THE FORMATION OF PROTEIDS IN PLANT-CELLS. 55 
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grow in solutions containing as sole organic matter sulfonal 
(0,2%). 
Of course sulfuretted hydrogen is only produced in the neces¬ 
sary amount for immediate need, as accumulation would be 
noxious; experiments intented to prove that H 2 S as such can be 
assimilated, meet for obvious reasons with some difficulties. 
Our considerations, therefore, lead logically to the conclu¬ 
sion, that the atomic groups, serving for the formation of proteins 
are three very reactive combinations : 
Form-aldehyde, ammonia and sulfuretted hydrogen. 
II. The Formation of Proteids in 
Chlorophyll-bearing Plants. 
As chlorophyll-bearing plants produce by assimilation car¬ 
bohydrates, it is natural that such well suited compounds 
should form here also the main source of carbon for the synthe¬ 
sis of proteids. 1 ) Nitrates or ammonium salts furnish the nitro¬ 
gen, sulfates the sulfur. The chemical behaviour of the protein 
compounds indicates very clearly, that neither the nitrogen 
nor the sulfur is connected with oxygen, but only with carbon 
and hydrogen. It follows, therefore, that reduction of the 
nitrates and sulfates has to take place, here as well as in the 
case with the lower fungi. If all conditions are otherwise 
favorable, then the synthetical work proceeds so rapidly that 
the intermediate steps cannot be directly traced. From numer¬ 
ous observations, however, the conclusion appears justified 
that it is asparagin to which an important rôle must be attributed 
in this connection, a conclusion which at first was arrived by 
the ingenious Th. H artig. Borodin , Pfeffer and Kellner declared 
asparagin to be the form, in which the transportation of albu¬ 
minous bodies takes place. The most important investigations, 
however, we owe to E. Schulze and his school. 
Asparagin has been found normally in many plants, but under 
special conditions in still more cases. The root of Althaea contains 
1) It can hardly be doubted, that all such substances as are capable of being 
converted into starch , as glycerine (Arthur Meyer , Laurent) or glycol or methyl alcohol 
( Th . Bokorny) also serve as sources of carbon for the formation of protein compounds 
Also the combination of formic aldehyde with primary sodium sulfite may be used 
under certain circumstances (Th Bokorny). 
