28 
(absent in 1880 apparently) seen, and several specimens taken with 
ground colour of an extremely dark rich brown colour, not taken in 
any other year (shown). 
(ii) $ , 1887.—Very brilliant, often lightly marked, undersides 
commonly olive, not green. Increased sexual dimorphism. 
1888, S s.—Perhaps darker than usual, especially and certainly 
bases of primaries. 
1889, S s.— Much less olive than 1887, but mostly less green than 
usual. 
These then are examples of years in which both Corn Jon and A ala i a 
both on 7 and on $ sides showed undoubtedly increased sexual dimorph¬ 
ism in two superjestival summers, between which came a subaestival 
summer with decrease of sexual dimorphism. In each year since then, 
so far as collecting has been contined in England, this theory has 
suffered no important contradiction by observations or from subsequent 
collecting, rather the reverse. While the superfestival summer of 
1906, and subfestival one of 1907 have afforded many instances of 
similar coincidences. 
In 1906, the $ Aylaias with brilliant uppersides, with undersides 
more olive than usual, or with green markings greatly reduced on 
yellow grounds, were common. Dark melanic $ s (in cases fairly fully 
melanic on primaries) with undersides showing deep green in excess, 
and tendency to increased black edging of pearly markings (with the 
exception of fully melanic were of repeated occurrence, and made for 
increase of sexual dimorphism). 
And the subfestival 1907 brought (in one’s own experience) such 
Aylaias that one could not prevent one’s attention being diverted from 
them on the slightest excuse, in two of the three localities habitually 
visited for them (the third was not habitually visited in 1907). 
Similarly with Corydon ; in 1906, Js with blue scaling were 
scarcely obtainable, one specimen only retained, after a very fair 
amount of observation of this species; while in 1907 (the subfestival) 
one discarded many an inferior blue-scaled $ , and retained more blue 
2 s than one had seen in all the other six years mentioned taken 
together since 1888, viz., 1889, 1890. 1897, 1903, 1901, 1905, 1906. 
In the last years, again, 1906 and 1907, still more noticeable was 
the case of A. bellaryus. For the last five years in all localities visited, 
beside a tendency to striate and obsolete aberrations, there has been a 
strong tendency to blue in the 2 s, and to, at any rate in some localities, 
some darkness of 2 s. That is in Sussex, Surrey and Kent. Except 
as regards East Kent in relation to blue 2 s and ab. obsoleta, this was 
a very different experience to one’s collecting in years previous to 1898. 
In 1905, well-marked specimens of 2 s with blue were obtained 
(though the species was not mostly common) in excess of any from 
previous collecting ; this was in first brood. A few also unusually blue 
(for second brood) were seen in September. 
In 1906, the tendency was markedly less, and the distinctive 
features of 1906 broods were brownness and blackness (sometimes 
intense) of 2 s, and generous display of upperside marginal orange 
spots, especially in second brood. But after mid-September a few 
good blue 2 s were taken—one, the bluest of 1906 seen, was taken on 
xviii. 
