most of the caterpillars are solitary in their hab its, but some live in societies. This is the case with the Tent-caterpillars. These spin large tents of silk in the branches of trees, which are water-proof, although they are so slight in their appearance. They increase very fast, and, if let alone, colonies from the original community will spread their web-like tents in all parts of the

tree.

484. Of the caterpillars called Spanworms there are many species. The most conspicuous is what is commonly called the Canker-worm, so destructive to many fruit and shade trees from devouring their leaves. These caterpillars finish their work of devastation in June, when they are only four weeks old, and descend by their silken cords to the ground, which they enter to the depth of several inches. Here they pass into the pupa state. In the autumn they issue from the ground in the imago state. The female is wingless, and therefore must climb up the trunk of the tree to lay her eggs on the branches, which she does in clusters of a hundred or more. There

they remain till spring, when the caterpillars are hatched from them. Various expedients have been devised for destroying the females as they go up the trees to lay their eggs. The most effectual one is that adopted so extensively in New Haven to save its noble elms. It is a leaden trough placed around the trunk of the tree in which there is some kind of oil.

485. Professor Jaeger very playfully says of the habits of the perfect insects of this order that, "in comparison with the other orders of insects, they are well entitled to the rank of nobility, for among them we find no impudent beggars and spongers, as among the Flies; no parasites, as among the wingless insects; no working-class, as among the Hymenopterous insects-Bees, Wasps, and Ants; no musicians, as among the families of Crickets, Grasshoppers, Katydids, and Cicadas; but all of them are aristocratic idlers, who, clothed with silver, gold, and purple, and ornamented with ever-varying splendor, have naught to do but seek their own pleasure, and charm away their brief existence, fluttering from bough to bough, and satiating themselves with the sweet nectar of flowers."

486. We divide the Lepidoptera into two sections— the Butterflies and the Moths. The Butterflies may usually be distinguished by the vertical position of their wings when they are at rest, and by their having the antennæ slender, and club-shaped at the end. They are diurnal in their habits, and they are therefore brilliant, generally, in their colors. The under side of the wings is as beautiful as the upper. The pupa of many of this group have golden spots, from which the term chrysalis was suggested, and also aurelia, which is a Latin word of the same meaning with the former, which is Greek. These terms ought strictly to be applied only to the pupa of Butterflies, but they have come to be applied to pupa of all kinds.

487. The Butterflies are divided into five families, ac

cording to the shape of the wing. One of these families, styled by Linnæus Knights or Chevaliers, generally have a long, swallow-like tail at the extremity of the hind wings, as seen in the Troilus, Fig. 220. This Butterfly

Fig. 220.-The Troilus.

has black wings spotted with yellow. Its caterpillar is green, with a yellow stripe on each side, and a row of blue dots, while the under side of its body and its feet are reddish. In this country it is more frequently seen in the Southern than in the Northern States. The Butterfly called Berenice, Fig. 221, belongs to the family of Round-winged Butterflies. It was named after the wife of Antiochus, King of Syria, said to be the loveliest woman of her age. It is quite common with us. It has dark-red wings with black veins, and a black border with two rows of white dots. The caterpillar is of a light violet color, with brown, red, and yellow lines.

488. The second section of the Lepidoptera, the Moths,

Fig. 221.-The Berenice.

we divide into two groups, the Crepuscularia (Crepuscula, twilight), Twilight-fliers, or Hawk Moths, and the Nocturna, or True Moths. Linnæus called the Hawk Moths Sphinxes, from the peculiar attitude, resembling the sculptured Sphinx, so often assumed by the caterpillars of these Moths. Most of the species in this genus are Twilight-fliers, but not all; for some fly about in bright sunlight, sucking the nectar of flowers with their long trunks. These species are more brilliantly colored than the common species, which have a dull brownishgray aspect, like the owls, whose habits are similar. The larvæ of the Hawk Moths, on going into the pupa state, either inclose themselves in cocoons, or bury themselves in the ground. The perfect insects make a loud humming sound in their flight. The Humming-bird Moth is one of the most beautiful of the diurnal species, and is remarkable for the loudness of the humming sound which it makes while feeding poised on its wings.

489. The Nocturna, or True Moths, are by far the most extensive group of the order. They are much like most of the Sphinxes, but their antennæ are very different, being broad at the base, and tapering to a point at the end. The Cecropia, Fig. 186, is one of the most splendid of these Moths. The Silkworm Moth belongs to this group; so do all that variety of Moths, or Millers, that fly about