iculate" influence over the reproductive elements
within him than a mother over the embryo or a vessel over its cargo.
Parent and offspring are like successive copies of books printed from
the same "type." A battered letter in the "type" will display its
effects in both earlier and later copies alike, but a purely extraneous
or acquired flaw in the first copy is not necessarily repeated in
subsequent copies. Unlike printer's type, however, the material source
of heredity is of a fluctuating nature, consisting of competing elements
derived from two parents and from innumerable ancestors.

Galton compares parent and child to successive pendants on the same
chain. Weismann likens them to successive offshoots thrown up by a long
underground root or sucker. Such comparisons indicate the improbability
of acquired modifications being transmitted to offspring.

That parts are developed in offspring independently of those parts in
parents is clear. Mutilated parents transmit parts which they do not
possess. The offspring of young parents cannot inherit the later stages
of life from parents who have not passed through them. Cases of remote
reversion or atavism show that ancestral peculiarities can transmit
themselves in a latent or undeveloped condition for hundreds or
thousands of generations. Many obvious facts compelled Darwin to suppose
that vast numbers of the reproductive gemmules in an individual are not
thrown off by his own cells, but are the self-multiplying progeny of
ancestral gemmules. Galton restricts the production of gemmules by the
personal structure to a few exceptional cases, and would evidently like
to dispense with pangenesis altogether, if he could only be sure that
acquired characters are never inherited. Weismann entirely rejects
pangenesis and the inheritance of acquired characters. This enables him
to explain heredity by his theory of the "Continuity of the
Germ-plasm."[67] Parent and offspring are alike successive products or
offshoots of this persistent germ-substance, which obviously would not
be correspondingly affected by modifications of parts in parents, and so
would render the transmission of acquired characters impossible.

INVERSE INHERITANCE.

Mr. Galton contends that the reproductive elements become sterile when
used in forming and maintaining the individual, and that only a small
proportion of them are so used.[68] He holds that the next generation
will be formed entirely, or almost ent