730 EXPERIMENT STATION RECORD. 



contains, besides a brief notice of other contributions, a summary of the progress 

 made by bim to date, in substance as follows : 



Without expecting to arrive at an immediate explanation of the progress of 

 protein synthesis in plants, the investigator aimed at the collection of more ob- 

 servation material upon which possibly to base a theory of such process. In the 

 first comnninication on this subject attention was called to the fact that for 

 answering the question as to which nitrogen compounds serve chiefly in ripen- 

 ing seed as material for protein synthesis, the conclusions reached by investiga- 

 tions of such seed are in themselves of no great importance. It is reasonably 

 certain that for this rapidly advancing process many nitrogen compounds move 

 rapidly from elsewhere in the plant, while others move slowly or not at all, so 

 that the rest of such compounds which are found in unripe seeds along with the 

 protein may vary widely from the mass of nitrogen comiX)unds which go to these 

 seeds out of other parts of the plant. This mass was investigated, and it is 

 claimed that information was gained not only on the seed hulls as receptacles 

 for reserve materials, but also on leaves and stems as such receptacles in the 

 case of young legumes. It appears that of these, asparagin is present in quan- 

 tities greater than that of any other nonproteid nitrogen compound. The unripe 

 seeds contain amids in very small amounts only. Seeds of Phaseoliis vulgaris 

 tested for asparagin gave negative results. This is in keeping with the view 

 that in the ripening seeds asparagin is employed in pi'otein building. This amid 

 probably finds like employment in the young leaves. 



Doubtless in the case of the legumes the mixture of nonproteid nitrogen com- 

 pounds that travel toward the ripening seeds have a great similarity with that 

 which goes to the young leaves of the rest of the plant. This points to the con- 

 clusion that in the ripening seed the protein synthesis goes on much as in the 

 young leaves, but the manner of this process is unknown at present. 



In unripe legume seeds there are found along with proteins small quantities 

 of asparagin, monoamiuo acids, arginin, histidiu, etc. This is easily explainable, 

 for it may be accepted that the building of protein out of nitrogenous material 

 from the hulls as well as from leaves and stems requires a certain time, and is 

 complete only with the full ripening of the seeds. If unripe seeds were ex- 

 amined at any stage tliere would be found along with proteins other uiti'ogen 

 compounds. By comparing these with the mass of nonproteid nitrogen com- 

 pounds going to the seeds, it was found that only in unripe seed hulls, not in the 

 vmripe seeds, was tryptophan to be found. This is comprehensible on the view 

 that the tryptophan is transferred from the hulls into the ripening seeds, there 

 to be employed in protein synthesis, and in consequence is not present in appreci- 

 able quantities. 



On the other hand, it was found that the unripe seeds contain some glutamin, 

 while this amid was not yet to be found in the seed hulls nor in the leaves and 

 stems. This may be explainable on the supposition tliat minute quantities of 

 glutamin, along with asparagin, migrate toward the ripening seeds to the end of 

 protein synthesis, and that being more slowly changed than asparagin the 

 glutamin accumulates there in sufficient quantities to respond to test. That 

 one can in like manner account for the great difference as regards arginin con- 

 tent which shows itself between the unripe seeds and the rest of the plant must 

 be considered questionable. It seems that one must here also think of a 

 synthetic manufacture of arginin in the ripening seeds. 



The author claims that the question left open by A. Emmerling as to which 

 particular materials migrate to the ripening seed from the rest of the plant 

 may be partially answered, since in the case of the legumes not only out of the 

 reserve-holding seed hulls but also out of the leaves and stems a number of 



