moss, or stones, the eaves of out-houses, and similar places, are industriously sought after, and many bury themselves a considerable depth in the earth. But the selection of a suitable retreat is far from being their only care, at least with a great many; other precautions are resorted to, many of which afford examples of singular ingenuity and persevering labour. This is particularly the case with the caterpillars of butterflies and moths. The former either suspend their chrysalides horizontally by the tail and a silken band round the middle, or by the tail alone, allowing the body to hang perpendicularly. The manœuvres by which the caterpillar manages to place the band round its body are extremely curious and interesting, and have, therefore, been particularly described in the volume of this series already mentioned and to which we must again refer. The cocoons of moths have likewise been described in a similar volume devoted to their history; and that tribe of insects affords the best examples of this species of fabrication. Most of the Hymenoptera likewise form silken cocoons; a few Coleopterous and Dipterous genera, (Hypera, Donacia, Mycetophila,) and the Neuropterous groups Hemerobius and Myrmeleon; the latter differing from nearly all the rest in having the apparatus for spinning their threads at the extremity of the abdomen, instead of in the head. Cocoons of silk are often strengthened by the addition of other materials, such as particles of earth, portions of leaves, fragments of wood, &c.; and occasionally cocoons are formed altogether of these substances held together by
