160 LIFE, IN ITS INTERMEDIATE FORMS. 



pattern of the touched part in all its beauty. Now by 

 touching with the charged finger-end a strip of glass, and 

 placing this latter beneath a microscope, we discover an 

 extraordinary specimen of the Divine handiwork. Plun- 

 dreds of objects are left adhering to the glass plate, which 

 we know not whether to call scales or feathers. They dis- 

 play considerable variety of form, but the most common 

 is oval, or semi-oval, with a little projecting stem or quill 

 at one end. They are thin and flat, transparent and mem- 

 branous in texture, with several ribs running lengthwise, 

 the points of which project beyond the end of the scale. 



These scales, then, produce the beautiful party-coloured 

 patterns of a Butterfly's wing ; but of positive colour 

 they possess individually no trace under the microscope, 

 save a dull smoky appearance. It is by the separation 

 and reflection of the prismatic hues that they appear beau- 

 tiful, but by what law some reflect none but red, some 

 none but yellow, some none but blue rays, we know not. 



On examining the wing that has been denuded of its 

 coloured scales, we see a transparent, dry, brittle mem- 

 brane, pitted with innumerable punctures arranged in 

 lines ; these are the depressions in which the stems of the 

 scales were originally planted. They were so ordered that 

 the extremity of one scale reposed on the base of its suc- 

 cessor, overlapping and concealing its stem, so that the 

 arrangement resembled that of tiles or slates on a roof. 

 We have said they are innumerable • the expression is 

 not literally exact, but you will think it excusable when 

 you hear that Leeuwenhoek computed the number of 

 scales on a Silkworm Moth (Bombyx mori), to exce^ 

 400,000 ■ and those which bespangle the wings of the 



