344 



ANNUAL REPORT SMITHSONIAN INSTITUTION,, 1942 



In British North Borneo, researches, not yet completed and not yet 

 published, by Dr. John McArthur, whom I am proud to claim as a 

 pupil, indicate that the dangerous anopheles of Malaya may not be 

 carrying the disease. A. leucosphyrus, a mosquito that lives at the 

 headwaters of streams in dense jungle, has been proved to be the im- 

 portant carrier in an intensely malarial area. It may be that merely 

 clearing the undergrowth, and allowing cattle to keep the undergrowth 

 down, will eliminate the disease, at little cost to the poor and half- 

 starved inhabitants. 



Jan. Feb. Ma.r. Jlpn Ti/tay JuTie July Jlug. Sept. Oct. ^w. Dee. 



FiGUBE 1. — Mean monthly death rate in Singapore from all causes. 



In the Philippine Islands the picture changes again. Here, as in the 

 coastal plains of the Malay Peninsula, Java and Borneo, Siam and 

 Burma, the rice fields are healthy. In the Philippine Islands the man- 

 grove zone is also healthy, unlike Java and Sumatra. But along the 

 foothills A. minimus breeds among grass in slowly moving clear water 

 and produces intense malaria. This mosquito is one of the great car- 

 riers of malaria, for it carries the disease not merely in the Philippine 

 Islands, but extensively in the continent of Asia: in French Indo- 

 China, in Siam, on the Burma Eoad, and not least in the great Assam 

 Valley of northern India. To it is due the deadly Terai malaria and 

 blackwater fever in the area along the foothills of the eastern half of 

 the Himalayas in India. The brilliant researches of G. C. Eamsay, 

 Deputy Director of the Boss Institute (1936), have proved this. His 

 equally brilliant prevention of the disease is not sufficiently known. 

 It is sheer white magic to wipe deadly malaria from a valley by grow- 

 ing a hedge of wild rhododendron or wild privet over a little stream, 

 without interfering with the growth of the rice in the more stagnant 



