52 INSECTS. 



writers these parallel lines are supposed to be tubes ; 

 and let the reader imagine, if he can, the size of a tube 

 of which a large number are found in a single grain 

 of dust on a butterfly's wing ! Of these scales, or 

 grains of dust, Leuwenhoeck computed the number on 

 the wing of a single moth to exceed 400,000. 



For figures of Order VIII., Lepidoptera, see Plates 

 X., XI. 



With the Lepidoptera we enter on a division of in- 

 sects which differ in one important respect from those 

 which have been already mentioned, and which possess 

 biting jaws. In Lepidoptera (moths and butterflies) the 

 character of the mouth is entirely changed, and these, 

 and all the following orders, may be classed as insects 

 which live by suction. The structure of both kinds of 

 mouth has been described in the second chapter. 



The moths and butterflies then, compose the first order 

 of the sucking tribes ; the second is that which comprises 

 the cicada, cuckoo spit, aphis, &c. 



These have two pairs of wings, which in cicada, aphis, 

 and others, are all alike clear and membranous ; while in 

 the froghopper and others the front pair is more or less 

 thickened, somewhat like those of the grasshopper. This 

 is the only order in which the beginner could make a 

 mistake. Attending only to the slight description given 

 here of the wings and wing-cases, he might refer some of 

 the clear-winged insects to Hymenoptera, and others with 

 thickened fore-wings to Orthoptera ; but it must never be 

 forgotten that the Hymenopterous and Orthopterous in- 

 sects are biters, whereas these are sucking insects, without 

 horny mandibles, and usually provided with a long 

 tubular beak, sufficiently conspicuous to distinguish them 

 with ease. These insects belong to the order Homoptera 

 alike; irrspov, wing), so called because, 



