274 OUR INSECT FRIENDS AND FOES 



spreads rapidly and is at first severe. After 

 some years the survivors become immune or 

 partially so. But the children become infected 

 soon after birth, and continue to be diseased for 

 some years, gradually becoming immune. This 

 is the condition of every village in every highly 

 malarious district ; the adults are immune, the 

 children are nearly all of them full of malaria 

 parasites." 



It is a curious and interesting fact that there 

 is a singular similarity of effect on mankind, 

 between malaria and influenza, an effect in which 

 they differ from most diseases, for neither tend 

 to strengthen a nation by weeding out the 

 physically unfit, but rather to produce a general 

 lowering of the vitality of the people, without a 

 very heavy death-rate. The effects of malaria 

 on its victims is to unfit them for strenuous work 

 or prolonged manual labour, and consequently 

 to diminish generally their producing powers ; 

 while if left to itself an area so attacked tends 

 towards moral and physical degradation. 



And now let us try to realize the important 

 part which this insidious disease, spread by the 

 Anopheline mosquitos, appears to have played 

 in the downfall of ancient Greece and Rome. 

 We know that prior to 400 B.C. Greece was at 

 the height of her fame and glory socially, artisti- 

 cally, and philosophically and prior to that 

 date we find no very definite statement of the 

 presence of malaria, at any rate to a serious 

 extent. But from 400 B.C. onwards, a change 

 gradually came over the Greek character. 

 Patriotism, pride of citizenship, religion, simple 



