elongs to the male, that of nourishing and cherishing is possessed by
the female; and these conditions are sexual distinctions. The former
represents _will_ and _understanding_; the latter, _vitality_ and
_emotion_. The father directs and controls, the mother fosters and
encourages; the former counsels and admonishes, the latter persuades and
caresses; and their union in holy matrimony represents one; that is, the
blending of vitality and energy, of love and wisdom,--the elements
indispensable to the initiation of life under the dual conditions of
male and female,--_one in the functions of reproduction_.

Let us consider the modes of Sexual Reproduction, which are
_hermaphroditic_ and _dioecious_.

HERMAPHRODITIC REPRODUCTION.

We have said that two kinds of cells represent reproduction, namely,
sperm and germ-cells. These may be furnished by different individuals,
or both may be found in one. When both are found in the same individual,
the parent is said to be a _natural hermaphrodite_. A perfect
hermaphrodite possesses the attributes of both male and female--uniting
both sexes in one individual. Natural hermaphroditic reproduction occurs
only among inferior classes of animals, and naturalists inform us that
there are a greater number of these than of the more perfect varieties.
These are found low in the scale of animal organization, and one
individual is able to propagate the species. In the oyster and ascidians
no organs can be detected in the male, but in the female they are
developed. Polyps, sponges, and cystic entozoa, may also be included
among hermaphrodites.

It is only very low organisms indeed in which it is a matter of
indifference whether the united sperm-cells and germ-cells are those of
the same individual, or those of different individuals. In more
elaborate structures and highly organized beings, the essential thing in
fertilization is the union of these cells specially endowed by
_different_ bodies, the unlikeness of derivation in these united
reproductive centers being the desideratum for perpetuating life and
power.

In other classes, as _entozoa_, there appear to be special provisions
whereby the sperm-cells and germ-cells may be united; _i.e._, the male
organs are developed and so disposed as to fecundate the ova of the same
individual. Sexual and non-sexual modes of reproduction are illustrated
by that well-defined group of marine invertebrate animals, called
_cirripedia_ Fig. 98 repre