48 KozLOwsKi : Primary Synthesis of Protfjds 



as to the true origin of oxalic acid in plants, is the distribution of 

 that compound in different organs of the plant. This point, as 

 regards the oxalic acid bound to the calcium and forming in- 

 soluble crystals, was very carefully studied by Schimper * and by 



Kohl.t 



The former distinguishes four types of calcium oxalates, adding 



a new one to the three proposed by Schimper : (i) The/;7;;/^?;7>^ are 

 found in buds and are produced independently of assimilation ; (2) 

 The secondaries originate in the chlorophylic parenchyma and are 

 connected with assimilation ; (3) The tertiaiics are found in the 

 neighborhood of sclercnchymatous cells and also in fruits and seeds, 

 where reserve-substances are accumulated ; (4) The quaternaries 

 arc deposited in leaves in the autumn and remain there. 



Beginning now with the fourth category, we know, that in 

 the autumn new proteids are not formed in leaves, but on the con- 

 trary, the larger portion of those that constitute the protoplasm of 

 the cells, is dissolved and transferred into the stem ; this transfer 

 is most probably accomplished after the splitting of the proteids 

 into amides and carbohydrates. The most abundant production 

 of oxalic acid in plants is then due to the decomposition of pro- 

 teids. It can be objected that the larger part of oxalic acid could 

 have been produced at any earlier period of development of leaves 

 being then in form of soluble compounds and that the sudden ap- 

 pearance of a large amount of crystals in autumn is due to the 

 supply of calcium. But we have no reason for supposing that 



large amounts of calcium are brought into the leaves at a time 

 when their vital functions are declining. 



In reality the above quoted results of Berthelot and Andre 

 concerning the distribution of oxalic acid in Rnniex acetosa, con- 

 taining a Urge amount of soluble oxalates seems to contra- 

 dict our conclusion ; but the same authors found in other plants 

 {Aniarantus caudatiis, Oicnopodinm qninoa) quite opposite rela- 

 tions, and they add, after having presented the results of analysis of 

 the first of these plants : " that these latter plants show quite a 

 different mode of generation and physiological functions " (Ceci ac- 



*The above quoted article in Bot. Zeitung, l888. 



t Anatomisch-physiologische Untersuchungen iiber Kalksaltze und Kieselsaure in 



den Pflanzen, 1889. 



