APPENDIX 345 



among a greater number solitary examples occur which transmit 

 the colour of the flowers unchanged to their offspring. The culti- 

 vated species of Dianthus afford an instructive example of this. 

 A white-flowered example of Dianthus caryophyllus, which itself 

 was derived from a white-flowered variety, was shut up during its 

 blooming period in a greenhouse; the numerous seeds obtained 

 therefrom yielded plants entirely white-flowered like itself. A 

 similar result was obtained from a sub-species, with red flowers 

 somewhat flushed with violet, and one with flowers white, striped 

 with red. Many others, on the other hand, which were similarly 

 protected, yielded progeny which were more or less variously 

 coloured and marked. 



Whoever studies the coloration which results, in ornamental 

 plants, from similar fertilisation, can hardly escape the conviction 

 that here also the development follows a definite law, which 

 possibly finds its expression in the combination of several inde- 

 pendent colour characters. 



Concluding Remarks 



It can hardly fail to be of interest to compare the observations 

 made regarding Pisum with the results arrived at by the two 

 authorities in this branch of knowledge, Kolreuter and Gartner, 

 in their investigations. According to the opinion of both, the 

 hybrids in outward appearance present either a form intermediate 

 between the original species, or they closely resemble either the 

 one or the other type, and sometimes can hardly be discriminated 

 from it. From their seeds usually arise, if the fertilisation was 

 effected by their own pollen, various forms which differ from the 

 normal type. As a rule, the majority of individuals obtained by 

 one fertilisation maintain the hybrid form, while some few others 

 come more like the seed parent, and one or other individual 

 approaches the pollen parent. This, however, is not the case with 

 all hybrids without exception. Sometimes the offspring have 

 more nearly approached, some the one and some the other of the 

 two original stocks, or they all incline more to one or the other 

 side; while in other cases they remain perfectly like the hybrid and 

 continue constant in their offspring. The hybrids of varieties 

 behave like hybrids of species, but they possess greater variability 

 of form and a more pronounced tendency to revert to the original 

 types. 



