question.

PHYLOGENY OF SEXUAL LIFE

In Chapter II we have briefly described phylogeny in general or
metamorphosis, and in the first part of Chapter IV we have specially
considered the phylogeny of the sexual appetite in the phenomenon of
cell division and conjugation of nuclei in unicellular organisms,
which we have described in Chapter I. In order for animals to
reproduce themselves without degenerating, crossing, or the
combination of different germs, is necessary, and such combinations
are only possible by the mutual attraction of two kinds of germinal
cells. But, when the individual becomes multicellular and bears only
one kind of germinal cells, the attractive energy which was originally
limited to these cells is transmitted to the whole organism, and this
necessitates the existence of sensory and motor nerve centers.

The attraction of one kind of germinal cell and its bearer for the
other must also be more or less mutual. As a rule the bearer of one of
the germinal cells becomes active and penetrating; that of the other
passive and receptive. However, the latter, who after copulation (when
this occurs) becomes the sole bearer of the future individual, is
obliged to desire union with the active bearer of the other germinal
cell, so that reproduction may become harmonious. This is the basis on
which is founded sexual reproduction, and with it the sexual appetite,
in plants (as regards cellular conjugation only) as well as in
animals, but especially in the latter, in whom the germinal cells are
carried by mobile and independent individuals. On the same basis is
developed the difference between the sexual appetite in man and woman,
as well as that between love and the other irradiations of this
appetite in the mental life of both sexes. (Vide Chapters IV and V.)

The immense complication of human sexual life makes us regard animals
with a certain degree of contempt, and flatter our vanity in
qualifying the baser part of our sexual appetite by the term _animal
instinct_. But we are really very unjust toward animals. This
injustice is partly due to the fact that vocal and written language
gives us a means of penetrating into the psychology of our fellow
creatures. By the aid of the common symbolism of our thoughts it is
easy for us to compare them. Language thus enables us to construct a
general human psychology. The absence of language, even in the higher
animals, renders it difficult for us to penetrate their