The substance of the terrestrial human body is due to the elements of our planet, and notably to carbon. The terrestrial human form derives from the ancestral animal forms to which it has gradually raised itself by the continuous progress of the transformation of species. To us it seems obvious that we are man or woman, because we have a head, a heart, lungs, two legs, two arms, and so on. Nothing is less a matter of course. That we are constituted as we are, is simply the result of our pro-simian ancestors having also had a head, a heart, lungs, legs, and arms--less elegant than your own, it is true, Madam, but still of the same anatomy. And more and more, by the progress of paleontology, we are delving down to the origin of beings. As certain as it is that the bird derives from the reptile by a process of organic evolution, so certain is it that terrestrial Humanity represents the topmost branches of the huge genealogical tree, whereof all the limbs are brothers, and the roots of which are plunged into the very rudiments of the most elementary and primitive organisms. The multitude of worlds is surely peopled by every imaginable and unimaginable form. Terrestrial man is endowed with five senses, or perhaps it is better to say six. Why should Nature stop at this point? Why, for instance, may she not have given to certain beings an electrical sense, a magnetic sense, a sense of orientation, an organ able to perceive the ethereal vibrations of the infra-red or ultra-violet, or permitted them to hear at a distance, or to see through walls? We eat and digest like coarse animals, we are slaves to our digestive tube: may there not be worlds in which a nutritive atmosphere enables its fortunate inhabitants to dispense with this absurd process? The least sparrow, even the dusky bat, has an advantage over us in that it can fly through the air. Think how inferior are our conditions, since the man of greatest genius, the most exquisite woman, are nailed to the soil like any vulgar caterpillar before its metamorphosis! Would it be a disadvantage to inhabit a world in which we might fly whither we would; a world of scented luxury, full of animated flowers; a world where the winds would be incapable of exciting a tempest, where several suns of different colors--the diamond glowing with the ruby, or the emerald with the sapphire--would burn night and day (azure nights and scarlet days) in the glory of an eternal spring; with multi-colored moons sleeping in the mirror of the waters, phosphorescent mountains, aerial inhabitants,--men, women, or perhaps of other sexes,--perfect in their forms, gifted with multiple sensibilities, luminous at will, incombustible as asbestos, perhaps immortal, unless they commit suicide out of curiosity? Lilliputian atoms as we are, let us once for all be convinced that our imagination is but sterility, in the midst of an infinitude hardly glimpsed by the telescope.