Croonian Lecture.―The theories of the bacteriophage

Abstract

Allow me, in the first place, to tell you what pleasure I experienced when the Royal society, now many years ago, elected me to its Foreign Membership, and how deeply I feel to-day the honour of having been chosen to give to the society the Croonian Lecture tor this year. The phenomenon of the destruction of microbes known under the name of “bacteriophagy,” or transmissible autolysis, quickly aroused the liveliest interest, firstly, because its importance was foreseen, and secondly, and perhaps to a greater decree, by reason of its character, so bizarre and so unexpected. Is it not, indeed, surprising to find that a bacterial culture, grown on the surface of an agar medium, becomes sprinkled with holes, in the neighbourhood of which the culture is deeply corroded? Is it not, further, remarkable to find that a broth, to which has been added the active principle responsible for this effect, is thereby rendered unsuitable as a medium for culture, or that, under the action of the same principle, a turbid microbial suspension, obtained by emulsifying the culture from a solid medium, becomes clear ? Is it not even more remarkable that the active principle regenerates itself in producing its effect, and can accordingly he reproduced indefinitely ?