Ixviii INTRODUCTION. 



Details of such may be seen, Plate XXXVII., figs. 1 e 

 and 1/, and Plate B, fig. 6. 



The metamorphosis of the Tettigid^e is incomplete ; 

 that is to say, both the larvae and the pupae are active ; 

 they each have six legs and eight abdominal segments. 



The larvae and pupas assimilate nomdshment until 

 the disclosure of the perfect insect. Indications of 

 the v^^ings are easily recognised in the larvae, but the 

 wing-cases are more developed in the pupae. Both 

 these stages have considerable resemblances to the 

 imago, but their ocelli and genitalia are more or less 

 in a rudimentary condition. Examples of larvae will 

 be found in Vol. i., Plates XXIII., XXIV., and 

 XXXVIII., and of pup^^ on Plates III. and XXXIII. 

 Immature forms of other species will be drawn also in 

 Vol. ii. 



The males are more brightly coloured than the 

 females ; and, as is usually the case (when the female 

 carries the male), he is the smallest. Apropos to this 

 remark, De Geer says, in their conjunctions the female 

 takes the lead, " et le male la suit, ou plutot il est 

 entraine par elle." The male sex can always be distin- 

 guished by the absence of saw-valves on the under 

 surface. In the Idioceri the antennae of the males 

 are in most species clubbed at the tip. (See Plate 

 XXXL). 



The ripe ova may often, in late summer, be seen in 

 the females, and, for the size of the insects, they are 

 remarkably large. I have measured those of Pediopsis, 

 and they average 0*024 of an inch, or 0-61 millimetre. 

 They are not often numerous within the ovaries of the 

 Tettigidae, for many females only contain three, and in 

 the genus Athysanus, usually only five ova can be 

 counted ready for extrusion. The eggs of some species 

 are of a long-oval form, whilst those of Pediopsis 

 virescens are slightly bent or turned in opposite direc- 

 tions at their polar ends, thus forming in figure a kind 

 of /. The vitelline membranes and numerous oil- 

 globules may in these bodies be readily traced. In 



