The absorbability of surgical gut (newly adopted U. S. P. term to designate sheep intestine prepared for surgical use, instead of the misnomer "catgut") has been a somewhat controversial subject. One of the purposes of this work on absorbability was to ascertain the decline in the tensile strength in the tissues of plain and chromic catgut available from different manufacturers. In 1928, Howes1 reported his observations on the loss of strength of catgut when embedded in the tissues. The most complete review of earlier studies on catgut was presented by Rhoads, Hottenstein and Hudson2 in 1937 along with clinical and experimental observations on the decline in the strength of catgut after exposure to living tissues. Further clinical studies on the loss of strength of catgut also were published that same year by one of us (H. P. J.).3 In 1939, Wolff and Priestley4 made a comprehensive