238 G. S. STENT 



I. Introduction 



Within a few years of Twort's (1915) and his own first description (d'Herelle, 

 1917) of a serially transmissible bacteriolytic principle, d'Herelle had under- 

 stood the fundamental nature of the multiplication of bacterial viruses. In 

 1926, d'Herelle thus summarized his earlier findings: "The first act of bacterio- 

 phagy consists in the approach of the bacteriophage corpuscle toward the 

 bacteria, then in the fixation of the corpuscle to the latter. . . . The 

 bacteriophage corpuscle penetrates into the interior of the bacterial cell. 

 When, as a result of its faculty of multiplication, the bacteriophage corpuscle 

 which has penetrated into the bacterium forms a colony of a number of 

 elements, the bacterium ruptures suddenly, liberating into the medium 

 young corpuscles which are then ready to continue the action (d'Herelle, 1920, 

 1921)." Far from gaining immediate acceptance, however, d'HereUe's ^'iews 

 found few followers among bacteriologists, "probably," wrote Burnet in 1934, 

 "because of the heterodox nature of these conceptions rather than from any 

 fault in d'HereUe's logic." Some of the early investigators of the bacteriophage, 

 such as Kabeshima (1920), and Bordet and Ciuca (1920), denied in fact the 

 existence of any phage "corpuscles" and believed that the only important 

 feature of bacteriophagy was the induction of bacterial lysis, a phenomenon 

 which they fancied to be caused by enzymes either secreted by an animal 

 host or endogenous to the bacteria themselves. Hence, from this standpoint, 

 the question of bacterial virus multiplication is not meaningful, the only real 

 problem being the mechanism of induction of lysis of the bacterial cells. 

 Other workers, while more or less accepting d'HereUe's notions of the self- 

 reproducing nature of the bacteriophage, thought, on the contrary, that "far 

 from being the product of lysis (the phage) is regenerated during the stage of 

 active multiplication of susceptible bacteria preceding the lysis. . . . Lysis 

 of the bacteria is merely a secondary phenomenon which may or may not 

 follow the accumulation of phage" (Bronfenbrenner, 1928). Krueger and 

 Northrop (1930) imagined, in fact that the bacteriophage freely passes into 

 and out of the bacterial ceUs, so that extra- and intraceUular phage particles 

 exist in a state of equilibrium with one another. 



For twenty years, "this controversy persisted with gradually diminishing 

 intensity but without the appearance of any unanimity," although "however 

 agnostic they may have been in regard to the nature of a phage, all workers 

 manipulated and in practice thought of it as an extrinsic virus-like agent" 

 (Burnet, 1934). The controversy finally subsided in the 1940's, when a new 

 generation of investigators took up the study of the mechanism of bacterial 

 virus multiplication more or less de novo. Most of the participants in this 

 latter-day renaissance of bacteriophage research confined their attention to 

 the study of one and the same group of bacterial viruses, the seven "T" phages 

 active on EschericMa coli (Demerec and Fano, 1945), and, in particular, to 



