27 
and st-misyntjrapita, ineijualis, and other forms quite unusal to these 
localities were taken (equals to which have never fallen to one’s lot 
again). Many $ s were seen with greatly reduced orange crescents, 
and a few with these entirely absent, 2 s and g with gray undersides 
■were not uncommon closely approximating in colour. 
Many a blue marked 5 was discarded that year, parallels to the 
brown fringes and orange crescents were much wanted and could not 
be obtained at all. 
This contrast diametrically opposed in the sexes in these two years 
seemed a paradox, enhanced by 1889, when during most of July and 
August superfestival conditions were present, scarcely a blue scaled 2 was 
to be seen, lightness and brightness in the g s was the prevalent 
tendency and especially with much white detail in borders, more than 
in 1887. 
But when the sexual dimorphism was taken as the key, the whole 
matter was simplified by assuming an influence from the weather on 
the dimorphism, and the decreased dimorphism of 1888, and the 
increased dimorphism of 1887 (in different and less degree) of 1889, 
became reconciled by a theory which has given additional delight to 
all collecting ever since. 
At these same periods the series of Aylaia collected, and those 
observed in the same localities and years with and preceding Cory don, 
were at a glance seen to be apparently influenced on the same lines, by 
the same law, if law it be, especially when comparison was made with 
other collectors. 
In these six series (one each of Corydon and Aylaia, for each of 
the three years, kept separate), a glance was sufficient to show the 
markedly different tendencies of these years and the evidence seemed 
irresistible, as regards the effects on their sexual dimorphism in these 
three years. 
Collected to show, as far as possible, all obtainable forms in each 
year (from observing, as far as possible, all through their seasons, 
every living specimen) and collected without stint to show general 
tendency of each year—the beginning of a specialised collection of these 
two species—and collected without any preconceived theory or bias, 
they were a congeries which one has never been in a position to again 
acquire on same lines. Of these, only just such examples as were striking- 
enough to find a place (temporarily) in an advanced collection, have 
been reclaimable on commencing to collect British Lepidoptera in 1903. 
Thus only scanty examples are furnished in the exhibit. 
The parallelism in Aylaia was briefly as follows:— 
(i) 7 s, 1887.—Melanism common, occasionally excessive (one of 
latter shown). Iridescence marked on very pale ground colour, 
tendency common and (one marked example shown) without melanism. 
This was certainly an increase of sexual dimorphism. 
1888, 2 s.—Two only (and poorly), melanic seen this year (shown), 
otherwise less (rather than more) than usual, sexual dimorphism on 
2 side, many 2 s not all readily distinguishable from g s. Very 
many had the golden brown bases of wings, especially of primaries, 
exactly like g s. 
1889, 2 s.—Again commonly melanic, and late in Aylaia season, 
extremely good examples taken. A few of the paler iridescent 2 
xviii. 
