lichen reproduces the
green or brown incrustation which gave it birth; and at the other end of
the scale of life, the child that resembled neither the paternal nor the
maternal side of the house would be regarded as a kind of monster.

So that the one end to which, in all living beings, the formative
impulse is tending--the one scheme which the Archaeus of the old
speculators strives to carry out, seems to be to mould the offspring
into the likeness of the parent. It is the first great law of
reproduction, that the offspring tends to resemble its parent or
parents, more closely than anything else.

Science will some day show us how this law is a necessary consequence
of the more general laws which govern matter; but, for the present, more
can hardly be said than that it appears to be in harmony with them. We
know that the phenomena of vitality are not something apart from other
physical phenomena, but one with them; and matter and force are the two
names of the one artist who fashions the living as well as the
lifeless. Hence living bodies should obey the same great laws as other
matter--nor, throughout Nature, is there a law of wider application than
this, that a body impelled by two forces takes the direction of their
resultant. But living bodies may be regarded as nothing but extremely
complex bundles of forces held in a mass of matter, as the complex
forces of a magnet are held in the steel by its coercive force; and,
since the differences of sex are comparatively slight, or, in other
words, the sum of the forces in each has a very similar tendency, their
resultant, the offspring, may reasonably be expected to deviate but
little from a course parallel to either, or to both.

Represent the reason of the law to ourselves by what physical metaphor
or analogy we will, however, the great matter is to apprehend its
existence and the importance of the consequences deducible from it. For
things which are like to the same are like to one another; and if; in
a great series of generations, every offspring is like its parent, it
follows that all the offspring and all the parents must be like
one another; and that, given an original parental stock, with the
opportunity of undisturbed multiplication, the law in question
necessitates the production, in course of time, of an indefinitely large
group, the whole of whose members are at once very similar and are blood
relations, having descended from the same parent, or pair of par