KozLOwsKi : Primary Synthesis of Proteids 51 



explained from the above statement, namely, that the necessary 

 amount of calcium is never lacking in this case, because these or- 

 gans being unable to produce the carbohydrates indispensable for 

 their growth, these bodies must be transferred to the other parts 

 of the plant, and that transfer is, as we know, fulfilled in form of a 

 combination with calcium. 



We can thus consider a large part if not all the oxalic acid 

 produced in plants^ as a final product of decomposition of proteids 

 in a certain degree analogous to the carbamide in animals. The 

 analogy is increased by the fact that the oxalic acid is either ejected 



I 



from plants in the fallen leaves, or reduced to a state of insolu- 

 bility from which, in most cases, it is never brought forth. It is 

 thus an excretion, comparable to the carbamide in animals. If 

 these inductions are true, we can propose a very general question : 

 What is the reason for such a difference betzueen terminal products of 

 decomposition of the proteid molecule in animals and in plants ? 



We find a fact of equal generality which enables us to answer 

 this question : that is, the reduction of nitric acid, common to all 

 chlorophylic plants. We do not know exactly the stages through 

 which this reduction goes, but it is not to be doubted that one of 

 them must be nitrous acid (NHO^). The salts of this acid are found 

 in plants only in very small amounts, but that is easily explained by 

 their quick transformation into other compounds. 



The action of nitrous acid or its anhydride upon the compounds 

 of an amidic type is very characteristic. When the reaction is 

 violent the place of the amido group (NHj is taken by the hydroxyl 

 group (HO), the nitrogen being set free \ in other circumstances 

 all the nitrogen remains combined with the radical, producing 

 a diazo compound, while the hydrogen of the amido group and a 

 part of the hydrogen of the radical is combined with the oxygen 

 of the nitrous acid. 



L 



These two modes of action of the nitrous acid are exemplified 

 by the following equations : 



If w'c take the oxamide (the amide of the oxalic acid) the result 

 will be oxalic acid, nitrogen and water : 



* Schimper admits that the whole amount of oxalic acid in plants need not neces- 

 sarily have the same origin {^ioc. cit. 69). 



