100 



EVENINGS AT THE MICROSCOPE 



is more interesting, you can trace the manner in which 

 they are set those of each row slightly overlapping the 

 bases of another row, like slates on a roof and also the 

 mode in which they are inserted. The clear horn-colored 

 membrane of the wing is seen raised in shallow transverse 

 steps (if I may use such a term) so that if it were divided 

 longitudinally, the edge would appear cut into saw-like 

 teeth. Along the margins of these ridges are set minute 

 sockets, which are very distinctly seen, where the scales 



have been displaced: in 

 these the tiny foot- stalks 

 of the scales are inserted. 

 The little Beetles which 

 we are familiar with un- 

 der the name of Weevils, 

 characterized by their 

 long slender snouts, at the 

 end of which they carry 

 curiously folding anten- 

 nae, and which constitute the family Curculionidm, are in 

 many cases clothed with scales, to which they owe their 

 colors and patterns. Several of our native species display a 

 green or silvery lustre, which under the microscope is seen 

 to be produced by oval scales. But these are eclipsed by 

 the splendor of many tropical species; especially that well- 

 known one from South America, which is called the Dia- 

 mond Beetle, and scientifically Entimus imperialis, from 

 its unparalleled magnificence. 



A piece of one of the wing-cases of this beetle is 

 gummed to the slide now upon the stage. We look at it 

 by reflected light with a magnifying power of 130 diam- 

 eters. We see a black ground, on which are strewn a pro- 



SCALES OF DIAMOND-BEETLE. 



