CLOUDED YELLOW. 71 



far northwards as the lake district, it there becomes 

 scarce ; and I can find no instance of its having 

 occurred in Scotland. 



Of course, its prevalence in any district is naturally 

 regulated by the abundance of its food-plants, the 

 buckthorns. 



Gardens, fields, and lanes are equally the resort of 

 this favourite insect ; and there the newly-hatched spe- 

 cimens are to be found on the wing from August to 

 October. 



3 . 



THE CLOUDED YELLOW, OK CLOUDED 

 SAFFRON (Colias Edusa.) 



(Plate III. fig. 3, Male ; 3a, Female.) 



This richly-coloured and nimble-winged fly is ever the 

 darling of the collector. None make a finer show in 

 the cabinet, and few tempt pursuit more strongly than 

 does this golden beauty when on the wing. 



For many years past, and up to quite a recent period, 

 the appearance of this butterfly in any abundance was 

 a phenomenon only occurring at uncertain periods, 

 separated by intervals of several years. In one season, 

 perhaps, hardly a solitary specimen would bo seen, and 

 in the very next, a swarm of them would spread over 

 the southern counties, delighting the fly-catcher and 

 puezling the naturalist to find a sufficient reason for 



