Chap. XXL THE CROSSING OF VARIETIES. 85 



by its own pollen (eight capsules), and by that of the yellow variety 

 (five capsules), yielded seed in the proportion of 100 to 79. So that 

 in every case the unions of similarly-coloured varieties of the same 

 ppecies were more fertile than the unions of dissimilarly- coloured 

 varieties ; when all the cases are grouped together, the difference of 

 fertility is as 100 to 86. Some additional trials were made, and 

 altogether thirty-six similarly-coloured unions yielded thirty-five 

 good capsules ; whilst thirty-five dissimilarly-coloured unions yielded 

 only twenty-six good capsules. Besides the foregoing experiments, 

 the purple V. phceniceum 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. pftce- 

 niceum by its own pollen. Hence it follows from Mr. Scott's experi- 

 ments, that in the genus Yerbascum the similarly and dissimilarly- 

 coloured varieties of the same species behave, when crossed, like 

 closely allied but distinct species. 18 



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 19 has remarked that variously- 

 coloured double varieties of the Hollyhock (Alihea 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 

 2Dlants all perfectly true to their kind; and seven produced forty- 

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



18 The folio wing facts, given by of their own variety than for that of 

 Kolreuter in his ' Dritte Forisetzung,' the other ; this elective affinity, I 

 ss. 34, 39, appear at first sight strongly may add of each species for its own 

 to confirm Mr. Scott's and Gartner's pollen (Kolreuter, ' Dritte Forts.' s. 

 statements; and to a certain limited 39, and Gartner, ' Bastarderz., j>jass»n) 

 extent they do so. Kolreuter asserts, being a perfectly well-ascertained 

 from innumerable observations, that power. But the force of the fore- 

 insects incessantly carry pollen from going facts is much lessened by 

 one species and variety of Verbascum Gartner's numerous experiments, for, 

 to another ; and I can confirm this differently from Kolreuter, he never 

 assertion ; yet he found that the once got (' Bastarderz.,' s. 307) an 

 white and yellow varieties of Verbas- intermediate tint when he crossed the 

 cum lychnitis often grew wild mingled yellow and white flowered varieties 

 together : moreover, he cultivated of Verbascum. So that the fact of 

 these two varieties in considerable the white and yellow varieties keep- 

 numbers during four years in his ing true to their colour by seed does 

 garden, and they kept true by seed ; not prove that they were not mutual- 

 but when he crossed them, they pro- ly fertilised by the pollen carried by 

 dnced flowers of an intermediate tint. insects from one to the other. 

 Hence it might have been thought 19 < AmaryllidaceaB,' 1837, p. 366. 

 that both varieties must have a Gartner has" made a similar observa- 

 stronger elective affinity for the pollen tion. 



