So sacred are the persons of these teachers esteemed, that they pass without molestation through the countries of chiefs, not only hostile to each other, but engaged in actual warfare. Such deference is not only paid to them in Muhammadan countries, but also in the pagan villages in which they establish their schools, where the people respect them as the instructors of their children, and look upon them as the medium between themselves and Heaven, either for securing a supply of their necessities, or for warding off or removing calamities. [1168] Many of these teachers have studied in the mosques of Qayrwān, Fas, Tripoli [1169] and other centres of Muslim learning; but especially in the mosque of al-Azhar in Cairo. Students flock to it from all parts of the Muslim world, and among them is often to be found a contingent from Negro Africa,—students from Darfur, Wadai and Bornu, and some who even make their way on foot from the far distant West Coast; when they have finished their courses of study in Muslim theology and jurisprudence, there are many of them who become missionaries among the heathen population of their native land. Schools are established by these missionaries in the towns they visit, which are frequented by the pagan as well as the Muslim children. They are taught to read the Qurʼān, and instructed in the doctrines and ceremonies of Islam. Having thus gained a footing, the Muhammadan missionary, by his superior knowledge and attainments, is not slow to obtain great influence over the people among whom he has come to live. In this he is aided by the fact that his habits and manner of life are similar in many respects to their own, nor is he looked upon with suspicion, inasmuch as the trader has already prepared the way for him; and by intermarriage with the natives, being thus received into their social system, his influence becomes firmly rooted and permanent, and so in the most natural manner he gradually causes the knowledge of Islam to spread among them. His propagandist efforts are further facilitated by the fact that the deism which forms the background of the religious consciousness of many fetish-worshippers may pass by an easy transition into the theism of Islam, together with some other aspects of their theology, while their general outlook upon life and several of their religious institutions are capable of taking on a Muslim colouring and of being transferred to the new system of faith without undergoing much modification. [1170]