THE r6lE of oxydases IN THE FORMATION 

 OF THE ANTHOCYAN PIGMENTS OF PLANTS. 



Br FREDERICK KEEBLE, Sc.D, 



Professor of Botany, University College, Reading, 



Ain) E. FRANKLAND ARMSTRONG, D.Sc, Ph.D. 



— CONTENTS. 



PAOB 



I. Introduction and Methods 277 



n. The Distribntion of Oxydases in Plant- tissues .... 283 



A. The Oxydases in the Vegetative Members of Primula sinensis 283 



B. The Oxydases in the Flower of P. sinensis . . 289 



1. Self-coloured varieties 289 



2. Recessive white varieties 290 



3. Flaked (Ever-sporting) varieties .... 291 



C. The Oxydases of Dianthus barbatus (Sweet William) 293 



1. Ever-sporting varieties 293 



2. White varieties of Sweet William ... 294 



D. The Oxydases of Geranium sanguineum .... 295 



E. The Localisation of Oxydases in the Tissues of the Flower 



(P. sinensis) 296 



F. Dominant White Varieties 298 



G. The Nature of the Oxydases in Flowers .... 304 



1. The Oxydases and Peroxydases of P. sinensis . 304 



2. The Oxydases and Peroxydases of other flowers . 305 



3. The Influence of Light and Darkness on the 



Oxydase-content of plants 306 



I. Introduction and Methods. 



The progress of discovery with respect to the genetics of colour has 

 been so rapid of recent years as to outpace that of our knowledge of the 

 chemistry of pigment-formation in plants and animals. Thanks to the 

 labours of Bateson, Miss Saunders, Punnett, Gregory, Baur and many 



