322 



Scientific Proceedings, Royal Dublin Society. 



Discussion of Results of Table III. 

 The outstanding feature in this class is the absence of active peroxidase 

 in all except two hybrids and the purple form of I. pumila. One is tempted 

 to regard the yellow form of /. pumila as differing from the purple in the 

 possession of an inhibitor in the veins, but more especially in the epidermis 

 of the flower. But if oxidases really do play the important role in the pro- 

 duction of anthocyan pigments which they are usually supposed to do, it is 

 very hard to explain the absence of reaction in the many deep purple forms 

 included in this group. Possibly the diffusion of the inhibitor from other 

 cells may account for the difficulty. The whole question, however, leaves 

 room for much further work. 



Table IY. 



Xiphion Group. 



