Plant Qrowth'Suhstances 



ing snag for the unwarned non-biologist. Tap water (if not 

 chlorinated) or water from a silver-lined or glass still should 

 be used as diluent. Water from a copper still contains enough 

 copper to ruin many experiments with even intact plants, and 

 these tender pea preparations are very easily hurt. My 

 parting word to my fellow chemist is : Remember in doing any 

 work with plants, that you are handling a structure of wonder- 

 ful complexity, and alive. 



REFERENCES J 



Book 



Plimmer, R. H. A. (1918), Practical Organic and Biochemistry 

 (London). (New edition, 1938.) 



Periodicals 



Albaum, H. G., and Kaiser, S. (1937), Amer. Journ. Bot., 24, 



420. 

 Baumann, E. (1882), Ztschr. physiol. Chem., 6, 191. 

 Baumann, E. (1891), ibid., 16, 268. 

 Ellinger, A., and Flamand, C. (1909), Ztschr. physiol. Chem., 



62, 276. 

 Fischer, H. (1923), Ber., 56, 2313. 

 Foiling, A. (1934), Ztschr. physiol. Chem.y 227, 169. 

 Gstirner, F. (1939), Pharm. Zentralhalle, 80, 1-5, 22-27, 



34-38 (from Chem. Abs., 33, 2928). 

 Herter, C. A. (1908), Journ. Biol. Chem., 4, 253. 

 Kogl, F., Haagen-Smit, A. J., and Erxleben, Hanni (1934), 



Ztschr. physiol. Chem., 228, 90. 

 Marrack, J., and Hollering, Helga F. (1939). Lancet, I, 325. 

 Mitchell, J. W., and Brunstelter, B. C. (1939). Bot. Gaz., 



100, 802. 

 Penrose, L., and Quastel, J. H. (1937), Biochem. Journ. y 31, 



266. 

 Riesser, O. (191 1), Zur Chemie des Uroroseins. Inaug. 



134 



