llimetres. (.117 to .156 inch.--Translator's Note.)
The two sexes are equally numerous and wear the same costume, a black
uniform, all but the legs, which are pale red. In spite of this
likeness, they are easily distinguished. The male has an abdomen which
is slightly flattened and, moreover, curved at the tip; the female,
before the laying, has hers full and perceptibly distended by its
ovular contents. This rapid sketch of the insect should be enough for
our purpose.

If we wish to know the grub and especially to inform ourselves of its
manner of living, it is advisable to rear in a cage a numerous herd of
Cabbage-caterpillars. Whereas a direct search on the cabbages in our
garden would give us but a difficult and uncertain harvest, by this
means we shall daily have as many as we wish before our eyes.

In the course of June, which is the time when the caterpillars quit
their pastures and go far afield to settle on some wall or other, those
in my fold, finding nothing better, climb to the dome of the cage to
make their preparations and to spin a supporting network for the
chrysalid's needs. Among these spinners we see some weaklings working
listlessly at their carpet. Their appearance makes us deem them in the
grip of a mortal disease. I take a few of them and open their bellies,
using a needle by way of a scalpel. What comes out is a bunch of green
entrails, soaked in a bright yellow fluid, which is really the
creature's blood. These tangled intestines swarm with little lazy
grubs, varying greatly in number, from ten or twenty at least to
sometimes half a hundred. They are the offspring of the Microgaster.

What do they feed on? The lens makes conscientious enquiries; nowhere
does it manage to show me the vermin attacking solid nourishment, fatty
tissues, muscles or other parts; nowhere do I see them bite, gnaw, or
dissect. The following experiment will tell us more fully: I pour into
a watch-glass the crowds extracted from the hospitable paunches. I
flood them with caterpillar's blood obtained by simple pricks; I place
the preparation under a glass bell-jar, in a moist atmosphere, to
prevent evaporation; I repeat the nourishing bath by means of fresh
bleedings and give them the stimulant which they would have gained from
the living caterpillar. Thanks to these precautions, my charges have
all the appearance of excellent health; they drink and thrive. But this
state of things cannot last long. Soon ripe for the tran