The hen or incubator merely keeps it warm during the period of incubation. By the end of the twenty-first day, the contents of the egg-shell have been converted into a live bird, with a skeleton, muscles, arteries, veins, nerves, brain, eyes, ears, heart, lungs, liver, wings, legs, feet, etc. There is no skeleton, model, nor any other performed outline of the coming chick, in the egg; for the contents of the egg-shell are a homogeneous mass of protoplasm. There is no reason to suppose that the warmth of the hen’s body, nor that the heat of the incubator, is, alone, adequate to impart life to the egg. Each part of the egg is necessarily kept at the same temperature as that of every other part. For this reason we cannot believe that mere heat differentiates one part of the white and yellow into bones, another part into muscles, arteries, veins, nerves, etc.
In his Principles of Biology, (vol. 1, p. 116), Spencer says:
“There is experimental proof that seeds may, under conditions unfavorable to germination, retain for ten, twenty, and some even thirty years, the power to germinate when due moisture and warmth are supplied.”
Now if these seeds are alive, what becomes of the life in them during these long periods of quiescence? There are untold millions of grains of wheat and of corn. None of these grains will germinate until they are supplied with “moisture and warmth.” Can we believe that heat and moisture alone have any creative forces? If so, all the sands of the sea shore ought to be living creatures.
Let us consider the acorn. When mature, it falls to the ground. If it be supplied with a proper degree of heat and moisture, it will germinate in a short time. But it will never germinate, so long as it is kept in a cool, dry place. Suppose an acorn is deprived of heat and moisture for five years; that it is then supplied with them and immediately germinates. When did the life of the acorn begin? Did it begin when the acorn ripened and dropped to the ground or when it germinated? If it was alive when it first matured, and germinated five years afterward, what became of its life between its maturity and its germination? Is it not reasonable to suppose that the Creator endowed it with life when it germinated?