result of the
operation of physical laws which must hold good in every instance of
nebular condensation.

Two different methods are presented in which a rotating and contracting
nebula may shape itself into a stellar or planetary system. The first is
that described by Laplace, and generally accepted as the probable manner
of origin of the solar system--viz., the separation of rings from the
condensing mass, and the subsequent transformation of the rings into
planets. The planet Saturn is frequently referred to as an instance of
the operation of this law, in which the evolution has been arrested
after the separation of the rings, the latter having retained the ring
form instead of breaking and collecting into globes, forming in this
case rings of meteorites, and reminding us of the comparatively
scattered rings of asteroids surrounding the sun between the orbits of
Mars and Jupiter. This Laplacean process Dr. See regards as
theoretically possible, but apparently he thinks that if it took place
it was confined to our system.

The other method is that of the separation of the original rotating mass
into two nearly equal parts. The mechanical possibility of such a
process has been proved, mathematically, by Poincare and Darwin. This,
Dr. See thinks, is the method which has prevailed among the stars, and
prevailed to such a degree as to make the solar system, formed by the
ring method, probably a unique phenomenon in the universe.

Is it not more probable that both methods have been in operation, and
that, in fact, the ring method has operated more frequently than the
other? If not, why do the single stars so enormously outnumber the
double ones? It is of the essence of the fission process that the
resulting masses should be comparable in size. If, then, that process
has prevailed in the stellar universe to the practical exclusion of the
other, there should be very few single stars; whereas, as a matter of
fact, the immense majority of the stars are single. And, remembering
that the sun viewed from stellar distances would appear unattended by
subsidiary bodies, are we not justified in concluding that its origin is
a type of the origin of the other single stars?

While it is, as I have remarked, of the essence of the fission process
that the resulting parts of the divided mass should be comparable in
magnitude, it is equally of the essence of the ring, or Laplacean
process, that the bodies separated from the original mass