DEVELOPEMENT. 
63 
various germs from which the living creature is evolved ; 
for the small egg (rendered visible only when magnified a 
thousand times) of the microscopic Infusoria is quite as 
wonderful as the egg of the Ostrich, which is almost as 
large as a man’s head; and this, in turn, is not a whit 
more wonderful than the tiny globule enclosed within the 
secret sanctuary of the mother, from which springs “ man 
in God’s image.” The seed of the plant and the egg are 
one and the same thing, as regards the therein-contained 
marvel of life, which we see and grasp, though we are not 
in a position to understand it. As for the rest, all organic 
germs resemble one another, for they are all more or less 
similar in form. 
The germs which at present occupy our especial atten¬ 
tion appear, it is true, to differ much in size, form and 
colour, but are in the main, however, alike. The size of 
a bird’s egg is generally proportionate to the circum¬ 
ference of the body of the mother, and weighs about 
one-tenth of her own weight. Lammergeirs, Eagles 
and Cuckoos lay very small eggs; those of the Petrels, 
Auks and Guillemots are very large.* It is only in isolated 
cases that eggs differ much in shape from the common 
Hen’s egg, and then only in being either more spherical 
or approaching more the form of a pear. With regard to 
the colouring there is, on the whole, little to say. The 
eggs of birds breeding in holes are generally white ; those 
of birds breeding on the ground, earth- or grass-coloured ; 
birds building in trees, spotted; while those of bright- 
plumaged birds are often shiny white. 
It is immaterial at the present moment which bird’s 
egg we should select for cursory examination, with the 
* We suppose Dr. Brehm gives these examples as exceptions to the general 
rule.— W. J . 
