Some Prospective Problems in Animal Virology

virology may take in the future, I am acutely aware that the unexpected will often happen to turn, to smaller or greater degree, the courses of present investigation which now appear so clearly set. All, or most all, of my conjectures, therefore, may well return to plague me and to show once again the vanity of prophesying. As a further precaution in warding off the stigma of false prophecy, I shall limit myself largely to the mammalian viruses, since here alone have I any competence. Moreover, within this group I shall comment on only a few problems relating to viral replication, pathogenicity including oncogenicity, specific therapy, and vaccination. The large and ever-increasing volume of published experimental work on viral replication strikingly reveals the central position of this phenomenon in contemporary virological research. There are good reasons, both biological and practical, underlying this intensive effort to understand, in detail, how a virus particle, without energy transforming apparatus of its own, manages to utilize the metabolic equipment of the cell to reproduce itself. At present, the specialists in this subject conceive of replication as mediated essentially by viral nucleic acids which assume the role of the