On the Formation of Proteids and the Assimilation 

 of Nitrates by Phaenogams in the 

 Absence of Light. 



BY 



TJ. Suzuki, Nogakitshi. 



The question whether nitrates can be assimilated and proteids 

 can be produced by Phaenogams in the dark, still meets with con- 

 tradictory answers, KiiiosJiita concluded that nitrates can thus 

 give rise to some asparagine. He experimented with young 

 barley plants 20 cm. high, and found that ammonium salts yield 

 much more asparagine than nitrates.'^- From experiments with 

 Leuiiia, Hattsteen inferred that ammonium salts are more easily 

 assimilated in darkness, when some cane sugar is present, nitrates 

 however but little/"' Isliizuka observed that nitrates stored up in 

 the roots of BatatJis cdiilis, Nelitnibo niicifera, Lilunii tigrinnm, 

 Helianthns tiiberosus. Capsicum longitm, Eiitrcma zvasabi, Colocnsia 

 antiqiioriim, tubers of Solaiuun tuberosiiDi, and in the fruits of 

 Cticiirbita pepo, gradually decrease, when kept for several weeks in 

 the dark, while the amount of asparagine increases.'^' In my ex- 

 periments with etiolated shoots of the potato, I also observed the 

 conversion of nitrates into asparagine, when some sugar was present ; 

 but generally ammonium salts and urea were more easily assimilat- 

 ed.'^' Godlezvski concluded from his experiments on wheat that 

 nitrates can be assimilated in darkness, whereby aviido compounds 

 are produced (whose nature he did not investigate) but no Pro- 

 tcidsS^^ Laurent, on the contrary asserts that neither ammonium 

 salts nor nitrates can be assimilated in darkness.'"' I have for some 

 time devoted my attention to this interesting question. My first 



(1) Bulletin of college of Agriculture. Tokyo Vol. II. No. 4. (1895). 



(2) Ber. d. bot. Ges. 14, 368 (1896). 



(3) Bulletin of Coll. of Agriculture. Tokyo. Vol. II. No. 7. 



(4) Bulletin of College of Agriculture. Vol. II. No. 7. 



(5) Auzeiger der Akadeniie der Wisscnscliaften in Krakau. Marz 1897. 



(6) Bull, de I'Akademic royale de Belgique 32. No. 2. (1896). 



