178 HOP AND CURRANT APHIS. 



which these peaceful armies carry in their wake. The leaf, 

 whose surface, when they take it in possession, resembles a 

 smooth green plain, or, divided by intersecting veins, a country 

 of verdant fields, is presently warped and converted into barren 

 hills and arid dales by the extraction of its fertilizing sap; 

 while the tender bud and vigorous shoot, though differently, 

 are equally distorted and desiccated by their operations. 



For the most part, these Insect marauders, living to eat and 

 to be eaten, seem to have no other business, no thought or 

 care, except on the matter of supplies, and take no trouble to 

 conceal their ranks from the observation of their numerous 

 enemies, or even to shelter themselves from the stormy wind 

 and rain which sweep them off by millions. That well-known 

 />////// ter of the hopes of hop-growers (in common parlance 

 \rlrpt "the Fly," albeit generally wingless) is an open ravager 

 of this description, feeding sometimes on the upper, sometimes 

 on the under ?idr of the leaf. But to this general rule there 

 are numerous exceptions, and a familiar instance of their 

 defensive works is to be met with on every Aphis-blighted 

 currant bush. Take one of those leaves so often seen bloated 

 by raised blister-spots of brownish red, examine their answering 

 concavities beneath, and within these snug recesses you will 

 intrude on as many social groups of Aphides, using their pipes 

 in each separate divan. 



Some other species, common on poplar, lime, &c., are pro- 

 vided with places of assembly, habitation, and concealment, of 



