e cocoon and the wall, which is
slightly worn owing to the circumstances described, they are able to
pass through the remaining occupied chambers and to reach the outside
first, whatever their original place in the stack of cells. It is just
possible that their early eclosion forces this method of exit upon them,
a method which, though often attempted, does not always succeed. The
females, furnished with stronger tools, make greater progress in my
tubes. I see some who pierce three or four partitions, one after the
other, and are so many stages ahead before those whom they have left
behind are even hatched. While they are engaged in this long and
toilsome operation, others, nearer to the orifice, have cleared a
passage whereof those from a distance will avail themselves. In this
way, it may happen that, when the width of the tube permits, an Osmia in
a back row will nevertheless be one of the first to emerge.

In the bramble-stem, which is of exactly the same diameter as
the cocoon, this escape by the side of the column appears hardly
practicable, except to a few males; and even these have to find a wall
which has so much pith that by removing it they can effect a passage.
Let us then imagine a tube so narrow as to prevent any exit save in the
natural sequence of the cells. What will happen? A very simple thing.
The newly-hatched Osmia, after perforating his partition, finds himself
faced with an unbroken cocoon that obstructs the road. He makes a few
attempts upon the sides and, realizing his impotence, retires into his
cell, where he waits for days and days, until his neighbour bursts her
cocoon in her turn. His patience is inexhaustible. However, it is not
put to an over long test, for within a week, more or less, the whole
string of females is hatched.

When two neighbouring Osmiae are released at the same time, mutual
visits are paid through the aperture between the two rooms: the one
above goes down to the floor below; the one below goes up to the floor
above; sometimes both of them are in the same cell together. Might not
this intercourse tend to cheer them and encourage them to patience?
Meanwhile, slowly, doors are opening here and there through the
separating walls; the road is cleared by sections; and a moment arrives
when the leader of the file walks out. The others follow, if ready; but
there are always laggards who keep the rear-ranks waiting until they are
gone.

To sum up, first, the hatching of the l