16 BRITISH BUTTERFLIES. 



the wing of the Peacock, a very beautiful, though an 

 abundant species, and one admirably adapted for 

 microscopic examination, and to illustrate the subject, 

 from the great variety of rich tints brought together in 

 a small space, the part selected being the eye-like spot 

 at the outer corner of each upper wing. Even to the 

 naked eye this appears as a very splendidly coloured 

 object, yet but little of its exquisite mechanism can be 

 discovered by the unassisted organ. Something more 

 is brought out by a moderately strong lens : we then 

 see the colours disposed in rows, reminding us of the 

 surface of Brussels carpet, or of certain kinds of 

 tapestry work. 



Now let us place the wing on the stage of a good 

 microscope, with the root of the wing pointing towards 

 the light (that is the best position for it) ; we shall then 

 first perceive that the whole surface is covered, or, so to 

 speak, tiled over with distinct, sharply cut scales, arranged 

 as in fig. 16, Plate II., with the outer or free edges of 

 one row overlapping the roots of the next. These roots 

 being all planted towards the base of the wing, if we 

 place that end next the light (as above directed), the 

 free edges of the scales throw a strong shadow on the 

 next row, which brings out the imbricated effect most 

 strikingly. 



Beginning our observations at the outer edge of the 

 wing, we first notice a delicate fringe of scales or plumes, 

 more elongated and pointed than the surface scales, and 

 of a quiet brown colour. This tint is continued inwards 

 for a short space, gradually lightening, when (as we 

 shift the field of view towards the centre of the wing) 

 the colour of the scales suddenly changes to an intense 

 black ; then a little further, and the black ground is all 

 spangled with glittering sapphires, then strewed deep 

 with amethyst round a heap of whitest pearls. Golden 

 topaz (jewels only will furnish apt terms of comparison 

 for these insect gems) golden topaz ends the bright 

 many-coloured crescent, and in the centre is enclosed a 

 spot of profoundest black, gradating into a rich un- 



