Abstract
Resistance to streptomycin, of a degree exceeding 1000 µg. per ml., has been induced in sensitive strains of Hemophilus influenzae by exposure for 10 minutes to desoxyribonucleic acid-containing extracts isolated from a strain of type b Hemophilus influenzae which had emerged resistant to 1000 µg. of streptomycin per ml. DNA is essential for the process which brings out this change; the reaction can be prevented by destruction of the DNA with crystalline desoxyribonuclease.The resistant trait which is created in this way is heritable.