which we would otherwise receive from the more distant bodies of
the universe? It is, of course, impossible to answer this question
in a positive way, but the probable conclusion is a negative one.
We may say with certainty that dark stars are not so numerous as
to cut off any important part of the light from the stars of the
Milky Way, because, if they did, the latter would not be so
clearly seen as it is. Since we have reason to believe that the
Milky Way comprises the more distant stars of our system, we may
feel fairly confident that not much light can be cut off by dark
bodies from the most distant region to which our telescopes can
penetrate. Up to this distance we see the stars just as they are.
Even within the limit of the universe as we understand it, it is
likely that more than one-half the stars which actually exist are
too faint to be seen by human vision, even when armed with the
most powerful telescopes. But their invisibility is due only to
their distance and the faintness of their intrinsic light, and not
to any obstructing agency.

The possibility of dark stars, therefore, does not invalidate the
general conclusions at which our survey of the subject points. The
universe, so far as we can see it, is a bounded whole. It is
surrounded by an immense girdle of stars, which, to our vision,
appears as the Milky Way. While we cannot set exact limits to its
distance, we may yet confidently say that it is bounded. It has
uniformities running through its vast extent. Could we fly out to
distances equal to that of the Milky Way, we should find
comparatively few stars beyond the limits of that girdle. It is
true that we cannot set any definite limit and say that beyond
this nothing exists. What we can say is that the region containing
the visible stars has some approximation to a boundary. We may