THE SLEEPING SICKNESS 187 



phylloxera, to Europe ; and in three years half the vines 

 in France and Italy were destroyed by the phylloxera, 

 because the European vines had not been bred in associa- 

 tion with this little pest, and had not acquired the simple 

 adjusting faculty of throwing out new shoots. 



But it is not only by his reckless mixing up of incom- 

 patibles from all parts of the globe that the unscientific 

 man has risked the conversion of paradise into a desert. 

 In his greedy efforts to produce large quantities of animals 

 and plants convenient for his purposes, and in his eager- 

 ness to mass and organise his own race for defence and 

 conquest, man has accumulated unnatural swarms of 

 one species in field and ranch and unnatural crowds of 

 his own kind in towns and fortresses. Such undiluted 

 masses of one organism serve as a ready field for the 

 propagation of previously rare and unimportant parasites 

 from individual to individual. Human epidemic diseases 

 as well as those of cattle and crops, are largely due to this 

 unguarded action of the unscientific man. 



A good instance of this is seen in the history of the coffee 

 plantations of Ceylon, where a previously rare and obscure 

 parasitic fungus, leading an uneventful life in the tropical 

 forests of that country, suddenly found itself provided 

 with an unlimited field of growth and exuberance in the 

 coffee plantations. The coffee plantations were destroyed 

 by this parasite, which has now returned to its pristine ob- 

 scurity. Disharmonious, blundering man was responsible 

 for its brief triumph and celebrity. Dame Nature had 

 not allowed the coffee fungus more than a very moderate 

 scope. Man comes in and takes the reins ; disaster follows ; 

 and there is no possibility of return to the old regime. 

 Man must make his blunders and retrieve them by further 

 interference by the full use of his intelligence, by the 

 continually increasing ingenuity of his control of the 



