The geographical distribution of animals, with a study of the relations ...

chai\ x.] THE PAL^IARCTIC REGION. 201In addition to the territories now indicated as forming partof the Mediterranean sub-region, we must add the group ofCanary Islands off the west coast of Africa which seem to bean extension of the Atlas mountains, and the oceanic groups ofMadeira and the Azores ; the latter about 1,000 miles from thecontinent of Europe, yet still unmistakably allied to it both intheir vegetable and animal productions. The peculiarities of thefaunas of these islands will be subsequently referred to.It seems at first sight very extraordinary, that so large andwide a sea as the Mediterranean should not separate distinctfaimas, and this is the more remarkable when we find how verydeep the Mediterranean is, and therefore how ancient we maywell suppose it to be. Its eastern portion reaches a depth of2,100 fathoms or 12,600 feet, while its western basin is about1,600 fathoms or 9,600 feet in greatest depth, and a considerablearea of both basins is more than 1,000 fathoms deep. But afurther examination shows, that a comparatively shallow sea orsubmerged bank incloses Malta and Sicily, and that on theopposite coast a similar bank stretches out from the coast ofTripolileaving a narrow channel the greatest depth of which is240 fathoms. Here therefore is a broad plateau, which anelevation of about 1,500 feetof land connecting Italy with Africa ;would alsowould convert into a wide extentwhile the same elevationconnect Morocco with Spain, leaving two extensivelakes to represent what is now the Mediterranean Sea, and affordingfree communication for laud animals between Europe andNorth Africa. That such a state of things existed at a comparativelyrecent period, is almost certain ; not only because aconsiderable number of identical species of mammalia inhabit theopposite shores of the Mediterranean, but also because numerousremains of three species of elephants have been found in cavesin Malta,—now a small rocky island in which it would be impossiblefor such animals to live even if they could reach it.Remains of hippopotami are also found atGibraltar, and manyother animals of African types in Greece ; all indicating meansof communication between South Europe and North Africa whichno longer exist. (See Chapter VI. pp. 113—115.)Vol. I.—15