Strauss, Norman (Yale University, New Haven, Conn.). Configuration of transforming deoxyribonucleic acid during entry into Bacillus subtilis. J. Bacteriol. 89:288–293. 1965.—A correlation was obtained between map distance and the length of the lag period preceding the appearance of pairs of genetic traits after the addition of deoxyribonucleic acid (DNA) to a competent culture of Bacillus subtilis. The results are taken to indicate that DNA enters competent cells in lengthwise fashion. The smallest length of transforming DNA which can participate in a recombination event, and the number of nucleotide pairs which enter the cell per unit time, have been estimated. The evidence indicates that only part of the lag period is devoted to the transport of DNA into the cell. The significance of these results with respect to the mechanism of entry of DNA into the cell is discussed.