admitted that all the higher forms of life arise only by process of
natural generation from others of their own kind; but did not these
microscopic organisms prove that there was "a perpetual abiogenetic
fount by which the first steps in the evolution of living organisms
continued to arise, under suitable conditions, from inorganic
matter"?[9]

[Footnote 9: Encyclopædia Britannica, Vol. I, p. 64.]

The famous "barnacle-geese" ought not to be omitted from any sketch of
the vicissitudes of this doctrine of Biogenesis. An elaborate
illustrated account covering their alleged natural history was printed
in one of the early volumes of the Royal Society of London. Buds of a
particular tree growing near the sea were described as producing
barnacles, and these falling into the water were alleged to be
transmuted into geese. Nor should we omit mention of Huxley's _Bathybius
Haeckelii_, a slimy substance supposed to exist in great masses in the
depths of the ocean and to consist of undifferentiated protoplasm, the
exhaustless fountain from which all other forms of life had been
derived. Not long after Huxley had given it a formal scientific name in
1868, it was discovered to be merely a precipitate of gypsum thrown down
from sea water by alcohol, and thus a product of clumsy manipulation in
the laboratory, instead of a natural product of the deep sea. The
disappointment of those opposing biogenesis was severe; but the lesson
is still of value to the world to-day.

The masterly work of Tyndall and Louis Pasteur in doing for the bacteria
and protozoa what Redi had done for the larger organisms, is too much a
matter of modern contemporary history to need recital here. Upon this
great truth of life only from life is based all the recent advances in