cult of comprehension that the dog might once have
been a wolf. Though not quite so credible, it did not seem absurd that
the tigers, lions, and leopards should have once all been alike. The
resemblance between these are strong enough to make the idea seem
conceivable. Though men were willing to concede this much, they
insisted that the great branches of the animal kingdom varied so
widely from each other as to make it certain that each was a separate
creation. It was particularly objected that the mammals differed so
entirely from other animals in several important particulars that a
special divine act was necessary for their appearance. The mammals
have a furry covering entirely different from the clothing of any
other animal in the kingdom, and have warm blood, which is found
nowhere else except among the birds. But particularly their method of
producing their young seemed so entirely different from that of any
other group that here a special creation was deemed absolutely
necessary.

Other young creatures are produced from eggs laid by the parent and
subsequently hatched. The young of the mammals are born alive and
comparatively well developed. In addition, their first food, the milk
of the mother, is so entirely different from the food of any other
creature that this again seemed to involve a separate creation.
Gradually we have come to understand the whole matter of reproduction
very much better. Minute and careful dissections of rabbits, of dogs
and cats, of animals slaughtered for food, with occasional post-mortem
examinations of human beings in various stages of the development of
the young, leave us no longer in doubt concerning the main features of
the process. The better we come to understand it the more clearly it
becomes evident that in the development of the mammals we have no new
procedure, but, as in so many other activities, new developments of an
old process.

There are two entirely different methods by which new animals and
plants may arise. One sees sometimes in the home of a friend a
geranium of particular beauty, the like of which he would be glad to
possess. The accommodating friend cuts a small piece from the
geranium. This is stuck into poor but well-watered ground, develops
roots, and eventually grows into a geranium stalk exactly like the one
from which it came and of which it is in reality only a detached part.

In similar fashion, if one wants a particular kind of apple, he never
trusts