ith the diffused gemmules of those cells which in the
perfect leg come next in order; and these as they become slightly developed
unite with others, and so on until a papilla of soft cellular tissue, the
"budding leg," is formed, and in time a perfect leg.[903] Thus, that
portion of the leg which had {377} been cut off, neither more nor less,
would be reproduced. If the tail or leg of a young animal had been cut off,
a young tail or leg would have been reproduced, as actually occurs with the
amputated tail of the tadpole; for gemmules of all the units which compose
the tail are diffused throughout the body at all ages. But during the adult
state the gemmules of the larval tail would remain dormant, for they would
not meet with pre-existing cells in a proper state of development with
which to unite. If from changed conditions or any other cause any part of
the body should become permanently modified, the gemmules, which are merely
minute portions of the contents of the cells forming the part, would
naturally reproduce the same modification. But gemmules previously derived
from the same part before it had undergone any change, would still be
diffused throughout the organisation, and would be transmitted from
generation to generation, so that under favourable circumstances they might
be redeveloped, and then the new modification would be for a time or for
ever lost. The aggregation of gemmules derived from every part of the body,
through their mutual affinity, would form buds, and their aggregation in
some special manner, apparently in small quantity, together probably with
the presence of gemmules of certain primordial cells, would constitute the
sexual elements. By means of these illustrations the hypothesis of
pangenesis has, I hope, been rendered intelligible.

* * * * *

Physiologists maintain, as we have seen, that each cell, though to a large
extent dependent on others, is likewise, to a certain extent, independent
or autonomous. I go one small step further, and assume that each cell casts
off a free gemmule, which is capable of reproducing a similar cell. There
is some analogy between this view and what we see in compound animals and
in the flower-buds on the same tree; for these are distinct individuals
capable of true or seminal reproduction, yet have parts in common and are
dependent on each other; thus {378} the tree has its bark and trunk, and
certain corals, as the Virgularia, ha