•378 



BRITISH BUTTERFLIES. 



the imago will probably not appear till the following morning, but it 

 "will equally do so, if the change occurs in the afternoon (Chapman). 



Times of appearance. — The species appears to be, throughout the 

 whole area of its distribution, largely, if rot entirely, double-brooded. 

 In all cases where eggs have been laid in confinement in England, in 

 May-June, the resulting larvae have produced autumnal imagines, but, 

 in some years, e.g., 188H, etc., the later brood has been practically 

 absent, and it is possible that the species, in ■ such years, produces 

 only a very partial second-brood. On the other hand, in favourable 

 years, the second brood may be, and often is, even more abundant 

 than the first brood. In average years the first brood is on the wing 

 from the end of May until early July, and the second brood from the 

 middle of August till the end of September, but, in early years, e.g., 

 1898, the species has been out before the end of April, and the first 

 brood over before the end of May, whilst the second brood has appeared 

 in mid- July and been exhausted before the end of August in the south- 

 east of England; on the other hand, in late years, as in 1903, 1907, and 

 1908, the first brood has continued until mid-July, whilst the late 

 brood, except for single specimens, has not appeared until early 

 "September, but has then continued until mid-October; in the cold wet 

 year of 1888, the scanty first brood occurred in late June and early 

 July, whilst no second brood was seen at all in its usual haunts in Kent, 

 Sussex, etc. In 1898, the first brood, with a very late spring, and that 

 of 1905 with a cold early summer, were exceptionally late, but the 

 second broods well up-to-date owing' to the improved midsummer 

 conditions. The following tabulation by Dr. Hodgson, compared with 

 our other entries for these years (see posted.) may prove interesting : — 



TEAR 



PERIOD OF 1ST BROOD 



IK 



WEEKS 



INTERIM 



PERIOD OF 2ND BROOD 



IN 



WEEKS 



1903 



1904 

 1905 

 1906 

 1907 



1908 



June 2nd (well out)- 



July 8th 

 June 6th-Julv 4th 

 May 27th-July 28th . . 

 May 29th-July 7th . . 

 May 27th-July 23rd . . 

 June 4th (very rare)- 



July ? 



5 



4 

 9 

 6 



8 



?5 



6 weeks 

 6 weeks 

 2 weeks 

 4 weeks 

 4 weeks 



?7 weeks 



August 22nd-Oct. 9th.. 

 August 20th-Sept. 25th 

 August 12th-Sept. 27th 

 August 8th-Sept. 23rd 

 August 24th-Oct. 13th 



August 29th-Oct. 2nd.. 



7 



5 



7 

 7 

 7 



5 



The times of appearance are almost exactly similar in the lowlands of 

 central Europe. In Belgium the species is always double-brooded, 

 the first brood appearing about May 20th, the second in August, and 

 lasting until the end of September (Lambillion). In western France, 

 it also occurs twice in the year, first in May and June, and then in 

 August and September (Oberthiir), April-May and August in the 

 Basses- Alpes (Tutt), May and then August, in the Alpes-Mari times 

 (Tutt), April-May and June-July, in the Bouches-du-Rhone (Siepi), 

 May- June and July-September, in Eure (Dupont), May and September, 

 in Gironde (Trimoulet), May and July- August, in Loir-et-Cher 

 (Chevillon), May- June and August, in Maine-et-Loire (Delahaye), also 

 in Puy-de-D6me (Guillemot), etc. In Switzerland, in the lowlands, 

 it also occurs in two broods, the first in May, and a more numerous 

 one in July-August, becoming, however, gradually single-brooded in 

 the mountains (Frey); one supposes this to be generally true, although 

 •our detailed lists give many dates in April for the first brood in the 



