F. Keeble and E. F. Armstrong 291 



general rule that epidermal and bundle oxydases are present in the 

 corollas. 



These three categories are the dominant white, blue with white 

 inhibitory patches and the flaked varieties. 



(3) Flaked {Ever-sporting) Varieties. 



We will deal first with the flaked varieties. Snow King and 

 Mt. Blanc Star, the varieties of P. sinensis which we have investigated, 

 bear white flowers marked more or less prominently by splashes of 

 magenta. Sometimes a whole petal is magenta coloured and sometimes 

 a magenta flower appears among neighbouring magenta flaked flowers. 

 Although the amount of flaking varies very considerably the races breed 

 wellnigh true to this habit. Thus Mt. Blanc Star produces oflfspring 

 the great majority of which are flaked ; but it throws occasionally a 

 plant all the flowers of which are magenta coloured. These magenta 

 flowered plants may bear darker flakes of magenta on a lighter coloured 

 ground and the numbers in which they appear are said to be about two 

 per cent. The genetics of these flaked forms which is in course of 

 investigation by one of the present writers (see Keeble, 1910 a) need not 

 concern us here except in so far that it provides evidence of the exist- 

 ence in the petals of a partial inhibitor of pigment formation. 



Magenta-flaked white flowers of Mt. Blanc Star give much fainter 

 and far less regular oxydase reactions than are exhibited by any coloured 

 or recessive white varieties. They provide also a good illustration of 

 the relation between oxydase and pigmentation. For, as is exemplified 

 in the text-figure (Fig. 1), if, before treating the flower with the oxydase 

 reagent, the pigmented areas are recorded it is found that the distribution 

 of oxydase coincides very closely with that of the pigment. In the case 

 depicted in the text-figure a flower was chosen which had, in addition 

 to certain irregular magenta flakes, one petal of a uniform magenta 

 colour. A comparison of the distribution of pigment with that of the 

 oxydase shows that the magenta petal gave a well marked oxydase 

 reaction, that the magenta patches on other petals were also the seat of 

 a fair amount of oxydase and that the white areas gave no reaction. 



The absence of oxydase-reaction from the unpigmented parts of the 

 flower is noteworthy because it is the first piece of evidence which we 

 have been able to produce to show that failure to form pigment may be 

 connected with failure to yield the reaction for oxydase. 



Flowers of this kind, characterised by a considerable degree of fluctua- 

 tion of colour and by the localisation of such colour as they may have 



