Pyrimidine Moieties in Animals, Plants, and Bacteria 119 



63. Sibatani, A., Yamana, K., Kimura, K., and Takahashi, T.: Frac- 



tionation of two metal^olically distinct classes of ribonucleic acids 

 in animal cells and its l:)earing on cancer. Nature, 786:215-217, 1960. 



64. Simon, E. H.: Evidence for the nonparticipation of DNA in viral 



RNA synthesis. Virology, 7J.- 105-1 18, 1961. 



65. Sinsheimer, R. L.: A single stranded deoxyribonucleic acid from 



bacteriophage 0X174. J. Molec. Biol., 7.-43-53, 1959. 



66. Sinsheimer, R. L.: The Nucleic Acids of the Bacterial Viruses. The 



Nucleic Acids III, ed. by E. ChargafF and J. N. Davidson, New 

 York, Academic Press Inc., 1960, p. 187. 



67. Speyer, J. F., Lengyel, P., Basilio, C. and Ochoa, S.: Synthetic 



polynucleotides and the amino acid code. II. Proc. Nat Acad. Sci. 

 USA, 48:63-68, 1962. 



68. Spiegelman, S., Hall, B. D. and Storck, R.: The occurrence of 



natural DNA-RNA complexes in E. coli infected with T2. Proc. 

 Nat. Acad. Sci. USA, 47; 11 35-1 141, 1961. 



69. Spirin, A. S.: The "temperature effect" and macromolecular struc- 



ture of high-polymer ribonucleic acids of various origin. Bio- 

 chemistry (USSR), 2(5.-454-463, 1961. 



70. Stephenson, M. L. and Zamecnik, P. C: Purification of valine 



transfer ribonucleic acid by combined chromatographic and chem- 

 ical procedures. Proc. Nat. Acad. Sci. USA, 47.- 1627-1 635, 1961. 



71. Stevens, A.: Net formation of polyribonucleotides with base com- 



positions analogous to deoxyribonucleic acid. J. Biol. Chem., 236 

 PC43-45 (July) 1961. 



72. Sueoka, N.: Variation and heterogeneity of base composition of 



deoxyribonucleic acids: A compilation of old and new data. J. 

 Molec. Biol., J.- 3 1-40, 1961. 



73. Tessman, I.: Mutagenesis in Phage 0X174 and T4 and properties 



of the genetic material. Virology, 9.-375-385, 1959. 



74. Thomas, R. S.: The chemical composition and particle weight of 



tipula iridescent virus. Virology, 74.-240-252, 1961. 



75. Vendrely, R.: The Deoxyribonucleic Acid Content of the Nucleus. 



The Nucleic Acids II, ed. by E. Chargaff and J. N. Davidson, New 

 York, Academic Press, Inc., 1955, p. 155. 



76. Volkin, E. and Astrachan, L.: RNA Metabolism in T-2 Infected 



Escherichia coli. The Chemical Basis of Heredity, Baltimore, The 

 Johns Hopkins Press, 1957, p. 686. 



77. Watson, J. D. and Crick, F. H. C: The Structure of DNA. Cold 



Spring Harbor Symposium on Qjiantitive Biology, /5'."123-131, 1953. 



