FAM. 54. MALACODERMIDAE.—_Seven (or even eight) visible ventral segments, the basal one not co-adapted in form with the coxae; tarsi five-jointed. Integument softer than usual, the parts of the body not accurately co-adapted._ This important family includes a variety of forms: viz. Lycides, Drilides, Lampyrides, Telephorides; though they are very different in appearance, classifiers have not yet agreed on separating them as families. Of these the Lampyrides, or glow-worms, are of special interest, as most of their members give off a phosphorescent light when alive; in many of them the female is apterous and like a larva, and then the light it gives is usually conspicuous, frequently much more so than that of its mate; in other cases the males are the most brilliant. The exact importance of these characters in the creatures' lives is not yet clear, but it appears probable that in the first class of cases the light of the female serves as an attraction to the male, while in the second class the very brilliant lights of the male serve as an amusement, or as an incitement to rivalry amongst the individuals of this sex. {249}[Illustration: Fig. 129—_Phengodes hieronymi._ Cordoba, South America. (After Haase.) A, Male; B, female. _l_, _l_, Positions of luminous spots; _ls_, spiracles. About × 3.] The well-known fire-flies (_Luciola_) of Southern Europe are an example of the latter condition. They are gregarious, and on calm, warm nights crowds of them may be seen moving and sparkling in a charming manner. These individuals are all, or nearly all, males; so rare indeed is the female that few entomologists have even noticed it. The writer once assisted in a large gathering of _Luciola italica_ in the Val Anzasca, which consisted of many hundreds of specimens; all of those he caught, either on the wing or displaying their lights on the bushes, were males, but he found a solitary female on the ground. This sex possesses ordinary, small eyes instead of the large, convex organs of the male, and its antennae and legs are much more feeble, so that though provided with elytra and wings it is altogether a more imperfect creature. Emery has given an account of his observations and experiments on this Insect, but they do not give any clear idea as to the exact function of the light.[125] In our British glow-worm the female is entirely apterous—hence the name glow-worm—but the male has elytra and ample wings, and frequently flies at night into lighted apartments. Although so little has been ascertained as to the light of Lampyridae, there are two facts that justify us in supposing that it is in some way of importance to the species. These are: (1) that in a great many species the eyes have a magnificent and unusual development; (2) that the habits of the creatures are in nearly all cases nocturnal. It is true that the little _Phosphaenus hemipterus_ is said to be diurnal in habits, but it is