of becoming that which their parents were. Thus the butterfly lays an
egg, which egg can become a caterpillar, which caterpillar can become a
chrysalis, which chrysalis can become a butterfly; and though I freely
grant that the machines cannot be said to have more than the germ of a
true reproductive system at present, have we not just seen that they have
only recently obtained the germs of a mouth and stomach? And may not
some stride be made in the direction of true reproduction which shall be
as great as that which has been recently taken in the direction of true
feeding?

"It is possible that the system when developed may be in many cases a
vicarious thing. Certain classes of machines may be alone fertile, while
the rest discharge other functions in the mechanical system, just as the
great majority of ants and bees have nothing to do with the continuation
of their species, but get food and store it, without thought of breeding.
One cannot expect the parallel to be complete or nearly so; certainly not
now, and probably never; but is there not enough analogy existing at the
present moment, to make us feel seriously uneasy about the future, and to
render it our duty to check the evil while we can still do so? Machines
can within certain limits beget machines of any class, no matter how
different to themselves. Every class of machines will probably have its
special mechanical breeders, and all the higher ones will owe their
existence to a large number of parents and not to two only.

"We are misled by considering any complicated machine as a single thing;
in truth it is a city or society, each member of which was bred truly
after its kind. We see a machine as a whole, we call it by a name and
individualise it; we look at our own limbs, and know that the combination
forms an individual which springs from a single centre of reproductive
action; we therefore assume that there can be no reproductive action
which does not arise from a single centre; but this assumption is
unscientific, and the bare fact that no vapour-engine was ever made
entirely by another, or two others, of its own kind, is not sufficient to
warrant us in saying that vapour-engines have no reproductive system. The
truth is that each part of every vapour-engine is bred by its own special
breeders, whose function it is to breed that part, and that only, while
the combination of the parts into a whole forms another department of the
mechanical reprod