31 
In 1007 there appeared much commoner than usual green $ s, and 
both $ s and $ s were greener and much darker often, and even 
brownish with black edging to white (“pearl”) spots, and even black 
dusting on disc ; and these, which were both extremes and came close 
together, recurred again and again well into September. Thus by 
sequent variation in $ s average dimorphism of the sexes was greatly 
reduced in this particular in subfestival 1907. 
10. And one instance possibly from opposite season. Possibly in V. 
napi similarly summer emergence form of undersides of secondaries 
was closely approximated in three seasons by both 5 s and J s of Napi, 
and the sexual dimorphism seemed to be diminished. This, by pro¬ 
tection from all exposure and from cold of pupae remaining over 
winter from spring-emerged $ , i.e., subbyemal conditions occurred 
with diminished sexual dimorphism. 
11. And going still further to day-flying moths (as a last instance 
given of these possibilities) one suspects, at any rate, one need not 
stop short of these without further observation. 
One is disposed to think that in Zyyaenids there is sexual dinior- 
phisim thus :— $> s on whole tend to larger spots of red on primaries, 
and to more red on secondaries owing to less encroachment of dark 
border, and $> s tend to bronzy-green or indigo green, and A s to 
indigo blue. Zyyaenids surely have bright protective colouring (dis¬ 
tasteful one believes in all stages except (?) pupa, they certainly stink 
as imagines), and ?s are thus most protected. (Jf melanism in 
Zyyaenids is result of subtestival conditions, it is quite evident that 
subfestival weather is associated with diminished sexual dimorphism 
by “diversion””). Certainly in no other year has one found it so 
easy to obtain bronze $ of Filipendidae or Irifolii, or broad border 
5 s, or narrow bordered A s of Filipendidae as in 1907 in one habitually- 
hunted locality. 
In connection with these observations it is noteworthy that if it 
turns out that melanisim in Zyyaenids is connected with subfestival con¬ 
ditions, and melanism in Aryynnids connected with superfestival con¬ 
ditions the conclusion is that the melanism is subordinate to other 
considerations ; it is an accident so to speak of other eventualities, 
and must have different causations, perhaps a score or more in different 
places. 
If one assumption further is granted, viz. : —increase of vigour 
makes for accentuation of characteristics—sexual included—in $ of 
virility and vice versa— viz., tends to perfect the individual— (e.y., in 
Adonis if brilliance and blueness are stamp of A , increase of vigour 
gives increase of brilliance and blueness; if this is so—if some 
blackening is mark of $ in Aylaia, and blackness is therefore more 
marked with greater vigour) this means that: Abnormal vigour of 
constitution in an individual is extremely likely to emphasize the 
characteristics natural to that individual (in virtue of sex, race, etc.), 
and vice versa. It certainly is so with human species. 
A brilliant colour may be that of a A , and this excess of vigour 
can increase them within any safe bounds through consecutive genera¬ 
tions, or the brilliant colour may be distinct protection of Zyyaenids 
* Melanie L. trifolii were as common in 1908 as in 1907. 
xviii. 
