84 THE MICROSCOPE. 



at intervals, each with a black point in its centre. 

 The metallic lustre of the scales of the diamond 

 beetle -of South America (Curculio imperialis) will 

 astonish you from its gorgeous magnificence. I have 

 a specimen before me as I write, but I cannot de- 

 scribe it better than in the words of Mr. Gosse. " We 

 look at it by reflected light, with a magnifying power 

 of 130 diameters. We see a black ground on which 

 are shown a profusion of what look like precious 

 stones, blazing in the most gorgeous lustre. Topazes, 

 sapphires, ametl.ysts, rubies, emeralds seem here sown 

 broadcast, and yet not wholly without 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 regularly oval in form, 

 for one end is rather more pointed than the other ; 

 there is no appearance of a foot-stalk, and by what 

 means they adhere I know not. They are evidently 

 attached in some manner by the smaller extremity to 

 the velvety black surface of the wing-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 reflected. 

 Green, yellow, and orange hues predominate ; crim- 

 son, 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."* 

 Mr. Gosse, however, thinks there is some positive 

 colour in their substance. 



The scales of fish, the feathers of birds, the hairs of 

 insects, insect-larvae, and mammalia, will afford you 

 matter for contemplation and study. Scales of fish 



* " Evenings at the Microscope," page 99. 



