IV 
THE BABY BIRD 
A sapy bird, as you know, always comes out 
of an egg. And beautiful as these eggs are, 
they are most interesting when you think that 
each one holds a tiny bird. 
Eggs are not all alike, of course. One the 
size of a bean is large enough to hold a hum- 
mingbird baby, till it is old enough to come 
out. But the young ostrich needs a shell nearly 
as big as your head. So there are all sizes of 
egos to fit the different sizes of birds. 
If you should break a fresh egg you would 
not see a bird, for it would not be formed at 
that time. After the egg is laid in its soft bed, 
it has to be kept warm for many days, and that 
is why the mother bird sits on her nest so 
quietly. She is keeping the eggs warm, so that 
the little ones will form and grow, till they are 
as big as the shells can hold. 
While the mother is sitting her mate does all 
he can to help, though each species has its own 
