25 
different races, e.g., Lancashire and Surrey 2 Argus (iEgon), as show¬ 
ing the influence of particular seasons. 
Proviso iv.—That one be prepared to consider certainly a large part 
of larval state as well as pupal, and period of change into, and out of 
latter state, with regard to influence of weather, etc. 
It must be confessed that this has not been hitherto considered in 
observations forming basis of these notes. 
Proviso v.—One submits, also, that (beyond merely acceding to first 
proviso as to making use of the whole generation for estimating the 
sexual dimorphism) the judgment will probably be made not so much 
from extreme variations, when isolated, or almost isolated specimens, 
as from the abundant middle classes. For, for example, in a locality 
where usually exists but little tendency in Corydon to blue in 2 s, one 
ab. Synyrapha might duly be regarded as of less moment in one year, 
than in another year 30 J s with blue scaling above the local average, 
although all 30 might be much inferior to synyrapha blueness, when 
these are used as data for judging the sexual dimorphism of the 
respective years of their occurrence. 
This is, of course, pure supposition, for that in such a locality 
synyrapha could occur, unless in a season markedly subaestival, and 
then occur alone without other blue (more or less) examples of 2 , has, 
I think, yet to be proved. 
One argues that this consideration of the “middle classes” or 
estimation of the average, is justifiable, indeed requisite in this con¬ 
nection, because it is not probable that no other conditions (but only 
a subaestival summer) will result in any of such aberrations as are here 
believed to be associated with weather, etc. Such argument is not, 
for one moment, offered even by the proposition, since many variations, 
it is known, which seem to be connected in some localities with 
climate, are usual or exclusive forms or races in others, e.y., abs. 
synyrapha, valesina, etc. 
It is held reasonable to consider mainly the abundant middle 
classes, because at any rate, a few well-marked aberrations may well 
be caused by other agencies; whereas the more general (in varying 
degrees) a variation appeal’s in a brood, the more fairly one judges 
this may be put down to general conditions acting on the whole brood ; 
and further, the more general a variation is found to be in separate 
localities, still the more fairly with similar conditions may these 
similar general conditions be held responsible for an unusual variation, 
or unusual extent of such, responsible at least as a contributive cause, 
acting on all individuals indiscriminately ; although each individual 
may or will reach each in its own manner, and to its individual extent, 
and these may be in some a manner or extent scarcely, or not at all, 
appreciable. 
From some facts observed in one year, 1907, two single examples 
may suffice as show’ing the importance of observing these provisos. 
i. In the first brood of bellaryns the $ s were extremely constant 
about an average colour of a middle tint of not intense blue, not 
inclining to greens nor strongly to violet. They were withal lacking- 
in brilliance, dulness being the great characteristic for 1907 $’s first 
brood. Only at end of second week of flight, during eight and ten 
days, were quite a few less dull specimens found, and one of these 
xviii. 
