FORFICULODEA. 



and we gather that the insects have changed little in 



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appearance, size, wing-form, and wing-expanse. The 

 callipers, however, seem to have been decidedly less 

 conspicuous than at present. 



We may describe the Earwigs as : Injects irifh 

 slight post-embryonic development, the nymphs being renj 

 similar to the imagines. The hind femora are suitable 

 for running, the tarsi being of 3 segments usually u'ltlnmt 

 pulvillus. They are mute, stridulating organs being 

 absent. Their bodies are elongate, the arrange HI cut of 

 the segments of the abdomen being imbricate ami the 

 abdomen being terminated by cerci, which tal'e the form 

 of callipers. The elytra are leather-like and much 

 smaller than the vings, these latter being folded from 

 tin' baxc en n1 again at the middle of the 'anterior margin ; 

 many species, however, are wingless. Ocelli are absent. 



In the male the number of segments of the abdomen 



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is ten, whereas in the female there are but eight, the 

 8th and 9th segments being aborted and practically 

 absent. In many earwigs, on the 4th segment at 



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least, may be seen on each side a fold of the skin con- 

 nected with scent-glands. The number of segments 

 of the antennae varies from about ten to fifty, and this 

 is an important point in connection with classification. 

 Other points are the shape of the second tarsal segment, 

 of the pygidium (a small organ between the branches of 

 the callipers), of the sub-anal plate, and of the segment 

 preceding it. There is a small apical segment to the 

 palpi, which seems to be peculiar to the Forficulodea. 

 No doubt the callipers (or forceps, or pincers) are 

 the features of an Earwig which appeal first to an 

 ordinary observer, and to the naturalist they are of 



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interest on account of the history of their descent, and 



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the uses to which they are put. There seems to be no 

 doubt that thev are homologous with the cerci of 



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Campodea, the Cockroaches, and some other insects, 

 but that they have been modified for special purposes. 

 The question as to what these purposes are has given 

 rise to some little discussion, and the discrepancies in 



