CHAP. III. CROSSED AND SELF-FERTILISED PLANTS. 69 



Crvssed and self -fertilised Plants of the Sixth Generation. 

 from plants of the fifth generation crossed and self-fertilised in 

 the usual manner were sown on opposite sides of several pots. 

 On the self-fertilised side every single plant belonged to the tall 

 white variety. On the crossed side some plants belonged to this 

 variety, but the greater number approached in character to the 

 old and shorter kinds with smaller yellowish flowers blotched 

 with coppery brown. When the plants on both sides were from 

 2 to 3 inches in height they were equal, but when fully grown 

 the self- fertilised were decidedly the tallest and finest plants, but, 

 from want of time, they were not actually measured. In half 

 the pots the first plant which flowered was a self-fertilised one, 

 and in the other half a crossed one. And now another remark- 

 able change was clearly perceived, namely, that the self-fertilised 

 plants had become more self-fertile than the crossed. The 

 pots were all put under a net to exclude insects, and the crossed 

 plants produced spontaneously only fifty-five capsules, whilst 

 the self-fertilised plants produced eighty-one capsules, or as 100 

 to 147. The seeds from nine capsules of both lots were placed 

 in separate watch-glasses for comparison, and the self-fertilised 

 appeared rather the more numerous. Besides these sponta- 

 neously self-fertilised capsules, twenty flowers on the crossed 

 plants again crossed yielded sixteen capsules; twenty-five 

 flowers on the self-fertilised plants again self-fertilised yielded 

 seventeen capsules, and this is a larger proportional number of 

 capsules than was produced by the self-fertilised flowers on the 

 self-fertilised plants in the previous generations. The contents 

 of ten capsules of both these lots were compared in separate 

 watch-glasses, and the seeds from the self-fertilised appeared 

 decidedly more numerous than those from the crossed plants. 



Ciossed and self-fertilised Plants of the Seventh Generation. 

 Crossed and self-fertilised seeds from the crossed and self-ferti- 

 lised plants of the sixth generation were sown in the usual 

 manner on opposite sides of three pots, and the seedlings were 

 well and equally thinned. Every one of the self-fertilised plants 

 (and many were raised) in this, as well as in the eighth and ninth 

 generations, belonged to the tall white variety. Their uniformity 

 of character, in comparison with the seedlings first raised from 

 the purchased seed, was quite remarkable. On the other hand, 

 the crossed plants differed much in the tints of their flowers, 

 but not, I think, to so great a degree as those first raised. 

 I determined this time to measure the plants on both sides 



