21 2 



ORTHOPTERA 



CHAP. 



an earlier one which he failed to notice, and his observa- 

 tion 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-bear- 

 ing 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 

 Fig. 112. Notal plates from which differ greatly in the earlier and later 



the tegmina and wings of Forji- 

 cula auricularia are developed in 

 young, A, and more advanced, B, 

 nymph. 



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 appear- 

 ance indicating that the wings themselves are present and packed 

 about a centre, as shown in W of B, Fig. 112, 



In the young of the common earwig the number of joints ^ in 

 the antennae increases with age. Camerano, I.e., says that before 

 emergence from the Qgg there are apparently only 8 joints in the 

 antennae, and Fischer states that the larvae of F. auricularia 

 have at first only 8 antennal joints ; later on 1 2 joints are 

 commonly found, and, according to Bateson,^ this number 

 occasionally persists even in the adult individual. Meinert says ^ 

 that the newly hatched Forficula has either 6 or 8 joints, and 

 he adds that in the later portion of the preparatory stage the 

 number is 12. Considerable discrepancy prevails in books as to 

 the normal number of joints in the antennae of the adult F. 

 auricularia, the statements varying from 13 to 15. The latter 

 number may be set aside as erroneous, although it is, curiously 



^ It may be worth while to repeat that "joint" means a piece, and is the 

 equivalent of "link" in a chain. 



2 Ifaterials for the Study of Variation, 1894, p. 413. 



3 Naturhist. Tidsskrift, 3rd ser. ii. 1863, p. 474. 



