Some explanation may seem to be necessary to account for further research into the question of sugar tolerance in psychotic subjects, as it may be thought that this line of research has been exhausted by the numerous workers in this field. A study of their work, however, shows that no critical attempt has been made to correlate the result of the sugar tolerance test with the mental and physical state of the subject at the actual time of the test. Instead, groups of patients suffering from certain psychoses have been investigated, and the results reported as percentages of abnormal curves in such psychoses. Thus, when it has been reported that a certain percentage of melancholics or schizophrenics show sustained hyperglycæmia after glucose ingestion, no attempt has been made to find out in what way these differed from the remainder in whom normal sugar tolerance was found.