428 The Bird 
chance in the lottery of life in the open ocean. Of her 
nine millions of eggs, will one survive? 
How strange is the four-tendriled, purse-like cradle 
of the baby shark; how delicate the forms and patterns 
of butterflies’ eggs! and was there ever a more model 
parent than that frog which holds its eggs in its mouth 
until the tadpoles grow up? 
The white leathery eggs of turtles and lizards bring 
us to our subject. Leading all in beauty and interest are 
the eggs of birds. Precious stones have always exerted 
a great fascination over mankind, and in appearance 
birds’ eggs may be compared with gems; indeed the shell 
itself is almost wholly composed of mineral matter. But, 
far from being an inanimate crystal, an egg shelters one 
of the marvels of the world—an embryo bird. The 
gaudy sea-shell cloaks a slimy snail, but from the beautiful 
egg of a bird emerges a greater beauty. 
Reptiles lay white eggs whose shells are not brittle, 
but, when broken, curl up like a celluloid film. Some 
of these reptilian eggs are oblong in shape, but most are 
spherical and the great majority are deposited in the 
ground, or under bark, and are hatched by the heat of the 
decaying vegetation or by the direct rays of the sun. 
Thus we see that there is little need for variation in 
shape or colour. Among birds, however, we find very 
different conditions. 
As we know that birds have evolved from reptiles, 
we have a right to suppose that the early forms of birds 
laid white, leathery eggs, perhaps in hollow trees; but 
the power of flight has taken birds entirely out of the 
