This Insect (_Campodea staphylinus_) is, so far as external form goes, well known, from its having been figured in many works on natural history on account of its having been supposed to be {183}the nearest living representative of a primitive or ancestral Insect. The creature itself is but little known even to entomologists, although it is one of the commonest of Insects over a large part of Europe. It is numerous in the gardens and fields about London and Cambridge, and abounds in damp decaying wood in the New Forest; if there be only one species, it must possess an extraordinary capacity for adapting itself to extremes of climate, as we have found it at midsummer near the shores of the Mediterranean in company with the subtropical white ants, and within a day or two of the same time noticed it to be abundant on the actual summit of Mount Canigou, one of the higher Pyrenees, where the conditions were almost arctic, and it was nearly the only Insect to be found. The species is said to exist also in North America and in East India. It is a fragile, soft Insect of white colour, bending itself freely to either side like a Myriapod; the legs are rather long, the antennae are long and delicate, and the two processes, or cerci, at the other extremity of the body are remarkably similar to antennae. It has no eyes and shuns the light, disappearing very quickly in the earth after it has been exposed. If placed in a glass tube it usually dies speedily, and is so extremely delicate that it is difficult to pick it up even with a camel's hair brush without breaking it; so that we may fear it to be almost hopeless to get enough specimens from different parts of the world to learn what differences may exist amongst the individuals of this so-called primitive Insect. Meinert, a very able entomologist, considers that there is really more than one species of _Campodea_. [Illustration: FIG. 91.—_Campodea staphylinus._ (After Lubbock, × 15.)] Campodeidae as a family may be briefly defined as Thysanura with the trophi buried in the head and with the body terminated by antenna-like processes. We shall consider some of the anatomical peculiarities of this interesting Insect after we have {184}briefly reviewed some of the external characters of the other Thysanura.