140 



THE YOUNG NATURALIST. 



[July 



The Thysanoptem embrace a curious group of insects of very minute 

 size, such as the Thripidcz, which occur in great abundance on the 

 flowers of many plants. The wings are microscopic objects of great 

 beauty, are exceedingly transparent, and very narrrow in proportion 

 to their great length. They are, in Thrips cerealium (sp. ?), covered 

 with very short hairs ; and, in addition, the anterior pair have a 

 couple of longitudinal rows of stiffer and more bristle-like processes, 

 one series ol which suffers a marked interruption or break. The 

 posterior wings appear to have a trace of a median nervure, while the 

 outside margins of all four are densely fringed. It is a circumstance 

 of no uncommon occurrence to find apterous females in the different 

 orders, but an exception occurs in that now before us, for it is the males 

 of some species that are found wanting. Mr. Haliday mentions the 

 transformation of the fore- wings into neurated elytra in others. These 

 insects form a highly interesting group, and ought to be great 

 favourites with microscopists. The organs of oviposition in the 

 female are strikingly like those of the Tenthredinida, with a pair of 

 formidable saws: the antennae are likewise worthy of minute examina- 

 tion, each joint being furnished with a pair of digital processes. 



Pass we now on to our second division, which includes the Orthop- 

 tera only, an order containing many familiar insects, including cock- 

 roaches, locusts, crickets, and others. Their upper wings, to which 

 is given the name Tegmince, partake of a few of the characteristics of 

 the hinder pair, being of a nature like unto parchment, rigid, covered 

 with reticulations, and, when laid at rest, the inner portion of one 

 overlaps the corresponding portion of the other. But then this is not 

 an unvarying feature of the order, such not being the case in Mantis, 

 Mantispa, some female Acridoe, Gryllus, and Gvyllotalpa. The tegmina 

 are nevertheless used in flight. The larva and pupa are like the 

 perfect insect, except in the matter of wings, which, though rudimen- 

 tally present, do not become of any real service until the final change. 

 The posterior wings are folded longitudinally like a fan, down the 

 back of the insect, except in Blatta and Phasma, where the anterior 

 surface is somewhat thicker and lies flat, the remaining portion folding 

 under, along the radiating creases formed by the principal nerve 

 branches. In fact, the representatives of the order present a maze of 

 exceptions, and any attempt to compare them by analogy would be 

 hopelessly futile. Thus we find the posterior wings absent, or present 

 to the almost entire exclusion of the upper pair, and though the 

 anterior appendages are represented in all orders, yet a solitary excep- 

 tion occurs in an individual of this group, AscUphasma hieroglyphica, in 



