The religion of Islam spread rapidly amongst the Berbers, but it took a particular development, which shows a survival of many pre-Islamic religious ideas. The worship of saints and the devotion paid at their tombs is a corruption which appears elsewhere, on lines quite distinct from the Asiatic beliefs as to incarnation or transmigration, and in the west this saint worship takes an extreme form, although here and there are tribes which reject it altogether, as is the case with the B. Messara, the Ida of South Morocco, etc. Pilgrimages (_ziara_) are made to saints’ tombs, commemorative banquets are held there (_wa´da_ or _ta´an_), and acts of worship, often taking a revolting form, are paid to living saints, who are known as _murabits_ or _marabouts_, a word which literally means “those who serve in frontier forts (_ribat_),” where the soldiers were accustomed to devote themselves to practices of piety. These saints are also known as _sidi_ (lords), or _mulaye_ (teachers), and in the Berber language of the Twaregs as _aneslem_, or “Islamic.” Very often they are insane persons, and are allowed to indulge every passion and to disregard the ordinary laws of morality. Even those living at the present day are credited with miraculous powers, not only with gifts of healing, but with exemption from the limitations of space and from the laws of gravity (cf. Trumelet: _Les saints de l’islam_, Paris, 1881); in many cases the same saint has two or more tombs, and is believed to be buried in each, for it is argued that, as he was able to be in two or more places at once during life, so his body can be in several tombs after death. All this, of course, is no normal development of Islam, to which it is plainly repugnant. How thin a veneer of Muslim usages covers over a mass of primitive animism may be seen from Dr. Westermarck’s essay on “Belief in spirits in Morocco,” the firstfruits of the newly established Academy at Abo in Finland (_Humaniora._ I. i. Abo, Finland, 1920), and from Dr. Montet’s _Le culte des saints musulmans dans l’Afrique du nord_ (Geneva, 1905). Amongst the Berber tribes in perpetual conflict with the Arab garrisons there was always a refuge and a welcome for the lost causes of Islam, and so almost every heretical sect and every defeated dynasty made its last stand there, so that even now those parts show the strangest survivals of otherwise forgotten movements. No doubt this was mainly due to a perennial tone of disaffection towards the Arab rulers, and anyone in revolt against the Khalif was welcomed for that very fact.