THE ROOTS OF EMPIRE 39 



chiefly malaria, have played a great — a very great 

 part in the Natural and Political History of Man. 

 Where malaria is mild, as in certain parts of North 

 America, it is a great deterrent, though not a com- 

 plete bar to alien immigration. Where it is viru- 

 lent, as in the Terai and on the West Coast of 

 Africa, it acts as an absolute check to colonisation.^ 

 In such countries, in exceptional instances, strangers 

 from non-malarial regions, when helped by drugs, 

 may survive for years ; but as a rule they perish 

 early. In any case, they are unable to rear families. 

 It is improbable, therefore, that the races inhabit- 



1 "Yet remember, before you elect to cast your lot in with the 

 West Coasters, that 85 per cent, of them die of fever, or return home 

 with their health permanently wrecked. Also remember there is no 

 getting acclimatised to the Coast. There are, it is true, a few men out 

 there who, although they have been resident in West Africa for years, 

 have never had fever, but you can count them up on the fingers of one 

 hand. There is another class who have been out for twelve months 

 at a time, and have not had a touch of fever ; these you want the 

 fingers of your two hands to count, but no more. By far the largest 

 class is the third, which is made up of those who have a slight doze 

 of fever once a fortnight, and some day, apparently for no extra 

 reason, get a heavy dose and die of it. A very considerable class 

 is the fourth — those who die within a fortnight to a month of going 

 ashore. 



" The fate of a man depends solely on his power of resisting the 

 so-called malaria, not in his system becoming inured to it. The 

 first class of men that I have cited have some unknown element in 

 their constitutions that renders them immune. . With the second 

 class the power of resistance is great, and can be renewed from 

 time to time by a spell home in an European climate. In the 

 third class the state is that of cumulative poisoning ; in the fourth, of 

 acute poisoning."— " Travels in West Africa," by Mary H. Kingsley, 

 pp. 526-7. Macmillan & Co. Vide Appendix E. 



