Prolycopene, a Naturally Occuring Stereoisomer of Lycopene.

-Spores of the fungi Rhizopus suinus, Mucor dispersus and Aspergillus melleus were tested with respect to their resistance to ultraviolet of wave-length 2650 A. Sigmoid survival curves were obtained for the fungi Rhizopus suinus and the minus strain of Mucor dispersus when spores from 4-day cultures were irradiated. Survival curves describing a logarithmic order of death were exhibited by spores from 4-day cultures of Aspergillus melkeus. The three species of fungi showed marked differences in susceptibility to radiation (2650 A). A combination of the differences in pigmentation, size of the spores and the number of nuclei may account for the differences in susceptibility observed. A trend of increasing resistance to radiation with increased age was observed for spores of Rhizopus suinus. ' Smith, E. C., in Biol. Effects of Radiation, 2, 889-918 (1936). 2 Smith, E. C., Bull. Torrey Bot. Club, 62, 45-58, 151-164 (1935). 3 Oster, R., Jour. Gen. Physiol., 18, 71-88, 243-250, 251-254 (1934). 4Hollaender, A., and Emmons, C. W., Jour. Cell. and Comp. Physiol., 13, 391-402 (1939). 6 Landen, E. W., Ibid., 14, 217-226 (1939). 8 Luyet, B. J., Radiology, 18, 1019-1022 (1932). 7Schreiber, H., Strahlentherapie, 49, 541-595 (1934). 8 Duggar, B. M., and Hollaender, A., Jour. Bact., 27, 219-239, 241-256 (1934). 9 Thom, C., and Church, M. B., The Aspergilli (1926). 10 Nielsen, N., Virchow's Arch. f. path. Anat. u. Physiol., 273, 859-863 (1929). 11 Saccardo, P. A., Sylloge Fungorum, 21, 821 (1912). 12 Zahl, P. A., Koller, L. R., and Haskins, C. P., Jour. Gen. Physiol., 22, 689-698 (1939).