196 PETUNIA VIOL ACE A. CHAP. VI. 



crossed offspring. It is unfortunate that I did not turn these 

 plants out of doors, so as to observe their relative fertility, for I 

 compared the pollen from some of the crossed and self-fertilised 

 plants in Pot I, Table LXXXI., and there was a marked dif- 

 ference in its state ; that of the crossed plants contained hardly 

 any bad and empty grains, whilst such abounded in the pollen 

 of the self-fertilised plants. 



The Effects of a Gross with a fresh Stock. I procured from a 

 garden in Westerham, whence my plants originally came, a 

 fresh plant differing in no respect from mine except in the 

 colour of the flowers, which was a fine purple. But this plant 

 must have been exposed during at least four generations to very 

 different conditions from those to which my plants had been 

 subjected, as these had been grown in pots in the green- 

 house. Eight flowers on the self-fertilised plants in Table 

 LXXXI., of the last or fourth self-fertilised generation, were 

 fertilised with pollen from this fresh stock ; all eight produced 

 capsules containing together by weight 5 '01 grains of seeds. 

 The plants raised from these seeds may be called the Westerham- 

 crossed. 



Eight flowers on the crossed plants of the last or fourth genera- 

 tion in Table LXXXI. were again crossed with pollen from one 

 of the other crossed plants, and produced five capsules, contain- 

 ing by weight 2 '07 grains of seeds. The plants raised from 

 these seeds may be called the intercrossed ; and these form the 

 fifth intercrossed generation. 



Eight flowers on the self-fertilised plants of the same genera- 

 tion in Table LXXXI. were again self-fertilised, and produced 

 seven capsules, containing by weight 2'1 grains of seeds. The 

 self-fertilised plants raised from these seeds form the fifth self- 

 fertilised generation. These latter plants and the intercrossed 

 are comparable in all respects with the crossed and self-fertilised 

 plants of the four previous generations. 



From the foregoing data it is easy to calculate that, 



Or. Weight 



of Seed. 



Ten Westerham-crossed capsules would have contained 6 '26 

 Ten intercrossed capsules would have contained . . 4 ' 14 

 Ten self-fertilised capsules would have contained 3 '00 



We thus get the following ratios : 



