you would see a packet of threads huddled together between the four hindmost of the scaly legs. The greater the height ascended the greater is the size of this packet. All the turns of the thread which compose it are entangled. So the caterpillar does not consider it of any value. As soon as the insect can walk it gets rid of the mass, sets its legs free, and leaves it behind before one or at most two steps have been taken. The cord is wasted on each ascent, but the caterpillar can afford to lose as many as it likes, for it has in itself the source of the matter necessary for the composition of the thread, and it is a source from which that which was drawn off is being continually re-supplied. Moreover, spinning the thread costs the caterpillars but little; indeed, the loopers economise this thread so badly that most of them leave it behind them wherever they go." They are found on many trees, but particularly on the oak, the foliage of which they often entirely devour. They burrow into the ground to change into chrysalides, and undergo all their metamorphoses in the course of the year. Others do not become perfect insects till the autumn, or sometimes not even till the following spring. A few assume the perfect state in winter. There are, indeed, some of these, such as the males of the _Hybernias_, which fly about on the foggy evenings of November. The females of this genus have either no wings at all, or else only rudimentary ones. Two species, the _Hybernia defoliaria_, or Winter Moth, and the _Chimatobia brumata_, abundant here, are very common in the environs of Paris. [Illustration: Fig. 262.--Hybernia leucophearia, male.] M. Maurice Girard says, in his work on the metamorphoses of insects, that the females of these moths can easily be found at the beginning of November, in a very strange place, namely, on the gas lamps of the public promenades; for instance, along the roads in the Bois de Boulogne. No doubt they had climbed up to this height, attracted by the light, or perhaps had been carried thither by the males, which fly, having wings. [Illustration: Fig. 263.--Winter Moth (_Hybernia defoliaria_), male.] [Illustration: Fig. 264.--Winter Moth (_Hybernia defoliaria_), female.] In February and March appear other analogous species. "We may find," says M. Maurice Girard, "near Paris, in the meadows which surround the confluence of the Seine and the Marne, at the end of the month of March, the _Nyssia zonaria_ (Fig. 267), the males of which insect remain during the day motionless on the grass."[72] [72] With us this insect has a very limited range, being only found at New Brighton, near Birkenhead, where it is most abundant.--ED. [Illustration: Fig. 265.--Chimatobia brumata, male.] [Illustration: Fig. 266.--Chimatobia brumata, female.]