How many people crack an egg, swallow the meat, and give it no further thought. Yet, to a reflective mind the egg constitutes, it has been said, the greatest wonder of nature. The highest problems of organic development, and even of the succession of animals on the earth, are embraced here. “Every animal springs from an egg,” is a dictum of Harvey that has become an axiom.

In an egg one would suppose the yolk to be the animal. This is not so. It is merely food—the animal is the little whitish circle seen on the membrane enveloping the yolk.

We hope to group a number of eggs, to enable our readers to compare their size and shape, from that of the Epyornis, six times the size of an Ostrich egg, down to the tiny egg that is found in the soft nest of the Humming-bird. This gigantic egg is a foot long and nine inches across, and would hold as much as fifty thousand Humming-bird’s eggs.