INSECTS : "WINGS AND TIIEIR APrENDAGES. 



93 



SCALES OF DIAMOND-BEETLE. 



A piece of one of the "sving-cnses of this beetle is 

 gnnnned to the slide now npon the stai^e. "We look at 

 it by reflected light ■vvith a magnifying power of 130 

 diameters. We see a black gi'ound, on which aio 

 strewn a profusion 

 of Avliat look like 

 precious stones blaz- 

 .ing in tiie most gor- 

 geous lustre. To- 

 pazes, sapphires, 

 amethysts, rubies, 

 emeralds seem here 

 sown broadcast; and 

 yet not wholly with- 

 out regularity, for 

 there are broad 



bands of the deep black surface, where there are no 

 gems, and, though at considerable diversity of angle, 

 they do all point with more or less precision in one 

 direction, viz. that of the bands. 



These gems are flat transparent scales, very regu- 

 larly oval in form, for one end is rather more pointed 

 than the other ; there is no appearance of a footstalk, 

 and by what means they adhere, I knoAV not ; they are 

 evidently attached in some manner by the smaller ex- 

 tremity to the velvety black surface of the Aving-case. 

 The gorgeous colours seem dependent in. some measure 

 on the reflection of light from their polished surface, 

 and to vary according to the angle at which it is re- 

 flected. Green, yellow, and orange hues predominate ; 

 crimson, violet, and blue are rare, except upon the long 

 and narrow scales that border the suture of the wing- 

 cases, where these colours are the chief reflected. Yet 



