OF ARTS AND SCIENCES. 155 



moreover, is a feature of the males alone, and occurs in many hair- 

 streaks wliere the position of the veins is not altered. 



One of the most curious patches of tliis kind is found in the males 

 of some species of Eurymus, althouj^h wholly absent from others inti- 

 mately allied to them. It is a little patch of lustreless scales, which 

 occurs at that part of the base of the hind wings which is always cov- 

 ered by the front wings, so that it is quite concealed from sight. 

 Patches of a different nature also mark the male sex ; thus, next the 

 middle of the lower median vein of the hind wing of Danaida Plexip- 

 pus (Linn.), and in some of its allies, we have a heavy thickening of 

 the membrane, conspicuous from its covering of black scales. 



In very many males of the larger Skippers {Hesperides), the front 

 edge of the fore wing is abnormally expanded, and folded compactly 

 upon the upper face of the wing, so snugly that often it can oidy be 

 discovered with the lens; moreover tlie scales within this have turned 

 to white silken floss, which, when the fold is raised, contrast conspicu- 

 ously with tiie ordinarily dark surface of this part of the wing. In 

 certain Swallow-tails (E(/m'tes) also, the inner border of the hind wings 

 is folded back in a similar, though looser, manner ; but is so much lar- 

 ger that, when opened, it often exposes a white downy surface as large 

 as the abdomen. 



Then again there is much variety of male adornment in special mod- 

 ifications of hairs or scales upon ihe wings. The patch of tiie hair- 

 streaks already mentioned is one instance of this; another example 

 is found among the Dryadcs, in a row of long, fulvous, partially erect 

 hairs along the upper edge of the cell of the hind wings ; this is accom- 

 panied by a curious apparent thickening of the veins in tlie middle of 

 the fore wing, due altogether to the presence of a multitude of small 

 and densely clustered black scales, crowded against the veins at this 

 point. A faint oblique ])atch of minute and crowded lustreless scales, 

 accompanied by long silky hairs, is often seen crossing the wings of 

 some of the Satyrids ; but this feature finds fullest expression iu the 

 Astyci, or smaller Skippers, where a large proportion of males liave a 

 patch or oblique dash of peculiar scales covering veins and membrane 

 indiscriminately, but usually, and in our native butterflies ahvaj^s, occu- 

 pying the middle of the front wing, and crossing the median veins 

 obliquely near their base. This dash is variously formed, but the 

 scales which compose it are much larger than the ordinai-y scales, are 

 black, and frequently partially erect. They may also differ in various 

 parts of the patch itself, and alter its character abruptly ; for in- 

 stance, some comparatively huge and brilliant scales may occupy the 



