afterwards advanced to the more powerful sex. For proof of this, the
economy of bees is cited; when they wish to raise a queen-bee, or true
female, they prepare for the larva a more commodious cell, and feed it
with delicate food. But we shall here stop to remark on the author's
argument up to this point.

It is manifest, according to his hypothesis, that neither sex nor
species depend on the ancestral germ, but simply on physical conditions
and mechanical development. But eminent physiologists deny that the
facts are such as he has stated; they deny, as we have stated in a
former section, that the foetal progress is such as the _Vestiges_
represent them to be; they deny that the human embryo, for example,
exhibits in successive stages the form of fish, lizard, bird, beast: on
the contrary, they contend that it is only in the earliest period of the
organic germ, when the manifestations are almost too obscure for
microscopic sense, that any resemblance exists; that immediately the
organic germ becomes sensible to observation, sex and species are found
to be fixed. Take, for example, the vertebrata; in these, by some
mysterious bond of union, the organic globules are seen to arrange
themselves into two nearly parallel rows. We may then say that the keel
of the animal is laid down, and in it we have the first rudiments of a
backbone and a continuous spinal chord. But during the progress and
completion of this first organic process no changes have been observed
assimilating the nascent embryo to any of the inferior animals. The next
series of changes in the germinal membrane are of two kinds--in one the
nervous system, the organs of motion, the intestinal canal, the heart
and blood-vessels are manifested; the other set of changes, which are
subsequent, produce the perfection of the animal and determine its sex.
All these manifestations result from germinal appendages that cannot be
severed or changed without ruin to the embryo, and the conditions