Chap. XVI. THE CROSSING OF VARIETIES. 107 



capsules ; whilst thirty-five dissimilarly-coloured unions yielded only twenty- 

 six good capsules. Besides the foregoing experiments, the purple V. phce- 

 niceum was crossed by a rose-coloured and a white variety of the same 

 species ; these two varieties were also crossed together, and these several 

 unions yielded less seed than V. phoeniceum by its own pollen. Hence it 

 follows from Mr. Scott's experiments, that in the genus Verbascum the 

 similarly and dissimilarly-coloured varieties of the same species behave, 

 when crossed, like closely allied but distinct species. 16 



This remarkable fact of the sexual affinity of similarly- coloured varieties, 

 as observed by Gartner and Mr. Scott, may not be of very rare occurrence ; 

 for the subject has not been attended to by others. The following case 

 is worth giving, partly to show how difficult it is to avoid error. Dr. 

 Herbert 17 has remarked that variously-coloured double varieties of the 

 hollyhock (Althcea rosea) may be raised with certainty by seed from plants 

 growing close together. I have been informed that nurserymen who raise 

 seed for sale do not separate their plants ; accordingly I procured seed 

 of eighteen named varieties; of these, eleven varieties produced sixty-two 

 plants all perfectly true to their kind; and seven produced forty-nine 

 plants, half of which were true and half false. Mr. Masters of Canterbury 

 has given me a more striking case ; he saved seed from a great bed of 

 twenty-four named varieties planted in closely adjoining rows, and each 

 variety reproduced itself truly with only sometimes a shade of difference in 

 tint. Now in the hollyhock the pollen, which is abundant, is matured and 

 nearly all shed before the stigma of the same flower is ready to receive 

 it; 18 and as bees covered with pollen incessantly fly from plant to plant, it 

 would appear that adjoining varieties could not escape being crossed. As, 

 however, this does not occur, it appeared to me probable that the pollen 



16 The following facts, given by I may add, of each species for its own 

 Kolreuter in his ' Dritte Fortsetzung,' pollen (Kolreuter, ' Dritte Forts.,' s. 39, 

 s. 34, 39, appear at first sight strongly and Gartner, ' Bastarderz.,' passim) 

 to confirm Mr. Scott's and Gartner's being a perfectly well - ascertained 

 statements ; and to a certain limited power. But the force of the foregoing- 

 extent they do so. Kolreuter asserts, facts is much lessened by Gartner's 

 from innumerable observations, that in- numerous experiments, for, differently 

 sects incessantly carry pollen from one from Kolreuter, he never once got 

 species and variety of Verbascum to (' Bastarderz.,' s. 307) an intermediate 

 another; and I can confirm this asser- tint when he crossed the yellow and 

 tion ; yet he found that the white and white flowered varieties of Verbascum. 

 yellow varieties of Verbascum lyclmitis So that the fact of the white and yellow 

 often grew wild mingled together : more- varieties keeping true to their colour by 

 over, he cultivated these two varieties seed does not prove that they were not 

 in considerable numbers during four mutually fertilised by the pollen carried 

 years in his garden, and they kept true by insects from one to the other, 

 by seed; but when he crossed them, 17 ' Amaryllidacese,' 1837, p. 366, 

 they produced flowers of an inter- Gartner has made a similar observa- 

 mediate tint. Hence it might have tion. 



been thought that both varieties must 18 Kolreuter first observed this fact, 



have a stronger elective affinity for the 'Mem. de l'Acad. de St. Petersburg,' vol. 



pollen of their own variety than for iii. p. 197. See also 0. K. Sprengel, 



that of the other ; this elective affinity, ' Das Entdeckte Geheimniss/ s. 345. 



