The valley of the Tagus divides two geological periods, and perhaps at one time divided Europe from a retiring Africa. Marked differences distinguish the fauna on either side of the river, and that of the north (with its 10,000 feet altitude) promised reward worthy the labours of investigation. Not a yard of that great mountain-land of Grédos has been trodden by British foot (save our own) since the days of Wellington. Hence it was an object with us to secure, not only ibex heads, but specimens of the smaller mammalia that dwell in those heights. Our mountain friends assembled round the camp-fire--twenty-five in all--each promised to take up this unaccustomed quest and to regard as game every hitherto unconsidered _bicho_ of the hills, whether feathered, furred, or scaled. If ibex failed us, at least a harvest in such minor game we meant to assure.[34] Three o'clock saw us astir, bathing in the dark burn while moonlight still streamed through sombre pines. Camp meanwhile was broken up; tents and gear packed on ponies and mules, breakfast finished--we were off, heavenwards. Then, just as the laden pack-animals filed through the burn, there rode up a man--he had ridden all night--and bore a message that changed our exuberant joy to grief--bad news from home. There could be no doubt--the writer must return at once. Within five minutes I had decided to make for a point on the northern railway beyond the hills and distant some sixty miles as the crow flies. Baggage and battery were abandoned; a handbag with a satchel of provisions and a wine-skin formed my luggage, and, leaving my companions in this wild spot, I set forth in the grey dawn on a barebacked mule devoid of saddle, bridle, or stirrups, and accompanied by two of our hill-bred lads, one riding pillion behind or running alongside in turn. Where the grey ramparts of the Risco del Fraile and the Casquerázo frown on a rugged earth below I parted with my old pals, they to continue the ibex-hunt, I on my mournful homeward way. Bee-eaters poised and chattered, brilliant butterflies (whose names I forgot to note), abounded as we rode along those fearful edges and boulder-studded steeps. Six hours of this brought us to a rock-poised hamlet of the sierra. The landlord of the _posada_ was also the _Alcalde_ (mayor) of the district, and even then presiding over a meeting of the council (_ayuntamiento_). Amidst dogs, children, fleas, and dirt, along with my two goat-herd friends, we made breakfast.