316 INSECTS ON THE THISTLE. 



also a purple couch whereupon at drowsy evening, as in the 

 fading time of year, we are sure almost to catch him napping. 

 When the purple of the flowers has faded also, the head of a 

 thistle remains still a tower of strength, for defence not alone 

 of vegetable life : sometimes its bristling out-works may pro- 

 tect only its own seeds, but most often they enclose also an 

 insect garrison, to which this bitter corn supplies provisions. 

 Minute grubs and tiny caterpillars, bright scarlet and brownish 

 white, thus live -by thousands within the prickly calyx, till in 

 lieu of the seed and its feathery down, devoured and arrested, 

 they themselves are seen floating through the air in the winged 

 forms of downy Moth or glittering Ely. 



For the most part, the wings of both sexes among Butterflies 

 are adorned alike, but sometimes, as with the feathered race, 

 there is a difference clearly not to the lady's advantage, in the 

 painting of her pigmy plumes. The pretty Orange-Tip,* that 

 well-known sporter amidst sylvan glades and meadows, has at 

 home occasionally beside him a white-winged partner, bearing 

 his name, but without a colour of pretension to the title. The 

 brilliant blue of our little Argus, of fighting celebrity, is deepened 

 in his lady to a purplish brown ; while the bright yellow of the 

 Brimstone beauf fades in his modest belle to a greenish white. 

 Linnreus not aware, it is supposed, of this occasional difference 

 of colour in the opposite sexes of Butterflies, has sometimes 

 strangely put asunder what nature joins together, representing, 



* Pontia carJamines. t Gonapterix rhamni. 



