238 



Gates. 

 Table III. (contd.) 



Number 

 of 1912 culture 



Number of Fj 

 parent plant 



Character of buds 

 in parent Fi plant 



Ratio 



VI. (grandiflora )c rubncalyx) x grandiflora C^ 



Cult. 73. (a) . . IX. 4 ] red (Rr?) buds x grandifl. 



„ 74. (b) . . VI. 6 



„ 78. (c) . . VI. 6 



VII. (grandiflora x riibricalyx) x (rubricalyx x grandiflora). 



Cult. 75. (a) . . XII. I X IV. 2 ired fÄfl; x red (Rr) buds 

 76. (b) . . IX. 4 X VI. I red (Rr?) x red (Rr) buds 



Cult. 77 



XI. 9 X VII. I I green x green buds 



E. 2. Inheritance of the rubricalyx character, R. 



From the data presented in table III we are able to draw some 

 important conclusions regarding the inheritance of R. It mnst be 

 borne in mind that R represents the unit-difference between rubri- 

 calyx and rubrinervis, that it appeared suddenly as a mutation without 

 intermediates, and that it consists in a conspicuous red pigmentation 

 of the buds and other parts of the plant. In a former paper (Gates, 

 1911 b) coloured figures of the buds are showTi (plate 6) and a number 

 of cultures of rubricalyx crosses are described and tabulated (p. 365). 

 One or two of the latter are also included in pedigree i of this paper 

 (p. 216). 



The fact must be emphasized, that all the data of table III are 

 derived from plants which came into bloom, and in which in almost 

 every case the distinction between the R and r bud characters is so 

 clear as not to admit of the slightest doubt. The exceptions are given 

 in table IV and will be referred to later. The great majority of the 

 plants produced hundreds of flowers, making the distinction between 

 the two types so conspicuous that thej? can be distinguished at a glance 

 by any one. 



In the description of the Fj of the cross grandiflora x rubricalyx, 

 it has already been shown {vide supra, p. 230) that the ratio R : r 



{!) The Alabama race was used in the back-cross. 



