Microbial Genetics ed. by W. Hayes and R. C. Clowes (review)

he generalizes the formula, he presents a form due to Haldane (1950) but unfortunately omits a bracket; i.e., formula (2b) should read h = ^i±üí} 16 (j +F)""' where F is the coefficient ofinbreeding. The examples ofthe use ofthis formula in the last column of Table 55 are quite unrealistic for human populations. On page 389 Dahlberg 's formula for calculatingthe size of genetic isolates from the frequencyof consanguineous marriages is given. The basic assumption "that consanguinity is as frequent as required by random mating" is stated, but with no discussion ofhow far social customs result in departures from this assumption and the severe limitations thus placed on the use of the formula. By contrast, chapters 20 and 21 on sex determination and the sex ratio constitute an outstanding review ofthis entire topic. Chapter 24, on the genetic hazards ofradiation, is a notably balanced treatment ofa controversial topic, detailing the many uncertainties that enter into quantitative treatments ofthe subject and the problem for society involved in striking a balance between the undoubted harmful genetic effects ofradiation and the benefits that sources ofradiation in various forms hold for mankind. Finally, chapter 28, on selection and genetic polymorphisms, draws attention to the increasing recognition of the possible importance for human genetics of polymorphic systems such as that responsible for the ABO blood groups. The format of the book is clear and attractive. The illustrations are excellent, a distinct improvement over those in the first edition. All in all, Dr. Stern's is a truly outstanding text; its primacy is not apt to be challenged for some time. James V. Neel University ofMichigan Microbial Genetics. Edited by W. Hayes and R. C. Clowes. Society for General Microbiology Tenth Symposium, April, i960. New York: Cambridge University Press. Pp. 300. $7.50. The tenth symposium, judged by this volume, was ten to four in favor of bacteria as the material for study under the general heading "Microbial Genetics." Among the articles dealing with bacteria there are, in addition to the general introduction by Stocker, papers on the bacterial chromosome (Hayes); the bacterial nucleus (Kellenberger); bacterialepisomes (Jacob, Schaeffer, and Wollman); the biologicalfunctionofDNA (Ephrussi -Taylor); DNA and specific protein synthesis (Brown); and nucleic acids and bacterial growth (Maal0e). The fine structure ofbacterial genetic material is considered by Clowes (genetic analysis by transduction), E. Lederberg (galactose mutants ofEscherichia coli), and Garen (alkaline phosphatase gene). Non-bacterial matters include recombinational analysis in Aspergillus and its significance for other organisms (Pritchard); the relation of genotype to enzyme content (Catcheside); RNA as viral genetic material (Gierer); and a brief summary of nuclear 382 Book Reviews Perspectives in Biology and Medicine · Spring 1961 transfer studies in Amoeba (Danielli). All the articles are worth reading, some are stimulating , and the volume is, in general, recommended. Variation among the authors' precision in writing is notable. One can wonder about the value ofreferring to "transduced characters" and "transduced clones," as one author does (and in the same sentence). The considerations by Pritchard ofrecombinational analysis are probably the most analytical in the volume; he reports interesting observations which support the hypothesis that homologous contact between chromosomes is a limiting factor in recombination. For the person with a general interest in genetics, this volume will be a helpful up-to-date summary, and for the specialist in this area, necessary reading. M. L. Morse University ofColorado Attenuated fofection: The Germ Theory in Contemporary Perspective. By HaroldJ. Simon. Philadelphia: Lippincott & Co., i960. Pp. xvi + 349. $10.00. The period 1950-60 witnessed a revival and extension ofthe perspectives to infectious disease which were earlier promulgated by Charles Nicolle and Karl F. Meyer. The concept ofinfection without disease as a particular phase of a host-parasite relationship has been widely attended by virtue ofthe variety ofstudies directed toward a better understanding ofnatural resistance. It was inevitable that a new surge ofinterest would follow the many observatons that cells ofpresumably healthy hosts harbored infective agents, whether these agents be bacteriophages, plant or animal viruses, or bacterial or protozoan forms. Activation of silent infections—or as Simon prefers to term them, "attenuated infections"—by hormones, drug therapies, irradiation, or a host ofodier activating procedures ^—has fostered the view that die state ofinfection...