178 Journal of Agricultural Research voi.iu.No.ai 



Hypoxanthin Adcniii 



(6 oxypurin) (6 amino-purin) 



NH-CO N=C.NHj 



II II 



CH C-NH. CH C-NH. 



II II ^CH II II \CH 



N - C- N *^ N-C- N '^ 



Guanin ■ 



(6 ammo-6 oxypurin) 



NH-CO 



I I 

 NH2.C C-NHv 



II II JCH 

 N - C- N*^ 



Xanthin, hypoxanthin (Schreiner and Shorey, 1910), and adenin 

 (Shorey, 1913b, p. 16) have been found in soils, and guanin has been 

 found in a soil that had been heated (Lathrop, 1912). All four bases 

 have been found in plants and may also be formed from nucleic acid, 

 a constituent of all nucleated cells of both plants and animals. 



LITERATURE CITED 

 Lathrop, E. C. 



igi2. Guanine from a heated soil. In Jour. Amer. Chera. Soc., v. 34, no. 9, 

 p. 1260-1263. 

 ScHiTiENHELM, ALFRED, and Wiener, Karl. 



1909. Carbonyldiharnstoff als Oxydationsprodukt der Hamsaure. In Ztschr. 



Physiol. Chem., Bd. 62, Heft i. p. ioo-io6. 



SCHOLTZ, M. 



1901. Ueber ein neues Oxidationsproduct der Harnsaure. In Ber. Deut. Chem. 

 Gesell., Jahrg. 34, Bd. 3, No. 17, p. 4130-4132. 

 Schreiner, Oswald, and Shorey, E. C. 



1910. Pyrimidine derivatives and purine bases in soils. In Jour. Biol. Chem., 



V. 8, no. 5, p. 385-393. 

 Shorey, E. C. 



1913a. Recent work on the chemical composition of humus. (Abstract.) In 



Jour. Wash. Acad. Sci., v. 3, no. 9, p. 260. 

 1913b. Some organic soil constituents. U. S. Dept. Agr., Bur. Soils Bui. 88, 



41 P-. I pl. 

 1914. The presence of some benzene derivatives in soils. In Jour. Agr. Research, 

 V. I, no. 5. P- 357-363. 



