heir helpless children.

[Illustration: Fig. 1.--Peregrine Falcon, and young ones.]

[Illustration: Fig. 2.--Ringed Plover, and young ones.]

The unlikeness to the parents is most marked, as we have said, where the
young are cast upon the world to look after themselves, often as
microscopic creatures. The reason of this is because they have come from
eggs which were so tiny that they could not contain enough food to
support the growing body within until it had assumed its final shape. In
consequence, the little creature had to start life in some more simple
form, capable of feeding on the tiniest particles of food. This early
development is unavoidable in cases where a single family may number
some hundreds or thousands of individuals. But when only a few young
ones make up a family, you will notice they are more or less jealously
guarded by the parents, and they, furthermore, come into the world more
nearly in the shape they are finally to assume.

Many of you, I hope, when you grow up, will be tempted to try and follow
out these strange life-histories for yourselves. In this article I
propose to describe some of the more interesting forms of young to be
met with among the birds, because here, at any rate, you will be able to
follow up the facts at once; and a very fascinating pursuit you will
find it.

Birds, as every one knows, lay eggs, which, after a time, produce
chicks, some of which, like ducks and chickens, for example, can run
about and pick up food within an hour or two of their escape from the
shell; but for a long time they are most carefully tended by their fond
parents, who will brave many dangers in their defence. Now, the
difference between the young chicken, or the young duck, and their
parents is not very great, and this is because the egg from which they
came contained a large supply of food, so that all the building up of
the body could be carried on inside the shell. This food is represented
by the yolk of the egg, of which there was an enormous store. That this
is so you can see for yourselves, if you break an egg into a cup. The
little spot in the top of the yolk represents the germ of life that is
to form the chick; the rest of the yolk is to be used by that germ as
food.

[Illustration: Fig. 3 Skylark, and young ones.]

As you doubtless know, however, some young birds, like young rooks and
sparrows, thrushes and skylarks, when they leave the egg, are perfectly
bare, blind, and helpless,