1912.] 



The Oxydases of Cytisus Adami. 



163 



The former receive only the oxydase of the purpureas branch, the latter 

 have at their disposal contributions from the. whole plant. 



The conclusions based on the results of treating petals with benzidine are 

 confirmed by those obtained with a-naphthol. For although this reagent 

 produces no definite epidermal reaction,* it gives rise to distinct bundle 

 oxydase reactions in the flowers of G. purpureus and purple C. Adami. On 

 the other hand, a-naphthol gives no direct oxydase reactions, neither in the 

 flowers of G. laburnum., typical G. Adami, nor in those of the yellow branches 

 of G. Adami. In these last-mentioned forms a-naphthol and hydrogen 

 peroxide produce the characteristic colour-reaction, whence it is to be 

 concluded that they contain peroxydase. 



As indicated in the accompanying diagrammatic representation of the 

 results described above, the accuracy of Baur's representation of C. Adami', 

 as a periclinal chimera is confirmed by a study of the oxydases of the flowers- 



The Oxydases <yf CyHsus Adami 

 C. Ada^m i. 



{^T^SZl*™- Purple /lowers ^l^lTJ^} 



^ Buy//lowers 1 



( n ° eP C id L e X r n°u X ^ Se - Yellow /lowers ► ^"I'VKurnST'} 



of the component species and of the synthetic form. Whether, however, the 

 growing points of G. Adami consist always of a single-layered mantle of 

 C. purpureus cells enveloping cells solely of the G. laburnum type must 

 remain for the present uncertain. 



It is not too much to suppose that, if the migration of oxydases is finally 

 proved and shown to be of general occurrence, considerable light will be 

 thrown on the nature of the, at present, puzzling differences in form between 

 the flowers of G. Adami and those of the component species, and in particular 

 it may help to elucidate the causes of differences which exist between the 

 flowers of G. purpureus and those of purpureus branches of the graft-hybrid. 



The facts now to be mentioned appear to point distinctly to a migration of 

 oxydase from cell to cell. The most elegant part of Baur's demonstration of 

 the peri-chimeral nature of G. Adami has reference to small groups of 

 cells containing red (anthocyan) pigment which occur in the neighbourhood 

 of the median line on the lower parts of the standards of flowers of C. AdamL 

 These patches of pigmented cells— described sometimes as honey-guides — 

 though visible on the surface of the intact flower are situated in the 



* See Keeble and Armstrong, loc. cit, 

 VOL. LXXXV. — B. 2 K 



