that nebulae (including comets), stars of all types, and
planets, are but varying stages in the life history of a
single race or type of cosmic organisms--is accepted
by the dominant thought of our time as having the
highest warrant of scientific probability.

All this, clearly, is but an amplification of that nebular
hypothesis which, long before the spectroscope gave
us warrant to accurately judge our sidereal neighbors,
had boldly imagined the development of stars out of
nebulae and of planets out of stars. But Lockyer's
hypothesis does not stop with this. Having traced the
developmental process from the nebular to the dark
star, it sees no cause to abandon this dark star to its
fate by assuming, as the original speculation assumed,
that this is a culminating and final stage of cosmic existence.
For the dark star, though its molecular activities
have come to relative stability and impotence,
still retains the enormous potentialities of molar motion;
and clearly, where motion is, stasis is not. Sooner
or later, in its ceaseless flight through space, the dark
star must collide with some other stellar body, as Dr.
Croll imagines of the dark bodies which his "pre-nebular
theory" postulates. Such collision may be long
delayed; the dark star may be drawn in comet-like circuit
about thousands of other stellar masses, and be
hurtled on thousands of diverse parabolic or elliptical
orbits, before it chances to collide--but that matters
not: "billions are the units in the arithmetic of eternity,"
and sooner or later, we can hardly doubt, a collision