In the above series of cases the organism of the infectious diarrhea group was isolated in 55 per cent of the cases. Agglutinins for the dysentery group were found in 12 per cent of the cases which were found to be negative from the bacteriological examination and a characteristic smear, as stained by Gram's method, with a typical history in 25 per cent of the other cases.
The intracutaneous reaction, on the other hand, showed 100 per cent negative results in the control cases. In cases with history of infectious diarrhea positive reactions were obtained in 85 per cent of the cases.
I wish to thank Dr. Henry I. Bowditch, chief of the visiting staff of the Boston Floating Hospital for the free use of the clinic and wards, as well as for the many helpful suggestions which he has given me and also Dr. Cleveland Floyd for his valuable aid and advice.