One of the million has twice as good a chance as any other of surviving; but the chances are fifty to one against the gifted individuals being one of the hundred survivors.

No doubt the chances are twice as great against any one other individual, but this does not prevent their being enormously in favour of _some_ average individual.

However slight the advantage may be, if it is shared by half the individuals produced, it will probably be present in at least fifty-one of the survivors, and in a larger proportion of their offspring; but the chances are against the preservation of any one 'sport' (_i.e._ sudden, marked variation) in a numerous tribe.

The vague use of an imperfectly understood doctrine of chance has led Darwinian supporters, first, to confuse the two cases above distinguished; and, secondly, to imagine {58} that a very slight balance in favour of some individual sport must lead to its perpetuation.

All that can be said is that in the above example the favoured sport would be preserved once in fifty times.