Bramble-Bees and Others | Page 6

second cell.
As for the rubbish, it is utilized on the spot for the lid or cover that
serves as a ceiling for one cell and a floor for the next. Our own
master-builders could not contrive more successfully to make the best
use of their labourers' time. On the floor thus obtained, a second ration
of honey is placed; and an egg is laid on the surface of the paste. Lastly,
at the upper end of the little barrel, a partition is built with the scrapings
obtained in the course of the final work on the third cell, which itself is
shaped like a flattened ovoid. And so the work goes on, cell upon cell,
each supplying the materials for the partition separating it from the one
below. On reaching the end of the cylinder, the Osmia closes up the
case with a thick layer of the same mortar. Then that bramble-stump is
done with; the Bee will not return to it. If her ovaries are not yet
exhausted, other dry stems will be exploited in the same fashion.
The number of cells varies greatly, according to the qualities of the
stalk. If the bramble-stump be long, regular and smooth, we may count
as many as fifteen: that, at least, is the highest figure which my
observations have supplied. To obtain a good idea of the internal

distribution, we must split the stalk lengthwise, in the winter, when the
provisions have long been consumed and when the larvae are wrapped
in their cocoons. We then see that, at regular intervals, the case
becomes slightly narrower; and in each of the necks thus formed a
circular disk is fixed, a partition one or two millimetres thick. (.039
to .079 inch.--Translator's Note.) The rooms separated by these
partitions form so many little barrels or kegs, each compactly filled
with a reddish, transparent cocoon, through which the larva shows, bent
into a fish-hook. The whole suggests a string of rough, oval amber
beads, touching at their amputated ends.
In this string of cocoons, which is the oldest, which the youngest? The
oldest is obviously the bottom one, the one whose cell was the first
built; the youngest is the one at the top of the row, the one in the cell
last built. The oldest of the larvae starts the pile, down at the bottom of
the gallery; the latest arrival ends it at the top; and those in between
follow upon one another, according to age, from base to apex.
Let us next observe that there is no room in the shaft for two Osmiae at
a time on the same level, for each cocoon fills up the storey, the keg
that belongs to it, without leaving any vacant space; let us also remark
that, when they attain the stage of perfection, the Osmiae must all
emerge from the shaft by the only orifice which the bramble- stem
boasts, the orifice at the top. There is here but one obstacle, easy to
overcome: a plug of glued pith, of which the insect's mandibles make
short work. Down below, the stalk offers no ready outlet; besides, it is
prolonged underground indefinitely by the roots. Everywhere else is the
ligneous fence, generally too hard and thick to break through. It is
inevitable therefore that all the Osmiae, when the time comes to quit
their dwelling, should go out by the top; and, as the narrowness of the
shaft bars the passage of the preceding insect as long as the next insect,
the one above it, remains in position, the removal must begin at the top,
extend from cell to cell and end at the bottom. Consequently, the order
of exit is the converse to the order of birth: the younger Osmiae leave
the nest first, their elders leave it last.
The oldest, that is to say, the bottom one, was the first to finish her
supply of honey and to spin her cocoon. Taking precedence of all her
sisters in the whole series of her actions, she was the first to burst her
silken bag and to destroy the ceiling that closes her room: at least, that

is what the logic of the situation takes for granted. In her anxiety to get
out, how will she set about her release? The way is blocked by the
nearest cocoons, as yet intact. To clear herself a passage through the
string of those cocoons would mean to exterminate the remainder of the
brood; the deliverance of one would mean the destruction of all the rest.
Insects are notoriously obstinate in their actions and unscrupulous in
their methods. If the Bee at the bottom of the shaft wants to leave her
lodging, will she spare those who bar her road?
The difficulty is great, obviously; it seems insuperable.