Letter from Andrew Balfour, Director, Wellcome Tropical Research Laboratories, Khartoum to Ross, and note of mosquito statistics, May to December 1904 The information on his work is all in the Wellcome Laboratory reports and Ross ought to have received copies. Encloses some statistics and that the operations are not proving expensive. He hopes to try out a new drug against cattle trypanosomiasis 11/12/1904