nd yet not respond at all to the conditions which we apply as tests of
the existence of life.

This is but another way of saying that the peculiar limitations of
specialized aggregations of matter which characterize what we term
living matter may be mere incidental details of the evolution of our
particular star group, our particular planet even--having some such
relative magnitude in the cosmic order, as, for example, the exact
detail of outline of some particular leaf of a tree bears to the
entire subject of vegetable life. But, on the other hand, it is also
conceivable that the conditions on all planets comparable in position to
ours, though never absolutely identical, yet pass at some stage
through so similar an epoch that on each and every one of them there is
developed something measurably comparable, in human terms, to what
we here know as living matter; differing widely, perhaps, from any
particular form of living being here, yet still conforming broadly to
a definition of living things. In that case the life-bearing stage of
a planet must be considered as having far more general significance;
perhaps even as constituting the time of fruitage of the cosmic
organism, though nothing but human egotism gives warrant to this
particular presumption.

Between these two opposing views every one is free to choose according
to his preconceptions, for as yet science is unable to give a deciding
vote. Equally open to discussion is that other question, as to whether
the evolution of universal atoms into a "vital" association mass from
which all the diversified forms evolved, or whether such shifting from
the so-called non-vital to the vital was many times repeated--perhaps
still goes on incessantly. It is quite true that the testimony of our
century, so far as it goes, is all against the idea of "spontaneous
generation" under existing conditions. It has been clearly enough
demonstrated that the bacteria and other low forms of familiar life
which formerly were supposed to originate "spontaneously" had a quite
different origin. But the solution of this special case leaves the
general problem still far from solved. Who knows what are the conditions
necessary to the evolution of the ever-present atoms into "vital"
associations? Perhaps extreme pressure may be one of these conditions;
and, for aught any man knows to the contrary, the "spontaneous
generation" of living protoplasms may be taking place incessantly at the
bottom of