THE FORMATION OF TROTBIDS IN PLANT-CELLS. 6l 



however, an erroneous assumption, for experiments with bacteria 

 and with mould-fungi have convinced us that asparagin and 

 aspartic acid form most excellent nutrients, being evidently very 

 favorable sources of carbon and nitrogen for the formation of 

 protein, for the growth of protoplasm, i. e. multiplication of 

 cells. These combinations ai - e far superior to tyrosin or phenyl- 

 amidopropionic acid, which would, moreover, have to undergo a 

 thorough chemical change before the formation of proteids 

 could commence. 



An observation of E. Schulze is, in this connection, of fun- 

 damental importance. He found that the quantity of amido- 

 acids formed during the first period of germination is con- 

 tinually decreasing, whilst the amount of asparagin is increasing ; 

 he showed furthermore, that the proportion of asparagin is much 

 greater in the axial organs than in the cotyledons, as is seen 

 from the following table : 





The protein-free extract contains 







nitrogen in form of: 





Lupin shoots. 



In the cotyledons. 



In the axial parts. 





Asparagin. 



Other amido- 

 compounds. 



Asparagin. 



Other amido 

 compounds. 





20,5 



79.5 



68,8 



31.2 





26,2 



73.8 



78,1 



21,1 



100 parts of lupin-shoots containing 16,8 parts of asparagin 

 yielded, after 3 weeks vegetation in diffused daylight, 151 parts 

 of green plants with 23,9 parts of asparagin. l) The primary 

 amido-products disappear first, their carbon serves partially to 

 support respiration, while another part of their carbon together 

 with their nitrogen is found now in form of asparagin, and this 

 again disappears finally with the increase of available glucose, 

 formed by the function of the chlorophyll. The asparagin 

 evidently indicates the manner of the protein formation, it is 



1) Landw. Jahrb. 9, 41. The sulfur of the decomposed protein is converted into 

 sulfates, which later serve afterwards again in reconstruction of the proteids 

 (E. Schulze ; Tamann). 



