This book is based on Hans Zahner's Biologie der Antibiotica, published in 1965. There is a vast literature on antibiotics, covering chemical, phar macological, and clinical aspects. We have made no attempt to cover this literature comprehensively. Our effort is directed toward discuss ing antibiotics as biological agents. They are substances produced by living cells, yet they are able to inhibit the growth of living cells - in many cases even the cells that produce them. We have taken this apparent biological paradox as our point of departure and have tried to look in this light at the...