r seven months'
upbringing on the mother's back? One conceives a notion of exudations
supplied by the bearer's body, in which case the young would feed on
their mother, after the manner of parasitic vermin, and gradually drain
her strength.

We must abandon this notion. Never are they seen to put their mouths to
the skin that should be a sort of teat to them. On the other hand, the
Lycosa, far from being exhausted and shrivelling, keeps perfectly well
and plump. She has the same pot-belly when she finishes rearing her
young as when she began. She has not lost weight: far from it; on the
contrary, she has put on flesh: she has gained the wherewithal to beget
a new family next summer, one as numerous as to-day's.

Once more, with what do the little ones keep up their strength? We do
not like to suggest reserves supplied by the egg as rectifying the
animal's expenditure of vital force, especially when we consider that
those reserves, themselves so close to nothing, must be economized in
view of the silk, a material of the highest importance, of which a
plentiful use will be made presently. There must be other powers at
play in the tiny animal's machinery.

Total abstinence from food could be understood, if it were accompanied
by inertia: immobility is not life. But the young Lycosae, though
usually quiet on their mother's back, are at all times ready for
exercise and for agile swarming. When they fall from the maternal
perambulator, they briskly pick themselves up, briskly scramble up a
leg and make their way to the top. It is a splendidly nimble and
spirited performance. Besides, once seated, they have to keep a firm
balance in the mass; they have to stretch and stiffen their little
limbs in order to hang on to their neighbours. As a matter of fact,
there is no absolute rest for them. Now physiology teaches us that not
a fibre works without some expenditure of energy. The animal, which can
be likened, in no small measure, to our industrial machines, demands,
on the one hand, the renovation of its organism, which wears out with
movement, and, on the other, the maintenance of the heat transformed
into action. We can compare it with the locomotive-engine. As the iron
horse performs its work, it gradually wears out its pistons, its rods,
its wheels, its boiler-tubes, all of which have to be made good from
time to time. The founder and the smith repair it, supply it, so to
speak, with 'plastic food,' the food that becomes e