242 BACTERIAL POISONS. 



interchangeable acid radicals. This view is supported not 

 only in the case of beet-root, where choline and betaiue 

 exist together, but the same two bases have been observed 

 in cotton-seeds. A similar coexistence was observed in the 

 toad-stool (Agaricus muscarius), in which choline and mus- 

 carine were found. And, lastly, the same condition holds 

 true probably for mytilotoxine and betaiue, which were 

 shown to be present together in poisonous mussels. 



Lecithin cannot always be regarded as the source of 

 choline in plants, since this base is known to occur as a 

 glucoside in the seeds of white mustard. The sinapin de- 

 composes according to the equation : 



C,,H,3NO, + 2H,0 = C,Hi,FO, + C,,H,0,. 



Sinapin. Choline. Sinapic Acid. 



According to Schui.ze (1891) the choline which is iso- 

 lated from pea- and vetch-seeds exists preformed in the 

 seeds, and does not result from lecithin by the process of 

 extraction. This is also probably true with reference to 

 cottonseed-cake. The condition in which betaine exists is 

 not determined. 



The protoplasm itself is another possible source of choline 

 as well as of other nitrogenous bases, as xanthine, etc. We 

 know from Drechsel's brilliant investigation (1890) that 

 casein on treatment with hydrochloric acid and stannous 

 chloride yields ammonia, araido acids, and organic bases — 

 lysatine, CgHijNjOj, and lysatinine, CgHuNjO — homo- 

 logues of creatine, C^HgNjOj, and creatinine, C^H^NjO. 

 From lysatinine urea can be readily obtained by treatment 

 with baryta. Subsequently, Siegfried (1891) showed that 

 vegetable protoplasm (conglutin from lupine) when treated 

 in the same way yields similar products. Later, Schulze 

 demonstrated that the base, arginine, CJI^^Nfi^, is formed 

 in lupine sprouts at the expense of the proteids present, and 

 he pointed out that this base is probably related to lysatine, 

 from which it diifers only by NH (see next chapter). 



