222 Master Minds of Modern Science 



Then friends in London interceded with the India Office 

 on behalf of Ross, and in January 1898 he was placed on 

 special duty for six months to enable him to take up 

 again his malaria research work, now at so promising a 

 stage. 



He went to Calcutta, where human malaria is scarce, 

 and there he settled down to work out with bird malaria 

 the complete cycle of infection. 



By March Ross had found the species of mosquito 

 capable of carrying the malaria parasite of birds, and 

 within a few more weeks he had traced step by step the 

 parasite's development from the moment when it entered 

 the mosquito until the moment it was found in the body 

 of the infected bird. In the course of these experiments 

 Ross gave malaria to twenty-three out of twenty-eight 

 captive birds, none of which could have been infected by 

 any means save the mosquitoes which were placed under 

 the nets of their cages. 



At last Ross knew just how malarial fever was spread; 

 the sequence of events had been explored from beginning 

 to end. On March 21st, 1898, Ross wrote home to Manson : 



My wish is that you were here to share with me the pleasure 

 which I have experienced yesterday and to-day in seeing your 

 induction verified step by step. Such pleasure comes to but 

 few men, I fancy, though you must have felt it in regard to 

 filaria [elephantiasis]. I am producing pigmented cells ad 

 libitum by feeding grey mosquitoes on larks infected with 

 proteosoma. This, of course, means the solution of the malaria 

 problem. 



When the news of this further success reached London 

 the British Medical Association was about to hold its 

 annual meeting at Edinburgh. It was at this meeting, in 

 July 1898, that Sir Patrick Manson announced to the 

 medical world the discoveries which Ross had made, and 

 he showed for the first time the slides he had received 



