July IS. 1915 Heredity of Color in Phlox Drummondii 



297 



Table I. — Color of the progeny of two varieties of Phlox drummondii, the Eclipse and 



the Cornea 



o See explanation of white below. 



EXPLANATION OF SYMBOLS AND FACTORS IN TABLE I 



The results from the Fg hybrids suggest that the following factors are present in the 

 parents. These factors have been represented by symbols as indicated below. 



"E." A factor for dark eye color producing a denser coloration at thecenterof the 

 flower, or eye. E does not act in the absence of the color factors B, R, or I (PI. C, 

 fig. G), but is effective if any one of them is present. 



"e." The absence of an eye factor produces a white eye. The latter, unlike the 

 dark eye, seems to have a distinct pattern (PI. C, D, E). 



" B. " Presence of blue pigment. This is not a pure blue, but contains red, produc- 

 ing purple. The blue and red do not become dissociated, but are inherited together 

 throughout the series. This red seems to bear no relationship to the red (R) brought 

 in by the pollen parent, Carnea. 



"b." Absence of blue. 



"R." Presence of red. This is a distinct red factor which is inherited separately 

 from all others. The absence of the factors for color, B and R, produces white. 



"r." Absence of the red brought in by the pollen parent. 



"I." An intensifying factor which determines the degree of pigmentation. This 

 seems to affect the red only (PI. C, fig. A,B). This factor evidently carries with it a 

 considerable amount of red. Possibly the apparent intensification of the reds is 

 nothing more than the addition of more red — that is, R and I may each represent 

 distinct red factors. Plate C, figiu-e B, shows a bright violet of phenotypic formula 

 EEBBRRii, in which the intensifying factor I is absent. But in a similar series 

 (EEBBRRII), Plate C, figure A, where it is present, much additional red is devel- 



