Seated on the dry hill-side here, by the belted blue Mediterranean, I have picked up from the ground a bit of blanched and moldering bone, well cleaned to my hand by the unconscious friendliness of the busy ants; and looking closely at it I recognize it at once, with a sympathetic sigh, for the solid welded tail-piece of some departed British tourist swallow. He came here like ourselves, no doubt, to escape the terrors of an English winter: but among these pine-clad Provençal summits some nameless calamity overtook him, from greedy kestrel or from native sportsman, and left him here, a sheer hulk, for the future contemplation of a wandering and lazy field-naturalist. Fit text, truly, for a sermon on the ancestry of birds; for this solid tail-bone of his tells more strangely than any other part of his whole anatomy the curious story of his evolution from some primitive lizard-like progenitor. Close by here, among the dry rosemary and large-leaved cistus by my side, a few weathered tips of naked basking limestone are peeping thirstily through the arid soil; and on one of these gray lichen-covered masses a motionless gray lizard sits sunning his limbs, in hue and spots just like the lichen itself, so that none but a sharp eye could detect his presence, or distinguish his little curling body from the jutting angles of the rock, to which it adapts itself with such marvelous accuracy.