90 Objects for the Microscope. 



branched. They all have long and beautiful antennae, 

 which, in the males, are plumed and whorled like the stems 

 of Equisetum. 



The wings are narrow and lanceolate. 



Sub-costal vein ends a little before the tip of the wing. 



Radial, branched from the Sub-costal, and is forked. 



Cubital vein begins from the Prcebracliial small transvese. 



Mediastinal is between the Radial and Costal. 



Prccbrachial is also forked. There are fourteen areolets. 



The scales of a Gnat form test objects of the defining 

 power of an object glass. Scales are composed of two or 

 three layers of membrane, and probably the longitudinal 

 ridges in these scales may represent folds of the outer 

 membrane. We should not only see these striaj, but the 

 delicate transverse markings and projections of the lines 

 beyond the top of the scale. 



Gnats fly silently in winter and early spring, before the 

 thirst for blood is awakened, and then the female only sounds 

 the shrill clarion of war in her eager flight to and fro. See 

 the Gnat (Culex), mounted whole, and for the complete 

 knowledge of Flies, consult ' Walker's British Diptera,' 

 vol. iii. ; ' The Insecta Britannica.' 



WING OF COLEOPTERA. 



Beetles have four wings ; but the upper pair, being crusta- 

 ceous and used only as a protection for the under pair, are 

 called Elytra. Their use is obvious from the habits of the 

 Coleoptera ; they burrow in the ground and reside under 

 the bark of trees, or beneath stones, when the undefended 

 membranous wing would receive the greatest injury. The 

 under wing is particularly described when examining the 

 slide of Telephorus. 



Both of these should be mounted and observed. The 

 upper pair, or Elytra, if properly prepared, are very beau- 

 tiful polariscope objects, especially those of Dytiscus and 

 Cockchafer (Melolontha). 



But there is a more important notice to be taken of the 

 internal structure of the Elytron. Dr. Hicks discovered 

 the same vesicles here as he did in the antennae of Flies 



