2 NOETH-EAST APRIOA. 



90 miles broad, to the Asiatic mainland. Even this isthmus itself is an old marine 

 and fluvial basin — Mediterranean alluvium in the north, a deposit of the Red Sea in 

 the south ; between these two marine zones an ancient Nilotic delta, which, to judge 

 from the allied faunas, probably at one time communicated with the Jordan. But 

 although the Isthmus of Suez had no existence in Tertiary times, there were other 

 stretches of land connecting Egypt with Cyprus and Syria ; for nowhere else in the 

 periphery of the globe are there found contiguous marine inlets presenting such 

 differences in their fauna as do those of Suez and Gaza. 



But if the waters of the Indian Ocean have remained completely distinct from 

 those of the Mediterranean since the Eocene epoch, with the exception perhaps of a 

 shallow channel flooded in Quaternary times, the intervening barrier has at last 

 been removed by the hand of man. Thanks to his industry, the two seas hence- 

 forth mingle their waters in the inland basin of Lake Timsah, and the circumnavi- 

 gation of Africa is open to the largest vessels afloat. Compared with this southern 

 continent, whose contour is so clearly defined, the two other divisions of the Old 

 World seem to merge in one continental mass. Certainly the depression skirting 

 the Ural range from the Gulf of Ob to the Caspian, and the Manich isthmus between 

 the Caspian and Euxine, cannot be regarded as such sharp geographical parting 

 lines as the marine channel now flowing between Suez and Port Said. 



But however clearly severed at present from the rest of the Eastern hemisphere, 

 Africa is not so entirely distinct from Europe and Asia as might at first sight be 

 supposed. Parts of its seaboard were even formerly connected directly with the 

 regions beyond the Mediterranean, and there was a time when the Atlas Mountains 

 effected a junction across the present Strait of Gibraltar with the parallel Sierra 

 Nevada range. Even down to the close of the Pliocene epoch, Tunisia was still 

 united with Sicily and Italy through a broad zone, of which the only surviving 

 fragments are the little Maltese group of islets. Greece also merged southwards in 

 boundless plains watered by streams whose banks were frequented by the elephant 

 and hippopotamus.* 



Although now detached from Spain and Italy, North-west Africa is still in its 

 geology, natural history, and climate essentially a Mediterranean land, forming with 

 the opposite European seaboard a distinct physical region. Along both coasts the 

 same fossils occur on the old rocks, while similar floras and faunas are now in 

 possession of the soil. The Mauritanian coastlands differ far more from Nigretia, 

 from which they are separated by the Sahara, than they do from Provence, and as 

 already remarked by Sallust, North Africa is physically a part of Europe. East- 

 wards also the Ethiopian shore of the Ped Sea belongs to the same formations as the 

 opposite coast of Arabia, and a general resemblance characterises the climate, 

 natural productions, and inhabitants on either side of Bab-el-Mandeb. 



In its massive outlines Africa presents the same monotonous appearance as the 

 two other southern divisions of the globe — South America and Australia. It is even 

 less indented than the corresponding section of the New World ; nor is it supple- 

 mented, like Australia, by a vast region of archipelagoes and islands, scattered over 



* Ramsay ; Zittal ; Neumayr. 



