352 



U. SUZUKI. 



for further use. 1 The carbon for the asparagin is furnished 

 either by the products of partial oxidation of the amido-com- 

 pounds or by sugar. 



Now if this view is correct, then the partial destruction of 

 the primary amido-compounds, and hence also the formation of 

 asparagin, would be stopped when air is withheld and oxidation 

 is prevented. I therefore tested the behaviour of shoots in the 

 absence of oxidation, which deprivation they can endure for a 

 certain time. Such an experiment had already been made by 

 Pal/adin, 2 wlio observed that in the absence of oxygen asparagin 

 formation stops, which fact he, however, tried to explain in a 

 manner quite different from that which we can accept. 3 Clausen 

 repeated these experiments with less decisive results. 4 



My experiments, however, with barley and soy bean shoots 

 confirm the observation of Palladin, and I infer therefore that 

 asparagin must be considered as a synthetic product formed 

 zvith the aid of an oxidation process, after partial destruction of 

 the primary amido-compounds. In my experiment, the etiolated 

 shoots were kept in an atomosphere free of oxygen 5 for 45 — 52 

 hours at a temperature of 15 — 20 0 . 



I then compared the amount of ammonia and of asparagin 

 with that of the control plants. In my first experiment with 

 barley I had withheld the oxygen for too long a time and 

 some shoots had died off ; hence this experiment with barley 

 shoots had to be repeated. 



Experiment with barley. 



Etiolated shoots of barley of an average length of 24 cm. 

 were carefully deprived of their endosperm 6 and divided into 

 three portions : 



1 Bull. College cf Agr., Imp. Univ. Tokyo. Vol. II. No. 7. (1897). 



* Ber. D. Bost. Ges., vol. 6. (1888). 



3 He believed that the protein yields asparagin by direct oxydation. 

 « Land \v. Jahrbiicher, Vol. 19. 



6 The oxygen was removed by caustic soda and pyrogallol in the usual way. By 

 measuring the decrease of the volume of the air in the bell jar, the test was made for 

 the complete absorption of the oxygen. 



* The presence of the endosperm would have rendered the result much less decisive. 

 It was to be assumed from analogy that the young plant had absorbed a sufficient 

 amount of the primary amido-compounds, foimed previously in the endosperm from 

 protein, to assure a proper answer to our question. 



