812 THE ROLE OF NITROGEN, ETC., I., 



Concerning the nitrogenous reserves of plants> the most 

 important chemical researches have been done on seeds. In these 

 we find the substances more permanent and definite, while in 

 other parts of the plant the various compounds are constantly 

 changing, though they try to retain equilibrium between the 

 anabolic and katabolic processes. 



The Nitrogen Compounds in Seeds. — The nitrogenous material 

 in seeds may be considered first as proteins and non-protein 

 compounds. The Proteins are classed as follows : — 



1. Phyto-albumins — soluble in water. 



2. Phyto-globulins — soluble in salt sols., insol. in 1. 



3. Phyto-gliadins — soluble in alcohol, insol. in 1 and 2. 



4. Phyto-glutelins — sol. in dil. acids or alkalies, insol. in 1, 2, 3. 



5. Conjugated proteins — nucleo-proteins,lecitho-proteins(though 

 it is not yet known whether these are true chemical compounds,, 

 adsorbed substances, or aggregates), toxalbumins, etc. 



6. Proximate cleavage-products — proteoses and peptones. 

 The non-protein nitrogen compounds are : — 



1. Amides — glutamin and asparagin, and probably others. 



2. Amino-acids. 



3. Diamino-acids or the hexone-bases— histidin, arginin, lysin. 



4. Nucleic acid and Purins — vernin and the purin bases 

 guanidin, adenin, guanin, hypoxanthin, xanthin, allantoin. 



5. Lecithin and its decomposition-products — cholin, betain r 

 amines, trimethylamine. 



6. Alkaloids. 



7. Glucosides and their decomposition-products, including 

 hydrocyanic acid. 



1. Our knowledge of the vegetable proteins has been greatly 

 enhanced in recent years by the researches of Osborne and his 

 co-workers in America. The various proteins in the seeds of most 

 of the cereals, in a number of legumes and nuts, have been 

 separated and examined. From wheat, Osborne and Voorhees(36) 



