But it must not be supposed that an animal or plant has ever conceived
the idea of some organ widely different from any it was yet possessed of,
and has set itself to design it in detail and grow towards it.
The small jelly-speck, which we call the amoeba, has no organs save what
it can extemporise as occasion arises. If it wants to get at anything,
it thrusts out part of its jelly, which thus serves it as an arm or hand:
when the arm has served its purpose, it is absorbed into the rest of the
jelly, and has now to do the duty of a stomach by helping to wrap up what
it has just purveyed. The small round jelly-speck spreads itself out and
envelops its food, so that the whole creature is now a stomach, and
nothing but a stomach. Having digested its food, it again becomes a
jelly-speck, and is again ready to turn part of itself into hand or foot
as its next convenience may dictate. It is not to be believed that such
a creature as this, which is probably just sensitive to light and nothing
more, should be able to form any conception of an eye and set itself to
work to grow one, any more than it is believable that he who first
observed the magnifying power of a dew-drop, or even he who first
constructed a rude lens, should have had any idea in his mind of Lord
Rosse's telescope with all its parts and appliances.
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