R. P. Gregory 91 



a group of foliar carpels', surrounding an axis on which are borne naked 

 ovules. Proliferation of the axis is frequent. Hitherto I have not been 

 able to raise any seed from these plants, but some cuttings, taken late 

 in the season and only coming into flower in May last, have developed 

 what appear to be normal ovaries, and it is hoped that experiments 

 will be possible in the future. 



Inheritance of ordinary double. 



The ordinary form of doubleness is a recessive character^ When 

 crossed with singles, it gives a single F^, which on self-fertilization 

 gives singles and doubles in the proportion of 3 : 1. The actual 

 numbers obtained in 15 families are 762 singles, 284 doubles 

 {expectation: 78J^5 : 261-5)\ 



The double race used in all the foregoing experiments had its origin in a white single 

 obtained from a nurseryman in 1903. The plant proved to be heterozygous, throwing 

 singles and doubles. Every degree of doubleness was exhibited among the various 

 individuals of this race, and the phenomenon was repeated in some of our F^s. On 

 the other hand, certain plants, derived from the same strain, produced nothing but 

 full doubles, and in the Fjs from their crosses with singles, the distinction between 

 the singles and the doubles was quite sharp, all the latter being fuUy double. 



Characters of the "Eye" of the Flower. 



In the majority of horticultural strains the yellow or yellowish-green 

 " eye " of the flower occupies a small and well-defined area round the 

 mouth of the corolla tube. Besides this type of eye there exist two 

 other kinds; in the first, the eye occupies a much larger area, the 

 yellow colour extending well over the bases of the corolla lobes 

 ("Primrose Queen," Plate XXX, fig. 12 and Plate XXXII, figs. 62 

 and 63, No. 37/9) ; the second type is represented by the white-flowered 

 race " Queen Alexandra," in which the eye is not distinguished from 

 the rest of the corolla, the whole flower being uniformly white (Plate 

 XXX, fig. 11 and Plate XXXII, fig. 62, No. 34/9). 



Eye-characters are inherited quite independently of any of the 

 other characters which I have studied, but they affect certain other 

 characters with which they may occur in combination in the same 



1 Cf. Masters, loc. cit. pp. 262, 297. 



'•^ Bateson, Mendel's Principles of Heredity, Camb. Univ. Press, 1910, p. 199. 



3 The discrepancy is almost entirely due to one F^ family which consisted of 66 singles 

 and 45 doubles. Five other F2S from the same parents however gave 188 singles, 

 61 doubles. 



7—2 



