AN INTRODUCTION TO K \TOMOLOGY. 



dorsal aspect of the nu-so. and mctathoi.>\. These In-come la: 

 and moult, assuming the form of pad- 



FIG. u.-Ny 



ui, fifth kUge. 



-4/*Ai *///, adult. 



like wing-cases. But these wing-cases never approximate in length 

 the perfect wings of insects in which these or-. ins become fully 

 developed. Tluiv is. therefore, usually a very marked change 

 between the last nymph stage and the mature in- 

 u and 13.) 



With the nymphs of certain families, dragon-flies, cricke: 

 hoppers, and locusts, the wir. are inverted : i.e., the aspect cor- 



responding to the upper side of the wing is next to the body, and 

 the first pair of wing-cases extend back beneath the second pair. 

 This characteristic is useful in distinguishing the adult forms from 

 the nymphs of those species in which the wings never become fully 

 developed. 



