Mid-April comes and the little glass tubes in which I store my animal seeds are full of life. The black germs are the first to hatch; a fortnight later the red ones follow suit. The epidermic boxes undergo a process of self-mutilation, the front part falling off and leaving a gaping void, without other change of form. A minute animal comes out of them, a black speck in which the lens recognizes a very shapely little Louse, bearing the regulation sucker pressed against its thorax. My first thoughts were correct: the puzzling little red and black bodies found under the lichens and in the cracks of dead wood were really Louse-seeds. And these seeds, judging by their husks, endowed with a head and legs, are little insects, first active and then inert and converted into germs. The original, almost integral substance is reborn in another shape. The little creature’s skin has provided the shell, the segmented box, a jet-black or amber-yellow pellicule; the rest is concentrated into an egg. The time has not come to observe the singular creature’s origin and behaviour; chronological order forbids. Let us return to the vermin issuing from these germs. They are tiny, tiny little black Lice, with flat abdomens, plainly segmented and as it were granular. Assiduous observation through the lens shows them to be dusted with a touch of blue-grey powder like the bloom on a plum. Trotting with little steps about their spacious prison, the glass tube, they seem uneasy. What do they want? What are they looking for? No doubt, a camping-ground on the friendly tree. I come to their assistance; I place in the tube a twig of terebinth whose buds are beginning to open at the top of their scaly covering. This is the thing they wanted. They climb up the twig, establish themselves in the velvet that clothes the tips of the buds, and there they settle, calm and satisfied. Direct observations made on the terebinth are accompanied, pari passu, by laboratory experiments. The little black Lice, rare on the 15th of April, are numerous ten days later. On the tip of a single bud I count over twenty of them; and most of the buds are colonized, or at least those that are largest and farthest from the ground. The occupants remain hidden in the scanty down of the nascent follicles whose tips are barely emerging. After a sojourn of some days, when the leaves begin to appear, each insect makes for itself a private dwelling. It exploits, with its sucker, a leaflet whose tip turns purple, swells up and curls over, and, bringing its edges together, forms a flat pocket with an irregular opening. Each of these pockets, about the size of a grain of hemp-seed, is a tent in which a black Plant-louse takes up her residence: one only, never more.