numbers, and small heath butterflies almost as many. The former, each and
every one of them, arrange themselves to look like part of the seed-spike
that caps the grass-stem. Then the use and purpose of the parti-coloured
grey and yellow under-colouring of their wings is seen. The butterfly
invariably goes to sleep head downwards, its eyes looking straight down
the stem of the grass. It folds and contracts its wings to the utmost,
partly, perhaps, to wrap its body from the cold. But the effect is to
reduce its size and shape to a narrow ridge, making an acute angle with
the grass-stem, hardly distinguishable in shape and colour from the
seed-heads on thousands of other stems around.[1] The butterfly also
sleeps on the top of the stem, which increases its likeness to the natural
finial of the grass. In the morning, when the sunbeams warm them, all
these grey-pied sleepers on the grass-tops open their wings, and the
colourless bennets are starred with a thousand living flowers of purest
azure. Side by side with the "blues" sleep the common "small heaths." They
use the grass-stems for beds, but less carefully, and with no such obvious
solicitude to compose their limbs in harmony with the lines of the plant.
They also sleep with their heads downwards, but the body is allowed to
droop sideways from the stem like a leaf. This, with their light
colouring, makes them far more conspicuous than the blues. Moreover, as
grass has no leaves shaped in any way like the sleeping butterfly, the
contrast of shape attracts notice. Can it be that the blues, whose
brilliant colouring by day makes them conspicuous to every enemy, have
learnt caution, while the brown heaths, less exposed to risk, are less
careful of concealment? Be it noticed that moths and butterflies go to
sleep in different attitudes. Moths fold their wings back upon their
bodies, covering the lower wing, which is usually bright in colour, with
the upper wing. They fold their antennas back on the line of their wings.
Butterflies raise the wings above their bodies and lay them back to back,
putting their antennae between them if they move them at all. On these