THE MICROSCOPE AND INSECT LIFE 



Having removed a wing and placed it on the stage 

 of our microscope, we must examine it by reflected 

 light, for it is not transparent. This may be 

 accomplished, if we are using artificial light, by 

 raising the source of illumination well above the 

 object, so that the light strikes it at an angle of 

 about forty-five degrees ; by daylight reflected light 

 is easily managed. If we have never previously 

 examined a similar object we will be surprised at 

 its appearance. All the beautiful reds and blues, 

 yellows and greens which comprise the brilliant 

 livery of these insects are seen, under the micro- 

 scope, as hundreds of minute scales which overlap 

 one another like tiles on a roof. A higher magnifi- 

 cation will show that each scale is roughly flask- 

 shaped, and that its narrow end fits into a little 

 socket in the wing proper. When the scales are 

 rubbed from the wing, nothing remains but a trans- 

 parent substance traversed by veins — to the micro- 

 scopist the scaleless wing is of little interest ; to the 

 entomologist it is important, for the moths, at any- i 

 rate, are arranged into families largely according to ! 

 the arrangement of the veins of their wings. 



Many other wings may be examined with advant- 

 age? gnats, for example, are clothed with scales of 

 varied shape, some hair-like, some forked, some 

 resembling a sickle, and some disc-shaped; these j 

 forms, by the way, do not all occur upon the wings, 

 but are found upon the head and other parts of the I; 

 body as well. The wonderful gauzy, iridescent |i 

 wings of dragon flies are interesting; those ofij 



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