102 Experiments ivith Primula sinensis 



I have not yet undertaken any systematic experiments with the 

 blue-flowered strains of Primula sinensis. Blues occurred among the 

 offspring of a certain magenta plant obtained in 1903, in such propor- 

 tions as to corroborate the more extended results obtained by Messrs 

 Sutton, which show that the blue colour is an ultimate recessive'. 



For the purpose of these experiments it has been found convenient 

 to work mainly with well-known horticultural strains, which provide a 

 series of fixed standards of colour. The colours of the races of which 

 principal use has been made are illustrated in Plate XXXI. For con- 

 venience of reference descriptions of the various types are given below, 



Description of strains used in expe7-iments on colour. 



Recessive White. 



" Snowdbift." (Tlate XXX, figs. 7, 10.) Fern-leaf, green stem, white, green stigma. 

 Pale colours. 



" Reading Pink." (Plate XXX, fig. 13.) Palmate, green stem, pale-pink, green stigma. 

 Full colours. 



Saluon Pink. Palmate, purplish-red stem (light), salmon-pink, gieen stigma, short 

 style. 



Rosy Magent.\. (Plate XXX, figs. 19, 20.) Palmate, purplish-red stem (light), 

 magenta (rosier than Fi type, light), green stigma. 



"Crimson King." (Plate XXX, fig. 9.) Palmate, purplieh-red stem (deep), deep 

 crimson, red stigma. 



"Orange King." (Plate XXX, figs. 3, 8.) Palmate, red (not purplish-red) stem, 

 pink flowers, red stigma. 

 Dominant Whites. 



Double White. Palmate, green stem with colour in leaf bases (Plate XXX, fig. 6), 

 double white flowers, green stigma. 



" Primrose Queen." (Plate XXX, fig. 12.) Palmate, purplish-red stem (light), white 

 flowers, green stigma, large yellow eye. 



"Queen Alexandra." (Plate XXX, fig. 11.) Palmate, purplish-red stem, white, 

 green stigma, white eye. 

 Colour uncertain (see p. 122). 



"Ivt-Leaf." (Plate XXX, fig. 5, Plate XXXII, fig. 60.) Palmate, uon-crenate, stellata, 

 green stems with colour in leaf bases-, flowers? very pale colour flaked, green 

 stigma. The "Ivy-leaf" is a very monstrous type, the nou-crenate character o£ 

 the leaves being always accompanied by partial abortion of the floral organs. 

 Stamens are often absent and the corolla may be reduced to a tube surrounding 

 the style, without petal-lobes. Petal-lobes, when developed, may be only small 

 strap-shaped structures. Owing to the poor development of the corolla the colour 

 of the plant used in the experiments cannot be determined with certainty. Such 

 plants as survive usually become fertile in the second year, producing however 



1 Bateson's Mendel's PriM'iples of Heredity, Camb. Univ. Press, 1909, p. 135. 

 ^ The colour is insufiiciently shown against the dark background in the plate. 



