y
developed stage known as "fliers." To reach the "flying" or "migratory"
stage they pass through six different states, changing the colour of
their skin several times, gradually approaching to full growth, and
finally growing wings.

They have no quiescent stage, and whilst they are naturally yet
incapable of flight, their locomotive powers are very considerable, and
they are very destructive, for their voracity is great. Comparatively
speaking, the flying locusts do less damage to the growing crops than
the hoppers, who devour everything clean before them.

It is interesting to state that the "hoppers" in the first stage are in
length about 7 to 9 mm., or not quite one-third of an inch, and that the
feelers have thirteen divisions, extending to twenty-seven divisions at
full growth.

During the cold weather they usually gather together in thousands,
clinging closely to all kinds of vegetation and to each other. In this
season the general rule seems to be that comparatively little food is
taken of any kind. For the purpose of watching the development of their
eggs, several hundred locusts have been opened during the winter months
by entomologists, and invariably their cases have been found empty.

Perhaps the most feasible suggestion as to the cause of their migratory
impulse is that locusts naturally breed in dry sandy districts in which
food is scarce, and are thus impelled to wander in order to procure the
necessaries of life.

The rate of travel varies according to circumstances. With an
unfavourable wind, or little wind, they seldom travel more than five
miles an hour. At other times, when the wind is favourable, they will
cover fifteen to twenty miles per hour. When on the wing it is certain
that a distance of 1,000 miles may, in particular cases, be taken as a
moderate estimate of flight, and whilst, probably, it is often much
less, it is sometimes much more. Their height of flight has been
variously estimated at from forty to two hundred feet. "A dropping from
the clouds" is a common expression used by observers when describing the
apparition of a swarm.

It will not be denied that the presence of locusts in force constitutes
a terrible plague. They make their appearance in swarms and eat up
everything. It is wellnigh impossible to estimate the number in a cloud
of locusts, but some idea may be formed from the fact that when they are
driven, as sometimes is the case in a storm, into the sea and drowned,