The reader should by now have a fair idea of the nature and extent of bacteriophage biology; the way in which it is conducted; some of its achievements and ambitions. A selective bibliography is appended for those who wish to study it further. For anyone who has not yet read biology or biochemistry up to degree standard, Stent’s ‘Molecular Genetics’ is strongly recommended, and Mathews’ ‘Bacteriophage Biochemistry’ for the more erudite. After that, the phage literature being so vast, some measure of specialisation is advisable, if not already dictated by individual circumstances. The student may be fortunate enough to find a review of his particular field of interest in one of the specialised review journals such as ‘Bacteriological Reviews’, ‘Annual Review of Microbiology’ or ‘Advances in Virus Research’. To keep abreast of current events it is advisable to read at least one virological journal thoroughly, ‘Journal of General Virology’ say or ‘Virology’ and to maintain surveillance of the rest by means of ‘Current Contents’, a journai that simply lists the titles of papers in other journals.