imilar kind, contrary to the
opinion of Buffon and Needham above recited.

Lastly, as all these filaments have possessed, or do possess, the power of
contraction, and of consequent inertion or elongation; it seems probable,
that the nutritive particles are applied during their times of elongation;
when their original constituent particles are removed to a greater distance
from each other. For each muscular or sensual fibre may be considered as a
row or string of beads; which approach, when in contraction, and recede
during its rest or elongation; and our daily experience shews us, that
great action emaciates the system, and that it is repaired during rest.

Something like this is seen out of the body; for if a hair, or a single
untwisted fibre of flax or silk, be soaked in water; it becomes longer and
thicker by the water, which is absorbed into its pores. Now if a hair could
be supposed to be thus immersed in a solution of particles similar to
those, which compose it; one may imagine, that it might be thus increased
in weight and magnitude; as the particles of oak-bark increase the
substance of the hides of beasts in the process of making leather. I
mention these not as philosophic analogies, but as similes to facilitate
our ideas, how an accretion of parts may be effected by animal appetences,
or selections, in a manner somewhat similar to mechanical or chemical
attractions.

If those new particles of matter, previously prepared by digestion and
sanguification, only supply the places of those, which have been abraded by
the actions of the system, it is properly termed nutrition. If they are
applied to the extremities of the nervous fibrils, or in such quantity as
to increase the length or crassitude of them, the body becomes at the same
time enlarged, and its growth is increased, as well as its deficiences
repaired.

In this last case something more than a simple apposition or selection of
particles seems to be necessary; as many parts of the system during its
growth are caused to recede from those, with which they were before in
contact; as the ends of the bones, or cartilages, recede from each other,
as their growth advances: this process resembles inflammation, as appears
in ophthalmy, or in the production of new flesh in ulcers, where old
vessels are enlarged, and new ones produced; and like that is attended with
sensation. In this situation the vessels become distended with blood, and
acquire greater sensibili