e two functions of the wadding are here plainly marked. The delicate
skin of the larvae needs a well-padded cradle; and the mother collects
the softest materials that the cottony plants provide. Rivalling the
bird, which furnishes the inside of the nest with wool and strengthens
the outside with sticks, she reserves for the grubs' mattress the finest
down, so hard to find and collected with such patience. But, when it
becomes a matter of shutting the door against the foe, then the entrance
bristles with forbidding caltrops, with stiff, prickly hairs.

This ingenious system of defence is not the only one known to the
Anthidia. More distrustful still, the Manicate Anthidium leaves no space
in the front part of the reed. Immediately after the column of cells,
she heaps up, in the uninhabited vestibule, a conglomeration of rubbish,
whatever chance may offer in the neighbourhood of the nest: little
pieces of gravel, bits of earth, grains of sawdust, particles of mortar,
cypress-catkins, broken leaves, dry Snail-droppings and any other
material that comes her way. The pile, a real barricade this time,
blocks the reed completely to the end, except about two centimetres
(About three-quarters of an inch.--Translator's Note.) left for the
final cotton plug. Certainly no foe will break in through the double
rampart; but he will make an insidious attack from the rear.
The Leucopsis will come and, with her long probe, thanks to some
imperceptible fissure in the tube, will insert her dread eggs and
destroy every single inhabitant of the fortress. Thus are the Manicate
Anthidium's anxious precautions outwitted.

If we had not already seen the same thing with the Leaf-cutters, this
would be the place to enlarge upon the useless tasks undertaken by the
insect when, with its ovaries apparently depleted, it goes on spending
its strength with no maternal object in view and for the sole pleasure
of work. I have come across several reeds stopped up with flock though
containing nothing at all, or else furnished with one, two or three
cells devoid of provisions or eggs. The ever-imperious instinct
for gathering cotton and felting it into purses and heaping it into
barricades persists, fruitlessly, until life fails. The Lizard's tail
wriggles, curls and uncurls after it is detached from the animal's body.
In these reflex movements, I seem to see not an explanation, certainly,
but a rough image of the industrious persistency of the insect, still