Phasmidæ certainly surpass all others in length. Many of them measure half-a-foot from one extremity to the other, and one of them, (P. gigas) occasionally attains the length of about nine inches. The resemblance of the narrow bodied kinds to a small branch, is in many instances remarkably close, and this in connection with other peculiarities, is no doubt often the means of preserving them from the attacks of other animals. Were this not the case, they would fall an easy prey to their enemies, for they are ill fitted to act on the defensive, and the slowness of their movements affords but little chance of escape by flight. Among the other peculiarities alluded to, may be mentioned the spines with which many of them are beset, particularly on the head and thorax. As an example of this sort, P. cornutum, a large species, may be cited, whose frontal horns give such a formidable expression to its head, that it would not be supposed a priori to belong to a creature of perfectly innoxious habits.
To enable them to cling to branches, and "drag their slow length along," the tarsi in general are much developed; the basal joint especially is often long