reat numbers.
The essential organs of generation, the testicles in the male and the
ovaries in the female, perform the task of collecting these gemmules
and forming them into sets, each of which constitutes a reproductive
element, and contains, in rudimentary form, a representative of every
part of the individual, including the most minute peculiarities. Even
more than this: It is supposed that each ovum and each zoosperm contains
not only the gemmules necessary to reproduce the individuals who
produced them, but also a number of gemmules which have been transmitted
from the individuals' ancestors.

If this theory be true,--and we can see no sound objection to it,--it
is easy to understand all the problems of heredity. The gemmules must
be very small indeed, but it may be suggested that the molecules of
matter are smaller still, so this fact is no objection to the theory.

It will be seen, then, that each spermatozoon, or zoosperm, actually
contains, in an embryonic condition, every organ and tissue of the
individual producing it. The same is true of the ovum. In other words,
the reproductive elements are complete representatives, in miniature,
of the parents, and contain all the elements for producing an offspring
possessing the same peculiarities as the parents. Various modifying
circumstances sufficiently explain the dissimilarities between
parents and children.

This theory is strikingly confirmed by the fact, previously mentioned,
that in certain cases the ovum alone, a single reproductive element,
may undergo a degree of development approaching very near to completion.
It is supposed that fecundation is chiefly necessary to give to the
gemmules the requisite amount of nourishment to insure development.

As we shall see hereafter, this matter has a very important bearing
upon several practical questions.

Ante-Natal Influences.--There can be no manner of doubt that many
circumstances which it is entirely within the power of the parents to
supply, exert a powerful influence in molding both the mental and the
physical characteristics of offspring. By carefully availing himself
of the controlling power given him by a knowledge of this fact, the
stock-raiser is enabled to produce almost any required quality in his
young animals. Pigeon fanciers show wonderful skill in thus producing
most curious modifications in birds. The laws of heredity and
development are carefully studied and applied in the production of
sup