You who "shape the world to your whim," you will reply: "Doubtless there are no longer masters to-day; but go back to the first ages of the globe, when the world in its newness, as Lucretius has so superbly said, as yet knew neither bitter cold nor excessive heat (9/8.); an eternal springtide bathed the earth, and the insects, not dying, as to-day, at the first touch of frost, two successive generations lived side by side, and the younger generation could profit at leisure by the lessons of example." (9/9.) Let us return to Fabre's laboratory, to the covers of wire-gauze, and note what becomes, at the approach of winter, of the survivors of the vespine city. In the mild and comfortable retreat where the wasps are kept under observation they die no less, despite their well-being and all the care expended on them, when once "the inexorable hour" has struck, and once the exact capital of life which seems to have been imparted to them ages ago is exhausted. With no apparent cause, we see death busy among them. "Suddenly the wasps begin to fall as though struck by lightning; for a few moments the abdomen quivers and the legs gesticulate, then finally remain inert, like a clockwork machine whose spring has run down to the last coil." (9/10.) This law is general; "the insect is born orphaned both of mother and father, excepting the social insect, and again excepting the dung- beetle, which dies full of days." (9/11.) Moreover, Fabre is never weary of demonstrating that the insect, perfectly unconscious of the motive which makes it act, this thereby incapable of profiting by the lessons of experience and of innovation in its habits, beyond a very narrow circle. "No apprentices, no masters." In this world each obeys "the inner voice" on its own account; each sets itself to accomplish its task, not only without troubling as to what its neighbour is doing, but without thinking any further as to what it is doing itself; instance the Epeïra, turning its back on its work, yet "the latter proceeds of itself, so well is the mechanism devised"; and if by ill chance the spider acted otherwise it would probably fail. Darwin knew barely the tenth part of the colossal work of Fabre. He had read firstly in the "Annals of Natural Science" of the habits of the Cerceris and the fabulous history of the Meloidae. Finally he saw the first volume of the "Souvenirs" appear, and was interested in the highest degree by the beautiful study on the sense of location and direction in the Mason- bees. This was already more than enough to excite his curiosity and to make him wonder whether all his philosophy would not stumble over this obstacle. After having succeeded in explaining so luminously--and with what a lofty purview--the origin of species and the whole concatenation of animal forms, would it not be as though he halted midway in his task were the sanctuary of the origin of instinct to remain for ever inscrutable?