284 LEPIDOPTERA. 



J. Harrison of Barnsley, and, as it was a female, he tried the 

 experiment of pairing it with a male of the strongly marked 

 Yorkshire form, with normal markings. The result was 

 satisfactory — a series varying from the extreme (^radiata) 

 black and rayed variety, through the more strongly marked, to 

 ordinary and typical specimens. By selection in breeding 

 he, to a great extent, eliminated the ordinary forms, and 

 obtained a breed of pure o^adiata. Eggs from these forwarded 

 to Mr. W. H. Tugwell furnished grand results, the variety 

 not only breeding freely, and purely, but increasing in size, 

 and also producing a full second generation in the year. 

 Very beautiful specimens have been provided, by both gentle- 

 men, for the purposes of this work. Outside these well- 

 ascertained forms variation is slight ; Mr. S. J. Capper has a 

 white female from Cheshire, wholly devoid of markings ; and 

 others with the fore wings immaculate. Specimens in many 

 collections in which black lines or stripes run along the costal 

 and dorsal margins, or with the markings elongated into 

 short streaks and bars, are merely advances towards the 

 extreme variety already noticed. 



On the wing in June. Occasionally a second generation 

 is reared, in confinement, in the autumn. 



Larva rather even in thickness; head round, brown ; mouth 

 black ; body greyish brown, densely covered with hairs, which 

 are reddish brown, rather even in length ; dorsal line pale 

 reddish, very faintly indicated ; a broad dirty yellow spira- 

 cular stripe occupies the lower portion of the sides down to 

 the legs; spiracles white ; legs yellowish brown. When very 

 young uniformly pale yellowish ; as it grows it becomes 

 greyish, and gradually brownish, with the hairs pale, short and 

 bristly, and the spiracular line white. Always very smoothly 

 nimble and active in its movements — hence its name. 



July to September, on low-growing plants. Especially 

 attached to gardens ; feeding mainly on weeds but not dis- 

 daining any herbaceous plant, often most destructive to ferns 



