INSECTS : WINGS AND THEIE APPENDAGES. 



91 



FKIKGED SCALE OF 

 riERie. 



that the fringe is arranged. The surface does not ap- 

 pear to be elevated in ribs, but smooth ; while tlie whole 

 interior, except a crescent around the 

 foot-stalk, is filled with pigment-grains, 

 imparting a mottled appearance. It is 

 remarkable that all the scales of this form 

 have the foot-stalk turned in under the 

 expanse. The example which we are 

 considering is from the white portion of 

 the wing of Pieris Olaucvppe, a fine but- 

 terfly from China ; but a similar struc- 

 ture is found in our own Garden Whites, 

 and Meadow Browns, {Pieridm and 

 ScUyridoB). 



Scales taken from the brilliant 

 changeable blue-green patch in the hind- 

 wing of Pa/pilio Paris, a fine Indian 

 butterfly, have an interesting appearance. They are 

 simply pear-shaped in outline, ^with few longitudinal 

 ribs set far apart, and numerous strongly-marked cor- 

 rugations running across between them. That these 

 are really elevations of the surface, is well seen in some 

 scales, even with transmitted light, and a high power ; 

 for the slopes of the wrinkles that face the light display 

 the lustrous emerald reflection proper to the wing, 

 while the transmitted colour of the whole scale is a rich 

 transparent red. 



The dimensions of the scales do not bear any 

 certain proportion to the size of the insect which is 

 clothed with them ; those from the broad wings of 

 the noble Sahornia Atlas, for example, eight or nine 

 inches in expanse, being exceeded in size by some 

 from those of our little native Muslin Moth, an inch wide. 



