The ovaries of _Labidura riparia_ and _Forficula auricularia_ are extremely different. In _L. riparia_ there are on each side five tubes, each terminating separately in an obliquely directed lateral part of the oviduct. In _F. auricularia_ there is but one tube on each side, but it is covered by three longitudinal series of very short sub-sessile, grape-like bodies, each of the two tubes being much dilated behind the point where these bodies cease. The testes in earwigs are peculiar and simple; they consist, on each side, of a pair of curvate tubular bodies, connected at their bases and prolonged outwards in the form of an elongate, slender vas deferens. The structures in the males of several species have been described at some length by Meinert,[137] who finds that in some species a double ejaculatory duct exists. [Illustration: FIG. 111.—Ovaries of _Labidura riparia_, A; and _Forficula auricularia_, B. (After Dufour.)] The young is similar to the adult in form; in the winged forms it is always easy to distinguish the adult by the full development of the wings, but in the wingless forms it can only be decided with certainty that a specimen is not adult by the softer and weaker condition of the integuments. Scarcely anything appears to be known as to the life-history, except a few observations that have been made on the common earwig; Camerano found[138] that this Insect has certainly three ecdyses, and possibly {212}an earlier one which he failed to notice, and his observation confirms the vague previous statement of Fischer. The eggs, in the neighbourhood of Turin, are deposited and hatched in the early spring; in one case they were laid on the 10th March, and the Insects issuing from them had completed their growth and were transformed into perfect Insects on the 22nd May. In the immature state the alar structures of the future imago may be detected. The tegmina-bearing sclerites, _t_, Fig. 112, look then somewhat like those of some of the apterous forms (Fig. 106) and, as shown in A and B, Fig. 112, do not differ greatly in the earlier and later stages. The wings, however, change much more than the tegmina do; at first (Fig. 112, A) there is but little difference between the two, though in the interior of the wing-flap some traces of a radiate arrangement can be seen, as shown at _W_ in A, Fig. 112; in a subsequent condition the wing-pads are increased in size and are more divided, the appearance indicating that the wings themselves are present and packed about a centre, as shown in _W_ of B, Fig. 112. [Illustration: FIG. 112.—Notal plates from which the tegmina and wings of _Forficula auricularia_ are developed in young, A, and more advanced, B, nymph.]