310 LEFIDOPTERA. 



one in N^hicli the stripe is dark purple and throws out clouds 

 of the same colour toward the second line ; the continued 

 stripe on the hind wings is also purple. Another specimen 

 in that collection has a brilliant red cloud in the middle 

 of each foi'e ^ving. A more permanent variation occurs in 

 the second generation, the central stripe in it being scarcely 

 so strongly marked, and the specimens themselves usually 

 rather smaller, but their beauty is enhanced by the presence 

 of a row of small purple-brown or purple-grey clouds outside 

 the second line. Mr. F. Merrifield, in the course of his ex- 

 periments upon pupa^, found that in all the pupa3 which he 

 could force out in the same season — as a second generation — 

 these purplish clouds were present, but that those of the 

 same brood kept through the winter produced moths of the 

 normal colouring ; and also that if he produced an artificial 

 winter by means of ice. and exposed such pupfe to it, after- 

 wards bringing out the moths before the winter, the same 

 spring form was produced. Those, on the other hand, which 

 he forced out most rapidly showed a tendency to distinctness 

 of all the transverse lines as well as of the purple clouds. 



On the wing at the end of May and in June ; and in a 

 partial but constant second generation at the end of July, 

 and in August. 



Larva slightly swollen at each end, but especially behind ; 

 head rather quadrate, the angles rounded, pale green, with a 

 brownish shade in the middle of each lobe, and two indistinct 

 yellowish lines half across the face ; general colour either 

 tawny or bright emerald green ; dorsal line IJack, conspicu- 

 ous at each extremity, and forming a triangular blotch on 

 the anal segments ; spiracular lines dark ])urple-brown or 

 black-brown ; a black marking of a horseshoe shape bisects 

 the dorsal line, and joins the spiracular lines, on each segment 

 from the fifth to the tenth ; these markings are very con- 

 spicuously and broadly edged below with pale yellow ; legs 

 and proiegs red-brown; undersurface pink or rose colour, 



