THE DIAMOND BEETLE. 207 



black, but have a number of oval marks on them. These marks 

 are green-gold, similar to the colour of the thorax, and between 

 several of them are two or three deep circular punctures. 



The best known of these insects is the celebrated Diamond 

 Beetle (Eniimus impcrialii), also a native of Brazil. This 

 Beetle, magnificent as it is when the microscope is brought to 

 bear upon it, is not to the unaided eye nearly so beautiful as 

 many insects which are not so splendidly adorned. The elytra 

 of this insect are black, and upon them are many parallel 

 circular spots, each about as large as a pin's prick. To the 

 unaided eye these spots are glittering green, but when the 

 microscope is brought to bear on them their true beauty is 

 disclosed. 



Each of these is a shallow, circular pit, set thickly with scales, 

 which are arranged something like the tiles of a house, one pro- 

 jecting over another. These scales are mostly green, but each 

 of them possesses many colours as the light happens to change. 

 One of these scales in the specimen now before me is entirely 

 shining gold, while its immediate neighbour is gold in the centre 

 warming into orange on its tips, and has at the base a patch of 

 crimson on one side and azure on the other. The next scale has 

 the basal half of a rich shining ruddy gold, and the other half 

 deep purple. The next scale is entirely emerald green, so that 

 the little shallow pits look as if studded with leaf-shaped gems, 

 no two being of precisely the same colour. 



If even the direction of the light be changed, the colours 

 change with it, the green shifting gradually into gold, blue, 

 purple, orange, and crimson, just like the changing flashes of 

 a good brilliant. Generally, but not always, a small space at 

 the bottom of the pit is devoid of scales, its dead blackness 

 producing a remarkable contrast with the dazzling brilliancy 

 around it. These gem-like scales are but loosely attached to 

 the surface, so that they can be easily removed and examined 

 under a high power of the microscope, either as transparent or 

 opaque objects, the latter being the best plan for bringing out 

 their beauties, provided that a sufficiency of oblique light can be 

 thrown upon them. The whole of the body is adorned with 

 similar scales, though nowhere are they so large or so beautiful 

 as on the elvtra. 



