KozLOwsKi : Primary Synthesis of Proteids 57 



It is necessary to notice that this diagram does not require a 

 constant relation between the amount of protein and that of carbo- 

 hydrates in plants, a relation which really does not exist. The 

 quantitative relation between compounds containing nitrogen and 

 those without it in plants is within certain limits dependent upon 

 the relation of assimilation to the amount of nitric acid absorbed 

 from the soil. . The greater the amount of assimilated carbohy- 

 drates, the less the carbohydrates, which are derived from proteids, 

 will be burnt. On the contrary, when the amount of assimilated 

 carbohydrates is not sufficient the relative amount of nitrogen in 

 the plant will rise, and since in sucli conditions proteids cannot be 

 regenerated — that surplus will consist of amides and other nitric 

 compounds of a non-proteid character. Something like this we 

 find in the above quoted results of the analysis of plants grown 

 from seeds in darkness. {^Antc, p. 39.) 



But the amount of cellulose (and other soluble carbohydrates) 

 cannot exceed a certain maximum in respect to nitrogen, and that 

 maximum corresponds to such a state in which the assimilated 

 carbohydrates make up all the loss for respiration, a state probably 

 reached in plants when the conditions of feeding are normal. 



Some chemical and physiological facts indicate that in the 

 protcid molecule there are groups of atoms closely connected 

 tocrether and containing: each 6 atoms of carbon. That number 



. V-^x.x.. ^..^ v.w.....wxx.,j^ 



is basal for the carbohydrates found in organisms and fatty acids, 

 the most common in animals, containing a multiple of that num- 

 ber (the stearic C^gH^p^ 5 ^^^^ ^^^^^ ^i^^zPd^ ^^'^^ amides, 

 which are produced in organisms, or through the action of 

 chemical agents upon the proteids contain generally less than 6 

 atoms of carbon and the most typical of them, leucine is the 

 amido-capronic acid — CJIi^NO^. Only the less defined com- 

 pounds obtained by Schiitzenberger (and called by him leucines) 

 seem to make an exception to this rule, but we do not know 

 whether these arc chemical individuals or mixtures. All these 

 and many other physiological facts oblige us to admit a near con- 

 nection between proteids, fats and carbohydrates, and although 

 the transitions from one group to another cannot yet be accom- 

 plished in the laboratory, there is no doubt that it is accom- 

 plished continually in the organisms themselves. 



New York. 



