132 London Insects. 



human invention, and that there is no such thing as a 

 hard-and-fast line anywhere in Nature, where all is 

 gradual. We can find out without much difficulty 

 when the gas lamps are lighted they are human 

 institutions, but it would puzzle the wisest of us to 

 say exactly when it is that the " crimson streak" on 

 the Serpentine " grows into the great sun." No wings, 

 two wings, and four wings are, we can see, the general 

 characteristics of large classes, but at what precise 

 spot the separating lines are to be drawn on paper 

 must be, to a great extent, a matter of fancy. They 

 may be, in most cases, moved up or down without its 

 mattering very much. As already mentioned, among 

 the wingless insects is a class the " Aphaniptera " 

 which has " scales representing rudimentary wings." 

 Most of the " two wings " have a rudimentary second 

 pair, known as " balancers," behind their more perfect 

 first wings, and a whole order taking rank among the 

 four wings the " Strepsiptera " have nothing better 

 to show, as front wings, than the miserable little 

 " screwed up " apologies which give the order its 

 name. 



Unfortunately, however much we may have cause 

 to lament the scarcity of the more showy Butterflies 

 in London, we cannot complain of any want of speci- 

 mens of the first great order of insects, the "wingless." 

 There are three classes of the order, all most objec- 

 tionable, and the less said about any of them, perhaps, 

 the better. The class, already referred to, which, 

 having little scales to mark where wings should be 

 connects the order with the flying insects, is certainly 

 not the worst. 



Its most familiar species is the Flea. Bad as it is, 

 with its " double lancet mouth," in one respect the 

 Flea ranks high in the moral scale. 



