Something similar to this process of budding, we find taking place in a low order of animal organization. Divide the fresh water polyp into several pieces, and each one will grow into an entire animal. Each piece represents a polyp, and so each parent polyp is really a compound animal, an organized community of beings. Just as the buds of a tree, when separated and engrafted upon another tree, grow again, each preserving its original identity, so do the several parts of this animal, when divided, become individual polyps, capable of similar reproduction. [Illustration: Fig. 97. An annelid dividing spontaneously, a new head having been formed toward the hinder part of the body of the parent.] The revolving volvox likewise increases by growth until it becomes a society of animals, a multiple system of individuals. There are apertures from the parent, by which water gains a free access to the interior of the whole miniature series. This monad was once supposed to be a single animal, but the microscope shows it to be a group of animals connected by means of six processes, and each little growing volvox exhibits his red-eye speck and two long spines, or horns. These animals also multiply by dividing, and thus liberate another series, which, in their turn, reproduce other groups. Generation requires the concurrence of _stimuli_ and _susceptibility_, and, to perfect the process, two conditions are also necessary. The first is the sperm, which communicates the principle of action; the other is the germ, which receives the latent life and provides the conditions necessary to organic evolution. The vivifying function belongs 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.