Plant Qrowth'Suhstances 



Creatine and creatinine, already mentioned on p. 50, are 

 important and constant constituents of urine. They can 

 almost certainly supply nitrogen to plants, at least after they 

 have undergone bacterial decomposition. It is not known 

 whether they can act as accessory growth-substances. 



For much of the information given in this section, the 

 author has relied upon the textbooks of biochemistry of 

 H. H. Mitchell and T. S. Hamilton ("The Biochemistry of 

 the Amino Acids": Chemical Catalog Co., New York, 1929, 

 and of B. Harrow and C. P. Sherwin ("A Textbook of 

 Biochemistry": W. B. Saunders Co., Philadelphia, 1935), 

 and particularly in the latter the section on detoxication by 

 A. M. Ambrose and C. P. Sherwin. See also the sections: 

 "Nachweis und Bestimmung von Abkommlingen des Trypto- 

 phans im Ham", by W. Weise, in Abderhalden's Handbuch, 

 193 1, Abt. 4, Teil. 5(1), 765-784, and "Von Tryptophan 

 ableitbare biochemisch wichtige Verbindungen," by A. 

 Ellinger in the same Handbuch, Abt. i, Teil 7, 779-806, 

 especially for E. and H. Salkowski's method of preparation 

 from decomposed protein material. 



To these and to similar sources the reader is referred for 

 references and more details. 



76 



