374 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN 



The numbers of self-fertile and self-sterile plants are nearly equal 

 for most of the series, giving a total of 41 self-sterile and 39 self- 

 fertile plants. The latter exhibit, as in the case of self-fertile 

 plants of the preceding generation, degrees of self-fertility varying 

 from high to very low, the a\-erage per plant, determined as 

 already described, ranging from i per cent to 52 per cent. 



The facts regarding the flower color of these F2 hybrids are of 

 interest as evidence of the actual occurrence of self-fertility. All 

 the plants included in table 4 are of the F2 generation of crosses 

 between the white-flowered wild plant A and the blue-flowered 

 plants nos. j and 22 of the cultivated chicory (E series). The Fi 

 parents were all blue-flowered, the color being a light-blue chicory 

 with flowers frequently of a lavender-violet shade. The F2 

 generation recorded in table 4 split up into 46 blue-flowered and 

 25 white-flowered plants. The shade of blue varied greatly among 

 the blue-flowered plants and of the plants classed as white- 

 flowered 3 showed a noticeable variation from the usual type of 

 white flower. The plants A, B, and C, and all the plants thus 

 far grown from crosses between them, possess flowers that are 

 pure white except for a decided and continuous blue stripe ex- 

 tending up the middle of each anther, making well-marked and 

 conspicuous stripes in the ring of anthers. This is also the case 

 in most blue-flowered plants in my cultures, although the stripes are 

 here usually somewhat more intense. Plants (E22 X A)-io-, nos. 7 

 and 8 of series i and no. 10 of series 2, however, had flowers with 

 the blue stripes much reduced, and in no. 7 there were only faint 

 traces of them. In a general grouping of white-flowered and blue- 

 flowered, the splitting of this F2 generation in respect to flower 

 color does not very closely conform to the so-called Mendelian 

 formula for a monohybrid ratio. The splitting in this generation, 

 however, is indicative that the seed set by the -Fi generation were 

 the result of self-fertilization and not due to parthenogenesis which 

 may have developed. 



Self-fertility and self- sterility among plants of the Fz generation 

 grown from seed of self -fertile Fi plants. — In 191 5 several pedigreed 

 cultures were grown from self-fertilized seed obtained from various 

 of the F2 plants. The results of self-pollinations on these plants 

 are tabulated in table 5. 



