58 
I venture to assume, by any of these phenomena. Climate may alter 
the pigments of lepidoptera, the scale-structure, or the size of a speci¬ 
men by its injurious ( i.e ., abnormal) action on the larva or pupa ; 
but none of these alterations are hereditary. Food, according to its 
nutritious (or innutritious) value, will produce large or small speci¬ 
mens ; but size alone is not a specific character. It generates no new 
modification of an existent organ. Sexual selection is, in Lepidop¬ 
tera, I believe, practically an unknown quantity, and probably in 
some other families of organised beings, the supposed action in this 
direction is much overrated. I fail, entirely, to see how either 
isolation or the laws of growth can originate a new structure, or 
modify an existent one per se, although both forces are valuable for 
the development of a modification, once it has taken place. 
UTILITY OF SPECIFIC CHARACTERS. 
It must be evident to anyone who will logically consider the subject 
that, if the survival of the fittest be the one test by which species exist, 
and that all species have been brought about by a gradual and almost 
imperceptible transition from other species, the change which 
takes place and becomes fixed in the species— i.e., the specific 
•character—and which separates it from its immediate ancestor, must 
be a change that will be useful to the species, and that, therefore, the 
presence of useless specific characters, so-called, is more likely to be 
due to our failure to understand their use, rather than to any likeli¬ 
hood of their actual uselessness. In no case that occurs to me do any 
local races of Lepidoptera exist in certain areas to the exclusion of 
the type, except in the one case of Polyommatus astrarche var. 
artaxerxes, which is almost restricted to certain localities in Scotland, 
without our being able at once to show that they are adaptations to 
■environmental conditions, which make the differentiating features of 
the utmost use to the races exhibiting it, and as these various local races 
have assumed their racial characters for purely utilitarian purposes, or 
are the result of conditions under which the normal type would cease 
to exist, so we may rest assured the characters retained by various 
species have been those which have remained useful to the species. 
These characters which now distinguish them as species most 
probably originated as racial peculiarities, because they were of use, 
and enabled them to win in the struggle for existence which they 
were obliged to wage against the various species by which they were 
everywhere surrounded, and, so far as an intimate study of our 
Lepidopterous fauna allows me to judge, I should say that certainly 
every specific character is, or has been, correlated with a character 
useful to the species. 
PRESENT POSSIBILITIES OF INTELLECTUAL TRAINING AND CONVERSE. 
And now, I would urge all those of our members who have recently 
commenced the study of entomology, to work at our favourite subject, 
honestly and laboriously, during such leisure as they may be able to 
devote to it, that, having put their hand to the plough, they turn not 
back again. I often wonder whether each and every of our younger 
members have ever thought what a vast field has been opened up of 
recent years to those who are comparatively poor. Has he ever con¬ 
sidered, that until quite recently, intellectual meetings like those of 
our Society were possible only to men of wealth and leisure, that 
culture was then the freehold of the rich. Now the good things of 
