60 SWEET PEAS 



note the evidence there is either for or against Mendelism and its 

 application to the crossing of Sweet Peas. A remarkable instance 

 in support of Mendelism is recorded by Mr. C. C. Hurst, Burbage, 

 among the following varieties ; specimen flowers of Black Knight, 

 Sadie Burpee, Pink Cupid, White Cupid, Salopian, and their 

 hybrid forms, showing Mendelian dominance in F a (first gener- 

 ation) of red over white, purple over red, tall over Cupid, long over 

 round pollen grains, whilst the segregation in F 2 (breaking up in the 

 second generation) and the purity of recessives in F 3 were in 

 accordance with Mendelian laws. But Mr. Hurst also found that in a 

 few cases the hybrid characters were like neither parent, but appeared 

 to revert to an older or ancestral form, e.g. Black Knight x Pink Cupid 

 gave all wild purple cross-breds. A similar result was obtained at 

 Cambridge by crossing White Cupid (dwarf habit, round pollen 

 grains) with White Bush (tall growing, long pollen) ; the hybrid was 

 much taller than the taller parent and had purple, flowers, being, 

 therefore, a reversion both in height and colour. 



Yet another case of reversion even more remarkable than the 

 foregoing was obtained by two independent workers on Men- 

 delian laws. Most Sweet Peas it might be observed have long 

 pollen grains, but the white Emily Henderson has usually round 

 pollen. A few plants of this variety were found to have long pollen, 

 like most other Sweet Peas. Now, the round pollen variety was 

 crossed with the long pollen variety. Not losing sight of the fact 

 that both varieties were one for practical purposes and having white 

 flowers, nevertheless the result of crossing gave seed, all of which 

 produced plants bearing flowers with chocolate purple standards 

 and purple wings. Although these instances of reversion do not 

 conform to the law already described, yet Mendelian workers reason- 

 ably claim that such cases may occur in accordance with relative 

 laws so far imperfectly understood, and here it might be pointed out 

 that this study is still quite in its infancy to which its many imper- 

 fections should be attributed. Strange to say, Mendel's work, 

 conducted over fifty years ago, remained practically unknown to the 

 world until the year 1900, when his patient investigations were 

 re-discovered and made known to science. 



In conclusion, let it not be imagined that by crossing, say, 

 Countess Spencer with Lady Grisel Hamilton that the resultant 

 crosses will be all pinks or all lavenders. Some Sweet Peas never 

 have been, and probably never will be, fixed, and to none does this 

 apply more than those of the Countess Spencer type. In crossing 



