This volume is the third in the series devoted to Antibiotics initiated by Springer Verlag in 1967. The first two volumes were devoted to the Mode of Action of Antibiotics and Biogenesis, respectively and were received graciously. During the intervening years these two works have been used often by research workers and students alike and have been quoted extensively. Although a number of other excellent treatises on antibiotics have appeared, the Springer series has set a standard for thoroughness and quality that meets the need of the scientific community. It is against this background that...