Supposing that all the Osmiae possessed the necessary strength of jaw
as well as the instinct for this sideward boring, it is clear that
egress from each cell through a special window would be much more
advantageous than egress through the common door. The Bee could
attend to his release as soon as he was hatched, instead of
postponing it until after the emancipation of those who come before
him; he would thus escape long waits, which too often prove fatal. In
point of fact, it is no uncommon thing to find bramble-stalks in
which several Osmiae have died in their cells, because the upper
storeys were not vacated in time. Yes, there would be a precious
advantage in that lateral opening, which would not leave each
occupant at the mercy of his environment: many die that would not
die. All the Osmiae, when compelled by circumstances, resort to this
supreme method; all have the instinct for lateral boring; but very
few are able to carry the work through. Only the favourites of fate
succeed, those more generously endowed with strength and
perseverance.

If the famous law of natural selection, which is said to govern and
transform the world, had any sure foundation; if really the fittest
removed the less fit from the scene; if the future were to the
strongest, to the most industrious, surely the race of Osmiae, which
has been perforating bramble-stumps for ages, should by this time
have allowed its weaker members, who go on obstinately using the
common outlet, to die out and should have replaced them, down to the
very last one, by the stalwart drillers of side-openings. There is an
opportunity here for immense progress; the insect is on the verge of
it and is unable to cross the narrow intervening line. Selection has
had ample time to make its choice; and yet, though there be a few