ther than community of descent.

"Mr. Darwin justly holds it to be incredible that individuals identically
the same should have been produced through Natural Selection from parents
_specifically distinct_, but he will not deny that identical forms may
issue from parents _genetically distinct_, when these parent forms and {95}
the conditions of production are identical. To deny this would be to deny
the law of causation."

Professor Huxley has, however, suggested[75] that such mineral identity may
be explained by applying also to minerals a law of descent; that is, by
considering such similar forms as the descendants of atoms which inhabited
one special part of the primitive nebular cosmos, each considerable space
of which may be supposed to have been under the influence of somewhat
different conditions.

Surely, however, there can be no real parity between the relationship of
existing minerals to nebular atoms, and the relationship of existing
animals and plants to the earliest organisms. In the first place, the
latter have produced others by generative multiplication, which mineral
atoms never did. In the second, existing animals and plants spring from the
living tissues of preceding animals and plants, while existing minerals
spring from the chemical affinity of separate elements. Carbonate of soda
is not formed, by a process of reproduction, from other carbonate of soda,
but directly by the suitable juxtaposition of carbon, oxygen, and sodium.

Instead of approximating animals and minerals in the mode suggested, it may
be that they are to be approximated in quite a contrary fashion; namely, by
attributing to mineral species an internal innate power. For, as we must
attribute to each elementary atom an innate power and tendency to form
(under the requisite external conditions) certain unions with other atoms,
so we may attribute to certain mineral species--as crystals--an innate
power and tendency to exhibit (the proper conditions being supplied) a
definite and symmetrical external form. The distinction between animals and
vegetables on the one hand, and minerals on the other, is that, while in
the organic world close similarity is the result sometimes of inheritance,
sometimes of direct production independently of parental action, in the{96}
inorganic world the latter is the constant and only mode in which such
similarity is produced.

When we come to consider the relations of species to space--in other words,
th