INSECTS. 



243 



FIG. 



ORDER L--THYSANURA. 



These are small wingless insects without any general 

 common name except those of 'bristle- 

 tails ' and ' springtails, ' which have been 

 manufactured for them. The springtails 

 live in damp places in cellars, under 

 leaves in the forest, etc., and they have 

 a spring beneath the body by means of 

 which they can jump to great distances. 

 The bristletails have the body terminating 

 in two long filaments. To this last group 

 belong some pests known commonly as 

 ' silverfish ' -soft-bodied shining forms, 

 which eat paper, starched clothing, etc. 

 Aside from this silverfish or 'fish-moth' 

 the group has little general interest; but 

 to the naturalist it is very interesting 

 because it is so primitive. 



ORDER II. ORTHOPTERA. 



The name Orthoptera, which is given to the group 

 containing the grasshoppers, crickets, locusts, cockroaches, 

 etc., means straight- winged, and alludes to the general 

 course of the veins of the wings of most forms. This is, 

 however, not a feature of great importance, for indeed we 

 find species which are absolutely lacking in wings, but 

 which are, in other respects, so closely related to the 

 grasshoppers that they too must be included in the Orthop- 

 tera. When we take all of these Orthopterous forms we 

 see that they agree in a number of points, some of which 

 may be mentioned. The jaws are strong and fitted for 

 biting hard substances; the antennae are usually long and 



68. 'Silver- 

 fish' (Lepisma 

 saccharina). 



