although ignorance and natural obstacles impede the progress of new ideas, the whole of the black race is gradually adopting the new religion and developing Arab characteristics.  In the districts of the north, where the original invaders settled, the evolution is complete, and the Arabs of the Soudan are a race formed by the interbreeding of negro and Arab, and yet distinct from both.  In the more remote and inaccessible regions which lie to the south and west the negro race remains as yet unchanged by the Arab influence.  And between these extremes every degree of mixture is to be found.  In some tribes pure Arabic is spoken, and prior to the rise of the Mahdi the orthodox Moslem faith was practised.  In others Arabic has merely modified the ancient dialects, and the Mohammedan religion has been adapted to the older superstitions; but although the gap between the Arab-negro and the negro-pure is thus filled by every intermediate blend, the two races were at an early date quite distinct.

The qualities of mongrels are rarely admirable, and the mixture of the Arab and negro types has produced a debased and cruel breed, more shocking because they are more intelligent than the primitive savages.  The stronger race soon began to prey upon the simple aboriginals; some of the Arab tribes were camel-breeders; some were goat-herds; some were Baggaras or cow-herds.  But all, without exception, were hunters of men.  To the great slave-market at Jedda a continual stream of negro captives has flowed for hundreds of years.  The invention of gunpowder and the adoption by the Arabs of firearms facilitated the traffic by placing the ignorant negroes at a further disadvantage.  Thus the situation in the Soudan for several centuries may be summed up as follows:  The dominant race of Arab invaders was unceasingly spreading its blood, religion, customs, and language among the black aboriginal population, and at the same time it harried and enslaved them.

The state of society that arose out of this may be easily imagined.  The warlike Arab tribes fought and brawled among themselves in ceaseless feud and strife.  The negroes trembled in apprehension of capture, or rose locally against their oppressors.  Occasionally an important Sheikh would effect the combination of many tribes, and a kingdom came into existence —­a community consisting of a military class armed with guns and of multitudes of slaves, at once their servants and their merchandise, and sometimes trained as soldiers.  The dominion might prosper viciously till it was overthrown by some more powerful league.

All this was unheeded by the outer world, from which the Soudan is separated by the deserts, and it seemed that the slow, painful course of development would be unaided and uninterrupted.  But at last the populations of Europe changed.  Another civilisation reared itself above the ruins of Roman triumph and Mohammedan aspiration—­a civilisation more powerful, more glorious, but no less aggressive.