the spring
births. I lodge these groups, one by one, in separate glass tubes, thus
forming a collection on which I can draw at will, while, in view of my
experiments, I keep under observation the whole swarm produced by one
caterpillar.

The adult Microgaster appears a fortnight later, in the middle of June.
There are fifty in the first tube examined. The riotous multitude is in
the full enjoyment of the pairing-season, for the two sexes always
figure among the guests of any one caterpillar. What animation! What an
orgy of love! The carnival of these pigmies bewilders the observer and
makes his head swim.

Most of the females, wishful of liberty, plunge down to the waist
between the glass of the tube and the plug of cotton-wool that closes
the end turned to the light; but the lower halves remain free and form
a circular gallery in front of which the males hustle one another, take
one another's places and hastily operate. Each bides his turn, each
attends to his little matters for a few moments and then makes way for
his rivals and goes off to start again elsewhere. The turbulent wedding
lasts all the morning and begins afresh next day, a mighty throng of
couples embracing, separating and embracing once more.

There is every reason to believe that, in gardens, the mated ones,
finding themselves in isolated couples, would keep quieter. Here, in
the tube, things degenerate into a riot because the assembly is too
numerous for the narrow space.

What is lacking to complete its happiness? Apparently a little food, a
few sugary mouthfuls extracted from the flowers. I serve up some
provisions in the tubes: not drops of honey, in which the puny
creatures would get stuck, but little strips of paper spread with that
dainty. They come to them, take their stand on them and refresh
themselves. The fare appears to agree with them. With this diet,
renewed as the strips dry up, I can keep them in very good condition
until the end of my inquisition.

There is another arrangement to be made. The colonists in my spare
tubes are restless and quick of flight; they will have to be
transferred presently to sundry vessels without my risking the loss of
a good number, or even the whole lot, a loss which my hands, my forceps
and other means of coercion would be unable to prevent by checking the
nimble movements of the tiny prisoners. The irresistible attraction of
the sunlight comes to my aid. If I lay one of my tubes horizontally on
the t