CAN OLD LEAVES OF PLANTS PRODUCE ASPARAGINIC 46 1 



only the above analysis but also the following placed beyond 

 doubt. 



Old leaves of The a cliiiiciisis, were analysed again both in 

 the fresh and in the starved condition. Small branches were 

 kept in water from the 23rd May to the 8th June at 19 — 23° C. in 

 a covered vessel in darkness. 



The analytical results were as follows : — 



Fresh leaves. Starved leaves. 



Total nitrogen, 2.575% 3.187% 



Protein nitrogen. 2.149% 2 - l 79% 



Theine nitrogen. 0.288% 0.438% 



Amido-nitrogen. 0.139% °-S7°% 



The relative increase of total nitrogen from 2.575% to 3.187% 

 indicated that 19.21% carbohydrate, fat, and perhaps some carbon 

 and hydrogen from the decomposed proteids, had been consumed 

 by respiration. 



A correct judgement can, of course, be obtained only when 

 the amount of theine-nitrogen in both cases is compared with that 

 of total nitrogen, which we may assume as a constant quantity in 

 both cases ; thus we obtain for 100 parts of total nitrogen 1 1. 15 of 

 theine-nitrogen in the fresh leaves, and 13.74 in the starved leaves. 

 Assuming that no loss of carbon and hydrogen by respiration had 

 taken place, we obtain for the same amount of leaf-weight, i.e., 

 for 0.996 gram, of theine in the original leaf, 1.227 grams of theine 

 in the starved leaf, showing that no consumption of theine had 

 taken place by starvation ; on the contrary an increase is evident. 



This result, compared with the observation on fungi above 

 mentioned, makes it highly probable that theine cannot be con- 

 sidered as a valuable nutrient. (1) It remains now to be seen, 

 whether in presence of much carbhydrate and absence of any other 

 suitable source of nitrogen, theine (caffeine) can be used as a 

 source of nitrogen for building up proteids in tea leaves. 



Analytical Data. 

 In the following analyses, the total nitrogen was determined 

 by Kjeldahl 's method, the protein nitrogen by that of Stutzer, 

 and the asparagine by that of Sachsse, while theine by that of 

 Mulder. 



(i) This inference agrees with the observations of Errcra, Maistriau, and Clan- 

 triau on the behaviour of alkaloid-; during germination (Hull. S'oc. Beige de Microscopi'e, 

 1 894). 



