INSTINCT AND HABIT. 
7 
life history, and the one aspect is as important as the other. Our know¬ 
ledge of structure is far greater than our familiarity with the habits of 
insects, but the latter will increase. It is all important for the student 
to grasp clearly from the beginning that a “ species” is a distinct indivi¬ 
dual as much in habits, mode of life and all details of its life as in its 
colour, form, or any structural detail on which it is declared to be a 
distinct species. We are here far more concerned with the living insect 
as a living reality than with the dead shell on which its place in the 
insect world is determined and on which it is described and named; the 
characters of the living insect, its method of flight, its walk, its feeding 
habits, its expressive antennal movements, all the details of its daily 
life are of as great value as its structure and are of far greater importance 
to us in these pages ; a realisation of this fact and an understanding of 
what a species really is, must come to every student sooner or later if he 
is to become anything more than a systematist and a classifier of insects 
on purely structural details; the individuality of a species is as much 
discernable in the field as in the museum and takes in every detail of 
the insects life. For that reason, we have considered this abstruse point 
at some length and we would emphasize the point of view given, though 
it may seem at first sight an incorrect one. Variations in habits between 
two members of a species are so small that what we find out of a single 
individual, applies to every individual of that species with due allow¬ 
ance for variable conditions ; a very large part of our work lies in deter¬ 
mining how far different conditions modify the habits of an insect and 
the limits of this variation are becoming clearly established; if, therefore, 
the habits of an insect are observed in Peshawar, we know that the 
individuals of that species will have in the main the same habits at 
Madras, that we can predict the variations likely to be found, and that 
if we knew enough we could absolutely say how far they would differ. 
We may touch very lightly upon one more point; whence come the 
instincts and beautiful habits of our present-day insects ? According 
to the accepted theories of evolution, insects, like other animals, are 
descended from more primitive forms of life which existed in earlier 
geologic periods; if we imagine the primitive types of insects being 
evolved and multiplying, and supposing them to feed on the abundant 
decaying vegetable matter, we shall get a great development of simpler 
forms scattered over large areas of land, and living in a diversity of physi- 
