BY JAMES M. PETRIE. 817 



1. Amides are apparently not present in the reserve-material 

 of seeds. Schulze and Castoro,(48) working on a kilogram of 

 leguminous seeds, after having separated the proteins and boiled 

 the solution with acid (to decompose amides), could not obtain 

 any reaction with Nessler's solution, and therefore amides could 

 not have been present. The same authors(49) were able, however, 

 to separate a very small amount of asparagin from the embryos 

 of wheat-grains. Acton(50) compared old wheat that had been 

 stored for twenty-eight years with new seeds from the same field, 

 and found no amides in the latter, while the dead seeds contained 

 0-8 %, probably the result of ferment-action at an earlier stage. 



2. Amino-acids are the simple raw material out of which 

 proteins are synthesised, and since the reserve-proteins are 

 formed and secreted in the seeds during their growth it is 

 evident that a transportation of this raw material to the seeds 

 must take place. One would therefore expect to find amino-acids 

 during the early stages of seed-formation, but the few investi- 

 gators who have examined seeds in most cases have obtained 

 negative results. Ritthausen searched in vain for amino acids 

 in those seeds richest in proteins, namely the leguminosse; and 

 Schulze, too, has long sought for the same with a similar result, 

 except that a very small amount of tyrosin was obtained from 

 500 gms. of Lupinus luteus seeds! 51). Tyrosin is the most 

 insoluble of the amino-acids, and has definite colour-reactions, 

 hence is the one most easily detected. These negative results, 

 however, are no proof of the absence of amino-acids, as in the 

 uncrystallisable syrups invariably obtained on evaporating the 

 solutions our imperfect methods scarcely allow of finding small 

 quantities, and the crystallisation is prevented by the large 

 proportion of impurities. 



3. Diamino-acids, mainly arginin, have been recognised in 

 resting seeds by Schulze and Castoro'.5i). From Lupinus luteus 

 they obtained 04% of arginin, and from L. albus 0*02%; the 

 presence of histidin was indicated, but in quantity too small for 

 identification. 



