Aug. 19, 1922] THE BACTERIOPHAGE. [MBlrcAfjoTK.u 



ysant, C.R. Soc. Biologie, Ixxxiii, February 28th, 1920, p. 219. *^Le bacteriophage de 

 d'Herelle, sa reproduction, son interpretation, C.R. Soc. Biologie, Lxxxiii, October 9th, 1920, 

 p. 1296. 'On the influence of the tissue enzymes on the bacteriophage principle. Proceed. 

 Exp. Biol, and Med., xviii, April 20th, 1 21, p. 222. sAntagonisme microbien et lyse trans- 

 missible, C.R. Soc. Biologie, Ixxxvi, March 18th, 1922, p. 569 ''Autobacteriolysne et le 

 phenomene de d'HereUe, C.R. Soc.Biologie, Ixxxvi, April 29th, 1922, p. 833. '^Bakerio- 

 phagen Wirkungen gegen Flexner- imd Koli-Bakterien, Wien. klin. Woch., xxxiv. No. 37, 

 September 15th, 1921. '^Uber die Natur des d'Herelle'schen Bakteriophagen, Deut. vied. 

 Woch., No. 21, 1922. ^'Sur un microbe invisible, antagoniste des bacilles dysenteriques, 

 C.R. Acad, des Sciences, clxv, September 10th, 1917, p. 373. ^o^xsudats leucocytaires et 

 autolyse microbienne transmissible, C.R. Soc. Biologie, Ixxxiii, October 9th, 1920, p. 1293. 

 "L'ultramicrobe bacteriophage, C.R. Soc. Biologie, October 29th, 1921, p. 721. i-An 

 investigation on the nature of ultramicroscopic viruses. Lancet, December 4th, 1915. 



II.-THE BACTERIOPHAGE: THE BREAKING DOWN 

 OF BACTERIA BY ASSOCIATED FILTER- 

 PASSING LYSINS. 



By F. W. TwoRT, M.R.C.S., L R.C.P. 



( From the Laboratories of the Brown Institution, London. ) 



This phenomenon of bacteriolysis, which in France has been called the "bac- 

 teriophage," consists, as you know, of a breaking down and dissolving up of 

 bacteria by a filter-passing material which in certain circumstances may be 

 associated with pure cultures. My first experiments were carried out at the 

 Brown Institution during 1914 and 1915, for the Local Government Board, and 

 the results were published in the Lancet (December 4th, 1915) under the 

 title of "An investigation on the nature of ultramicroscopic viruses." The con- 

 dition, in my opinion, is distinct from the various degenerative changes which 

 have been so often described in bacterial cultures, and it will be necessary 

 for me to consider in detail experiments on degenerative changes. It is also 

 impossible in the time at my disposal to discuss every aspect of the subject; 

 moreover, other speakers will no doubt deal with the many interesting experi- 

 ments which they have carried out. In this paper I propose to give you as 

 shortly as possible my original experiments as they were published in 1915, 

 and I shall pass on to consider certain aspects of the subject which have since 

 become points of controversy between different workers, and shall then deal 

 shortly with certain more recent experiments which I have been doing on 

 the biology of bacteria, as these may throw some light on the use of the lytic 

 material. 



When starting the research my object was to discover, if possible, the na- 

 ture and life-history of the ultramicroscopic group of viruses. The experiments 

 were carried out with these views in my mind: In the first place we do not 

 know for certain the nature of an ultramicroscopic virus. It may be a minute 

 bacterium that will grow only on living material, or it may be a tiny amoeba 

 which, like ordinary amoebae, thrives on living bacteria or animal tissue. On 

 the other hand, it must be remembered that if the living organic world has 



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