THE most important factor in the history of West Africa has been its unhealthiness, or rather deadliness. To this deadliness the disease of Malaria was the chief contributor, but by no means the only one. Malaria was endemic in the region from the earliest times. The adult natives through long experience had acquired immunity, but the Europeans on arriving there died like flies, and the Coast gained a very sinister reputation. l Moreover, to the terror of death was added the horror of mystery. No one knew exactly what was the cause of the disease, although the theories were many.