is inspection, perhaps the most worthy of
admiration is the development of a plant or of an animal from its
embryo. Examine the recently laid egg of some common animal, such as a
salamander or newt. It is a minute spheroid in which the best microscope
will reveal nothing but a structureless sac, enclosing a glairy fluid,
holding granules in suspension. But strange possibilities lie dormant
in that semi-fluid globule. Let a moderate supply of warmth reach its
watery cradle, and the plastic matter undergoes changes so rapid, yet
so steady and purposelike in their succession, that one can only compare
them to those operated by a skilled modeller upon a formless lump of
clay. As with an invisible trowel, the mass is divided and subdivided
into smaller and smaller portions, until it is reduced to an aggregation
of granules not too large to build withal the finest fabrics of the
nascent organism. And, then, it is as if a delicate finger traced out
the line to be occupied by the spinal column, and moulded the contour
of the body; pinching up the head at one end, the tail at the other,
and fashioning flank and limb into due salamandrine proportions, in so
artistic a way, that, after watching the process hour by hour, one is
almost involuntarily possessed by the notion, that some more subtle aid
to vision than an achromatic, would show the hidden artist, with his
plan before him, striving with skilful manipulation to perfect his work.

As life advances, and the young amphibian ranges the waters, the terror
of his insect contemporaries, not only are the nutritious particles
supplied by its prey, by the addition of which to its frame, growth
takes place, laid down, each in its proper spot, and in such due
proportion to the rest, as to reproduce the form, the colour, and the
size, characteristic of the parental stock; but even the wonderful
powers of reproducing lost parts possessed by these animals are
controlled by the same governing tendency. Cut off the legs, the tail,
the jaws, separately or all together, and, as Spallanzani showed long
ago, these parts not only grow again, but the reintegrated limb is
formed on the same type as those which were lost. The new jaw, or leg,
is a newt's, and never by any accident more like that of a frog. What is
true of the newt is true of every animal and of every plant; the acorn
tends to build itself up again into a woodland giant such as that from
whose twig it fell; the spore of the humblest