The Bird in the Egg 463 
and the presence of water in the other, will slowly take 
on the semblance of living creatures; the one eventually 
to swim forth, live the life of a fish for a time, then to 
leap upon the land and croak among the reeds. The 
other yolk would have evolved into a downy, yellow chick. 
We cannot hope to solve the mystery of life, but there 
is a fascination in seeing how near its beginnings we can 
approach. 
Fic, 364.—Egg of Hen, opened to show a 3-day embryo in position on the yolk. 
(Slightly enlarged.) 
If we have ever watched under the microscope the strange 
little creatures which live in the mud at the bottom of 
ponds, we will have realized the wonderful possibilities of a 
single drop of living matter,—a single cell,—from the 
amoeba with its ever-changing shape to the swiftly moving 
slipper paramecium and the beautiful animal vases,—the 
