Copy of a letter from Major Greenwood, junior to Sir David Bruce It would appear that Uganda trypanosomes are larger than the others but as the samples vary so much it is unsafe to draw firm conclusion. He encloses a table giving the probable error in calculation the size of different species of trypanosomes and a note of explanation of the uncertainty of the table showing the variations between Uganda and Zululand species of trypanosomes 19/7/1911