In recent years bacteriocins, especially colicins, have become widely known to molecular biologists as proteins with peculiar ways of killing bacteria. These same bacteriocins have been known for a long time to bacteriology for their unusual activity spectra and enormous variety. In this monograph I have attempted to bring together our detailed knowledge of those few bacteriocins which have already re ceived attention from molecular biologists, and our less detailed hut extensive knowledge of the variety of bacteriocins which exist. The field has been reviewed in whole or in part, by several...