288 SOME RECENT RESEARCHES IN PLANT PHYSIOLOGY 



A second hypothesis as to their function has been 

 advanced by Mayer and Schoeffer (1913) namely, that 

 these bodies are the seat of the oxidation processes of the 

 cell. These authors appear to regard the mitochondries 

 as myelin forms namely, granules or droplets of a lipoid 

 nature and this view is also held by Lowschin (1913). 

 Guilliermond, however, considers them to be organoids of 

 the cell which are of universal occurrence. It would be 

 foreign to the purpose of the present chapter to discuss 

 this vexed question fully. 



REVIEW OF THEORIES or ANTHOCYANIN FORMATION. 

 The numerous researches upon the formation of the 

 anthocyanins may be roughly divided into three groups : 



1. The purely chemical investigations of Willstatter and 

 his school. These have shown that Wheldale was correct 

 in regarding the anthocyanins as related to the flavones. 



2. The researches of a biochemical nature upon the 

 relationship between the distribution of complete per- 

 oxidase systems and of anthocyanins. 



3. Physiological investigations upon the factors influ- 

 encing the production of anthocyanin. 



(a) Willtsatter has shown that a number of the antho- 

 cyanins are glucosides of various bodies isomeric with the 

 flavones. Hydrolysis removes the sugar, giving rise to 

 anthocyanidins. One of these cyanin he has obtained 

 in small quantity by the reduction of quercetin. The main 

 product, however, is allocyanidin, isomeric with cyanidin, 

 but differing in the fact that in it the pyrone ring is opened. 



Wheldale has investigated the red and magenta antho- 

 cyanins of Antirrhinum, which arise from apigenin or 

 luteolin. These have higher molecular weights and a higher 

 percentage of oxygen than have the parent flavones. They 

 are not glucosides, and appear to be more complex than 



