6o 
THE FORMATION OF PROTEIDS IN PLANT-CELLS. 
the presence of a digesting ferment, resembling trypsin, in plants, 
to which he ascribed the production of amido-acids from proteids. 
If we compare now the quantities of the different amido- 
acids and bases with that of asparagin we find generally the 
latter present in larger quantity, although the decomposition of 
proteids by enzymes or by mineral acids yields only relatively small 
quantities of aspartic acid (which in the plant-cells might easily 
be transformed into asparagin). While ioo parts of conglutin 
(the principal reserve protein in lupins) yield upon decomposition 
with hydrochloric acid 6 parts of glutaminic acid, 1,5 parts of 
aspartic acid, 10 parts of leucin and 2 parts of tyrosin, we find in 
lupin-shoots 12 days old, the asparagin in dominating quantities, 
amounting to almost 30 per cent of the dry substance, while 
tyrosin was found only in traces and glutamin could not be found 
with certainty. Instead of leucin the next lower homologue 
(perhaps produced from the former by oxidation), was found. 8) 
The germinating seeds of Cucurbita contain only a very small 
amount of leucin, but 1,75 per cent of glutamin and 0,06 per cent 
of asparagin ; tyrosin amounted here to 0,25 per cent. 
According to Ritthausen gluten-casein yields on decompo¬ 
sition with hydrochloric acid 0,3% aspartic and 5,3% glutaminic 
acid; legumiri yields 3,5% of the former and 1,5 % of the latter 
(only mucedin yields larger quantities of glutaminic acid, 
viz. 25%). Still we find in plants generally asparagin as 
the main product, 1 2 3) 4 the other amido-compounds disappearing 
rapidly again and being found only in relatively small quantities. 
Schulze supposed that the decomposition of protein in plants 
would yield the same products and in the same quantities as 
the decomposition by trypsin or by acids, but that the rege¬ 
neration of proteids would proceed more easily from the 
other amido-compounds than from aspartic acid, hence the 
latter—transformed into asparagin—must accumulate. 4 ) This is, 
1) Ber. Deutsch. Chem. Ges. Vol. 7 and 10. 
2) E. Schulze and Barbiéri , Landw. Jahrb. 1880, p. 18. Most proteids yield by 
decomposition with acids more than 20 per cent leucin . 
3) In certain cases mentioned above, asparagin is found replaced by its next 
homologue, glutamin. This might he gradually transformed into the former in the 
plant-cells or like asparagin serve in the regeneration of certain proteids. 
4) Other views upon this subject were discussed by E. Schulze in Landw. Jahrb. 
Vol. 17 and 21.—He showed that they are either incorrect or imperfect. 
