48 THOMPSON YATES AND JOHNSTON LABORATORIES REPORT 
3. T. evansi in blood agar cultures at 22° C. is living, but non-infective up to 
the nineteenth to twenty-second day. Three tubes at room temperature contain 
motile but non-infective parasites on the twenty-first, thirty-third, thirty-seventh 
days. 
4. T. gambiense of any strain is capable of living in a non-infective form 
in a first culture flask up to the thirty-fifth to fortieth days. Cultures in tubes and 
flasks, which on the twelfth to seventeenth days contained degenerating parasites, 
have by the addition of fresh culture fluid regained their vitality. Twice the 
contents of such tubes by transplanting to a fresh tube have lived to the forty-third 
day. One lived to the fifty-sixth day, and by a second transplant survived up to the 
sixty-eighth day. 
5. T. dimorphon in culture tubes and flasks is infective to animals up to the 
twenty-third day, when infected in large amounts. Sub-inoculated but non-infective 
cultures remain alive as long as the fifty-sixth day. In one case, two trypanosomes 
showing motion were found on the seventy-sixth day. 
6. In no case has any evidences of a toxine been noted in the inoculated 
animals. 
