to witness.

The first-hatched Osmia, wherever she may be, has made a hole in her
ceiling. She is now in the presence of the next cocoon, with her head
at the opening of the hole. In front of her sister's cradle, she usually
stops, consumed with shyness; she draws back into her cell, flounders
among the shreds of the cocoon and the wreckage of the ruined ceiling;
she waits a day, two days, three days, more if necessary. Should
impatience gain the upper hand, she tries to slip between the wall of
the tunnel and the cocoon that blocks the way. She even undertakes the
laborious work of gnawing at the wall, so as to widen the interval, if
possible. We find these attempts, in the shaft of a bramble, at places
where the pith is removed down to the very wood, where the wood itself
is gnawed to some depth. I need hardly say that, although these lateral
inroads are perceptible after the event, they escape the eye at the
moment when they are being made.

If we would witness them, we must slightly modify the glass apparatus.
I line the inside of the tube with a thick piece of whity-brown
packing-paper, but only over one half of the circumference; the other
half is left bare, so that I may watch the Osmia's attempts. Well,
the captive insect fiercely attacks this lining, which to its eyes
represents the pithy layer of its usual abode; it tears it away by tiny
particles and strives to cut itself a road between the cocoon and the
glass wall. The males, who are a little smaller, have a better chance of
success than the females. Flattening themselves, making themselves thin,
slightly spoiling the shape of the cocoon, which, however, thanks to
its elasticity, soon recovers its first condition, they slip through the
narrow passage and reach the next cell. The females, when in a hurry
to get out, do as much, if they find the tube at all amenable to the
process. But no sooner is the first partition passed than a second
presents itself. This is pierced in its turn. In the same way will the
third be pierced and others after that, if the insect can manage them,
as long as its strength holds out. Too weak for these repeated borings,
the males do not go far through my thick plugs. If they contrive to cut
through the first, it is as much as they can do; and, even so, they
are far from always succeeding. But, in the conditions presented by
the native stalk, they have only feeble tissues to overcome; and then,
slipping, as I have said, between th