gs. How the wings arose, what function their precursors
performed before they became capable of supporting flight, we can hardly
even guess.

Our study of the life-story of insects, therefore, while it has taught
us something of what is going on around us to-day, and has given us
hints of the course of a few threads of that long life-story which runs
through the ages, brings us face to face with the most instructive, if
humbling fact that 'there are many more things of which we are
ignorant.' The passage from creeping to flight, as the caterpillar
becomes transformed into the butterfly, was a mystery to those who first
observed it, and many of its aspects remain mysterious still. Perhaps
the most striking result of the study of insect transformation is the
appreciation of the divergent specialisation of larva and imago, and it
is a suggestive thought that of the two the larva has in many cases
diverged the more from the typical condition. The caterpillar crawling
over the leaf, or the fly-grub swimming through the water, may thus be
regarded as a creature preparing for a change to the true conditions of
its life. It is a strange irony that the preparation is often far longer
than the brief hours of achievement. But the light which research has
thrown on the nature of these wonderful life-stories, the demonstration
of the unseen presence and growth within the insect, during its time of
preparation among strange surroundings, of the organs required for
service in the coming life amid its native air, confirm surely the
intuition of the old-time students, who saw in these changes, so
familiar and yet so wonderful, a parable and a prophecy of the higher
nature of man.

OUTLINE CLASSIFICATION OF INSECTS

Class INSECTA or HEXAPODA.

Sub-class A, APTERYGOTA.

Order 1. _Thysanura_ (Bristle-tails).
2. _Collembola_ (Spring-tails).

Sub-class B, EXOPTERYGOTA.

Order 1. _Dermaptera_ (Earwigs).
2. _Orthoptera_ (Cockroaches, Grasshoppers, Crickets).
3. _Plecoptera_ (Stone-flies).
4. _Isoptera_ (Termites or 'White Ants').
5. _Corrodentia_
(_a_) _Copeognatha_ (Book-lice).
(_b_) _Mallophaga_ (Biting-lice).
6. _Ephemeroptera_ (May-flies).
7. _Odonata_ (Dragon-flies).
8. _Thysanoptera_ (Thrips).
9. _Hemiptera_
(_a_) _Heteroptera_ (Bugs, Pond-skaters)
(_b_) _Homoptera_ (Cicads, 'Greenfly,' Scales).
10. _Anoplura_ (Lice).