Beautiful Butterflies. 9 



differ considerably in this respect in different species, 

 as the following drawings will show. 



They are fixed to the wing by means of a fine pedicle, 

 or stalk, similar to that of a plant, only so small as not 

 to be seen by the naked eye. It is in these scales that 

 the beautiful colours, which make the wings look like 

 painted velvet, exist ; if you rub them off, nothing but 

 a thin transparent membrane remains ; this is veined 

 all over, much like the skeleton leaves which you may 

 have seen, and these veins no doubt answer the double 

 purpose of canals for conveying nourishment to the 

 frame, and of ribs for giving it mechanical strength. 

 A naturalist named Leiuwenhoek has counted as many 

 as four hundred thousand scales upon the wings of the 

 Silk Moth, and some of our British Butterflies are four 

 times as large as this ; there are foreign Moths which 

 sometimes measure nearly a foot across the wings : 

 think of the number of scales required to cover them. 

 It has been said that " a modern Mosaic picture may 

 contain eight hundred and seventy Tesserulae, or sepa- 

 rate pieces, in one square inch of surface ; but the same 



