CAN OLD LEAVES OF PLANTS PRODUCE ASPARAGINE. 461 
only the above analysis but also the following placed beyond 
doubt. 
Old leaves of Thea chine 11 sis, 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 * I 79 % 
Theine nitrogen. 0.288% 0.438% 
Amido-nitrogen. °- I 39 % 0.5 7 °% 
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 11.15 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 KjeldahVs 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 Errera , Maislriau , and Ctau- 
triau on the behaviour of alkaloids during germination (Pull. Soc. Belge de Microscopie, 
1894). 
