38 VIGNETTES FROM NATURE. 



hovering about flowers or rising in the air- to 

 pirouette and gambol with their mates, they 

 run comparatively little risk from the birds. 

 They are too nimble for their pursuers, and 

 they seem fairly secure by their power of 

 doubling as they flit rapidly along from spray 

 to spray. The birds are bad marksmen at a 

 moving target ; they cannot double like their 

 prey, and they prefer to aim at their butter- 

 flies sitting, as French sportsmen are said to 

 do at partridges. On the other hand, with 

 butterflies as with men, faint heart never won 

 fair lady. If the insects did not venture out 

 into the open to seek their mates and to 

 charm them with their painted pinions, some 

 bolder rivals would carry off the prize, and 

 so leave the cowards unrepresented in future 

 ages. Thus, in the course of generations, a 

 great many butterflies have come to have 

 two sets of colours the one set attractive 

 for their own kind, and the other set protec- 

 tive against their enemies. The lower sides 

 of the wings are coloured like the leaves or 



