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

CHAPTER XI.THE ETHIOPIAN REGION.This is one of the best defined of the great zoological regions,consisting of tropical and South Africa, to which must be addedtropical Arabia, Madagascar, and a few other islands, all popularlyknown as African. Some naturalists would extend theregion northwards to the Atlas Mountains and include the wholeof the Sahara ; but the animal life of the northern part of thatgreat desert seems more akin to the Palsearctic fauna of NorthAfrica. The Sahara is really a debatable land which has beenpeopled from both regions;and until we know more of the naturalhistory of the great plateaus which rise like islands in the wasteof sand, it will be safer to make the provisional boundary line ator near the tropic, thus giving the northern half to the Palsearctic,the southern to the Ethiopian region. The same line may becontinued across ArabiaWith our present imperfect knowledge of the interior ofAfrica, only three great continental sub-regions can be well defined.The open pasture lands of interior tropical Africa arewonderfully uniform in their productions ; a great number ofspecies ranging from Senegal to Abyssinia and thence to theZambesi, while almost allthe commoner African genera extendover the whole of this area. Almost all this extensive tract ofcountry is a moderately elevated plateau, with a hot and dryclimate, and characterised by a grassy vegetation interspersedwith patches of forest. This forms our first or East Africansub-region. The whole of the west coast from the south side ofthe Gambia Paver to about 10° or 12° south latitude, is a very