42 Literatlire on Inosite-Phosphoric Acid [Sept. 



In the earlier analyses of seeds, the inorganic phosphorus was not 

 given a very prominent place and was usually reported as that por- 

 tion obtained by subtracting the sum of the protein and lecithin phos- 

 phorus from the total phosphorus; but as this dement began to re- 

 ceive special attention its direct determination was attempted, and 

 consequently the amount of inorganic phosphorus reported was 

 lessened. Thus Umikoff^^ estimates the inorganic portion as fully 

 half of the total phosphorus, but the more recent workers report 

 it in very small percentages. With the germination of the seed, 

 the inorganic phosphorus gradually increases at the expense of the 

 organic form. This was at first attributed to the breaking up of the 

 phosphorus-bearing proteins and lecithins. Tammann,^'' one of the 

 earliest investigators to make direct determinations of inorganic 

 phosphorus in seeds and their sprouts, found during germination 

 an increase of this form which, in terms of P2O5, was from 0.324 

 per Cent, to 0.443 P^^ cent. in a period of only twelve days. Ac- 

 cording to the work of Prianischnikow^^ and Merlis,^^ lecithin de- 

 creased one half during fifteen days' germination of Vicia sativa 

 and Lupinus angustifolius. Iwanow found that the inorganic phos- 

 phorus increased from a very small amount to 93.7 per cent. of the 

 total phosphorus in germinating seeds of Vicia faba. He held 

 that lecithin is the most stable of the organic forms and is altered 

 very little. Phytin, owing to the presence of phytase, is practically 

 all changed by this process. 



Vorbrodt has shown that the phosphorus Compounds, especially 

 inosite-phosphoric acid, are particularly abundant in the germ. 

 When the seed begins to sprout, this supply is increased by trans- 

 portation of phosphorus from other parts of the grain, as is indi- 

 cated by Zalesky's^^ Observation that in the sprouts of Lupinus 

 angustifolius the total phosphorus increased in twenty-five days 

 from 0.302 gram to 0.514 gram; the inorganic phosphorus doubled 

 in amount, while the protein and lecithin phosphorus remained prac- 



"Umikoff: Russian Dissertation, 1895. (Cited by Zalesky: Ber. bot. Ges., 

 1902, 20, 426-433.) 



^Tammann: Zeit, für physiol. Chem., 1885, 9, 416-418. 



" Prianischnikow, 1895. (Cited by Zalesky. See footnote 19.) 



^'Merlis: Landw. Vers. Stat., 1897, 18. (Cited by Zalesky. See footnote 19.) 



^Zalesky: Ber. bot. Ges., 1902, 20, 426-433. 



