126 



Hillside. 



Tortoiseshells are safe until they rise on the wing and 

 display their bright upper sides, owing to the leaf-like 

 appearance they present when at rest. The bright males of 

 the Chalk-hill Blue are taken, their dull, sober-coloured 

 wives more frequently left. Very few of the latter appear 



Fiu. 24. THE SWALLOW (Hirundo rustica). 



to be captured, and we soon understand what a protection 

 their dark coloration must be to that sex, and how skilfully 

 nature provides for the perpetuation of these brightly 

 coloured species, and protects them from utter extermination. 

 A Copper butterfly sits sunning itself on a flower, when a 

 dark shadow falls on it, cast by a passing bird ; immediately 

 the wings are drawn together, and all that remains is a dull 



