J 74 



PHYSIOLOGY OF NUTRITION 



teins. Ivanov 1 determined the amounts of phosphorus of various kinds of 

 compounds, in seeds and etiolated seedlings of Vicia faba, and obtained the 

 results given in the table below, where the numbers are percentages, on the basis 

 of total phosphorus content. 



Seeds 



Seedlings 

 5 Days Old 



Phosphorus of inorganic phosphates 11.4 



Phosphorus of lecithin 11. 6 



Phosphorus of proteins 52.5 



Phosphorus of organic phosphates 25 . 7 



48.1 



37-4 

 9.8 



Seedlings 

 20 Days Old 



80.2 



6.6 

 13 -7 



5-i 



Germination in darkness thus appears to be correlated with a pronounced 

 decomposition of phosphorus-containing proteins. In resting seeds protein 

 phosphorus amounted to 52.5 per cent, of the total phosphorus content, while 

 seedlings twenty days old contained protein phosphorus amounting to only 

 13.7 per cent.; in the latter case most of the phosphorus occurred as inorganic 

 phosphates. 2 Zaliesskii 3 obtained results similar to these. He found, for ex- 

 ample, that the phosphorus-containing proteins disappear from the cotyledons 

 of germinating seeds, while the amount of these proteins increases markedly 

 in the axial organs, since growth is accompanied by synthetic processes. 

 Thus, in the axial parts of Vicia faba seedlings three days old, the ratio of 

 protein phosphorus to protein nitrogen was found to be 0.0125:0.0850(1:6.8), 

 while the corresponding ratio for seedlings nine days old was 0.0337:0.3755 

 (1:11.1). 



The researches of Burkevich, Zaliesskii, 4 Ivanov, 5 Kovshov 6 and Gromow 7 

 show that the cleavage of phosphorus-containing as well as that of phosphorus- 

 free nitrogens is dependent upon enzymatic processes. 



1 Ivanow, Leonid, Ueber die Umwandlungen des Phosphors beim Keimen der Wicke. (Vorlaufige 

 Mittheilung.) Ber. Deutsch. Bot. Ges. 20: 366-372. 1902. Idem, Ueber die Umwandlungen des Phos- 

 phors in der Pflanze im Zusammenhange mit der Eiweissstoffmetamorphose. Arbeit. Naturforscherges. 

 St. Petersburg 34: 1-170. 1905. [Russian.] [Rev. in: Bot. Centralbl. 103: 83. 1906.] 



2 Vorbrodt, Wlad., Untersuchungen uber die Phosphorverbindungen in den Pflanzensamen, mit be- 

 sonderer Berucksichtigung des Phytins. [Title also in Russian. Text in German.] Bull, internat. 

 (classe sci. math, et nat., ser A.) Acad. Sci. Cracovie 1910: 414-511. 1910. 



s Zaelski, W., Beitrage zur Verwandlung des Eiweissphosphors in den Pflanzen. Ber. Deutsch. Bot. 

 Ges. 20: 426 — 433. 1922. Idem, Ueber den Umsatz der Nucleinsaure in keimenden Samen. Ibid., 25: 

 349-356. 1907. 



4 Zaleski, W., Beitrage zur Kenntnis der Eiweissbildung in reifenden Samen. (Vorlaufige Mitteilung.) 

 Ber. Deutsch. Bot. Ges. 23: 126-133. 1905. Idem, Zur Kenntnis der proteolytischen Enzyme der rei- 

 fenden Samen. Ibid. 23: 133-142. 1905. Idem, Ueber den Umsatz der Phosphorverbindungen in 

 reifenden Samen. Ibid. 25: 58-66. 1907. Idem, Ueber die autolytische Ammoniakbildung in den Pflan- 

 zen. Ibid. 25:357-360. 1907. Idem, 1907. [See note 3, this page.] 



5 Ivanov, 1902, 1905. [See note 1, this page.] 



6 Kovshov, I. D., Fermentative Eisweisszersetzung in erfrorenen Pflanzen. [Russian, with German 

 abstract.] Trav. Soc. Imp. Nat. St.-Petersbourg 35 s (Jour. bot. 1) : 180-185. 1906. [German abstract, 

 p. 187.] 



7 Gromow, T., and Grigoriew, O., Die Arbeit der Zymase und der Endotryptase in den abgetoteten 

 Hefezellen unter verschiedenen Verhaltnissen. Zeitsch. physiol. Chem. 42: 299-329. 1904. 



