70 SOCIAL SCIENTIST death in 14th and 15th century finally put paid to the ambitions of colonizers. The crusades of llth, 12th and 13th centuries to the Middle East met with the same fate. Apart from the fact that there was no unity among Christians and insufficient migrations, diseases played vital role in the failure of Europeans. Although Europe knew of Malaria, in the middle east, Europeans encountered different strains of Malaria parasite. They also had to cope with large number of people of equally high culture. Contrary to the above experiences the colonization of Canaries, Madeiras and Azores (islands in Atlantic Ocean) proved to be successful. Here the temperatures were moderate and there was no one to resist except for Gaunches in Canaries. Sheep were introduced in to the Azores in 15th century and they reproduced at a faster rate. Wheat was also introduced and shipped to Portugal. In Madeiras pigs and Cattle were introduced. Sugar was added and to cultivate Sugarcane, land had to be made appropriate for farming and irrigation which resulted in necessity of slaves. This requirement was met by Gaunches of Canaries, hence the first slaves were not blacks. Sugarcane production increased to a large extent and was being exported. Finally in Canaries the horse helped the conquest of the region. Guanches only knew of goats and pigs. Further Peste (Bubonic plague), Modorra (Typhoid), dolor de custado (Pneumonia) took heavy toll of them. These diseases were carried by the Europeans in to Canaries. The introduction of sugar here also necessitated the importation of American and African slaves to clear the large tracts of forests. The weeds from the New world took the place of forests. Ultimately the Guanches disappeared and the replacement of all these colonies was complete in the 16th century. From the above illustrations, the factors which were crucial for the success of European colonization, emerge as follows: (i) The prospective settlement should have similar climate to that of Europe, (ii) These lands had to be remote enough to remain free of pathogens characteristic of Old world which would render indigenes defenseless against the invaders and the remoteness would also ensure that the Old world animals and plants would survive there. Weeds, Animals and Ills as he calls them, proved to be instrumental in successful replacement of indigenes by the Europeans. The knowledge of winds and the expeditions of Columbus further accelerated the process of replacement. Yet certain areas, though with in reach, were beyond grasp. Middle east and East Asia were centres of high culture. Also in the New world tropics, the migrations were seldom successful. For example in Mexico, the population is interbred and not Neo European. In Africa Europeans could establish supremacy only towards the end of 19th century. Yet it was not a Neo Europe. The Africa had its own vegetation, diseases and a hostile