224 SCIENCE PROGRESS. 



titatively, according to strictest chemical canons. But in 

 addition to these there are others, the occurrence of which is 

 very probable, but which are not found in sufficient amount 

 to enable their identity to be irrefragably established. Thus, 

 tyrosine is most probably present in Vicia sativa and Liipinus 

 luteus (etiolated) ; amido-valerianic acid in Lupinus alba 

 (etiolated and chlorophyllous) and Soja kispida (etiolated) ; 

 phenyl-amido-propionic acid in Lupinus alba (chlorophyl- 

 lous), Soja kispida and Lupinus angustifolius (etiolated) ; 

 also leucine and arginin (or similar base) in etiolated Soja 

 kispida. 



The quantitative relations existing between these com- 

 pounds will be discussed below, but it may be advisable to 

 mention that glutamin replaces asparagin in certain plants, 1 

 whereas asparagin replaces glutamin in others, 2 also that 

 in three of these glutamin and asparagin occur together. 13 

 These plants contain also in small amount some of the 

 amido-acids, tyrosine, phenyl-amido-propionic acid, amido- 

 valerianic acid and leucine. 



That these compounds result from chemolysis of the re- 

 serve-proteins is certain. For, it has been quantitatively 

 established that their formation is correlated with loss of 

 proteins, and that the N -content of amido-compounds and 

 proteins are at any given period complementary. Further, 

 it has been satisfactorily shown that, although in some cases 

 very small amounts of amido-compounds, nitrogenous al- 

 kaloids, and other nitrogenous bodies of unknown nature, 

 occur in those seeds from which seedlings have been reared, 

 the amount of these is wholly insufficient to yield even a 

 small fraction of the substances in question. Again, the 

 preparation of extracts and isolation of the compounds has 

 been so undertaken, that their origin could not be accounted 



1 Ricinus communis. Sinapis alba. Brassica Napus, var. annua. 

 Lepidiiwi sativum. Raphanits sativa, var. radicola. Camelina sativa. 

 Spergula arvensis. Spinacia glabra. 



2 Triticum vulgare. Zea Mays. Lolium pratense. Arrhenaterum 

 elatius. Phleum pratense. Papaver somniferum. Tropaeolum majus. 

 Pinus sylvestris. Picea excelsa. Helianthus annum. Cucurbita Pepo. 



3 Helianthus annuus. Cucurbita Pepo. Picea excelsa. 



