Page:Popular Science Monthly Volume 8.djvu/685

This page has been validated.

haps the chionis is descended therefrom, and its liking for man is an inherited tendency.

Mr. Darwin exactly expressed the present attitude of this bird to science, as long ago as the voyage of the Beagle. He found a bird in Patagonia (Thinochorus rumicivorus) which "nearly equally partakes of the characters, different as they are, of the quail and snipe," and in this connection proceeds to remark: "A bird of another closely-allied genus, Chionis alba is an inhabitant of the antarctic regions; it feeds on seaweed and shells on the tidal rocks. . . . This small family of birds is one of those which from its varied relations to other families, although at present offering only difficulties to the systematic naturalist, ultimately may assist in revealing the grand scheme, common to the present and past ages, on which organized beings have been created."



AMONG the most revolutionary of the geographical schemes of the day are the projects of flooding portions of the African Sahara, and thus restoring to the sea what was once an integral part of it. In the Pliocene period, according to Sir Charles Lyell, the great desert was under water between latitudes 20° and 30° N., so that the southeastern part of the Mediterranean communicated with that portion of the Atlantic now bounded by the west coast of Africa. This is indicated not only by the presence of marine shells and other remains throughout the Sahara, but also by the radical difference between the fauna and flora north and south of it. What was formerly separated by a barrier of water is now separated by a barrier of sand.

There are two principal depressions in the Sahara, the basin called El-Juf, in the Sahel, north of the Middle Niger, which covers an area of about 126,000 square miles, and that of the shotts in the Algerian Sahara.

Mr. Donald Mackenzie, a British engineer, who has investigated the former depression, affirms that a long valley extends from its northwest corner to the Atlantic coast opposite the Canary Islands. It is only necessary, he argues, to cut through the accumulated sands at its mouth, which is laid down on the maps as the river Belta, to let in the waters and flood the entire basin. This scheme, advocated by Mr, J. A. Skertchly, General Sir Arthur Cotton, and others, will probably result in a thorough exploration of that part of the Sahara and its alleged outlet. The other project is in a more advanced state.

The depression of the shotts lies at the foot of the Aures Mountains,