THE COMMON BLUE. 165 



I am indebted to Mr. E. Sabine, of Erith, for the loan of all 

 the fine aberrations of the Blues figured on Plate 118. 



On Plate 107 will be found figures of the early stages. 



The egg, which is usually laid on the upper side of a terminal 

 leaf of bird's-foot trefoil {Lotus corniculatus) or on rest-harrow 

 {Ononis spinosa), is whitish-green in colour, netted with glossy 

 white. 



The caterpillar is green, covered with short brownish hairs, 

 with which are mixed some longer ones ; it is wrinkled on the 

 side, ridged on the back, and the line along the middle of the 

 back is darker. Head black and glossy. 



The chrysalis is green, with the head, wing-cases, and some- 

 times the hinder parts of the body, tinged with buff ; thorax 

 brighter green, rather shiny ; a darker line down the centre of 

 the body. 



The plants mentioned, and especially rest-harrow, are known 

 to be the food of the caterpillar, but eggs have also been found, 

 in Scotland, on red clover, plantain, burnet saxifrage, and 

 yarrow. The caterpillars are to be found, after hibernation, in 

 April, and a second brood in June and July. Those feeding on 

 rest-harrow seem to prefer the blossom. 



This caterpillar is stated to form a cocoon, but the only 

 approach to any such structure made by the seven individuals 

 I had under observation was in the case of two caterpillars that 

 pupated among leaves of Lotus, which were drawn together by 

 the slenderest of threads. Four effected the change at the 

 bottom of the cage and seemed to be quite free, one had 

 climbed to the leno top of the cage and there spun a silken 

 carpet under itself, which drew the leno together, and so formed 

 a shallow cave in which the chrysalis rested. In every case the 

 cast skin was attached to the tail, and so remained after the 

 butterflies emerged. 



The butterfly is to be found almost everywhere in the country, 

 and its distribution extends throughout the United Kingdom, 



