CHAP. IX. AND SELF-FERTILISED FLOWERS. 329 



growth, as in the case of the plants in the Tables F 

 and G, just considered. Thus the crossed and self-fer- 

 tilised plants of Ipomoea, Papaver, Reseda odorata, and 

 Limnanthes were almost equally fertile, yet the former 

 exceeded considerably in height the self-fertilised 

 plants. On the other hand, the crossed and self-fer- 

 tilised plants of Mimulus and Primula differed to an 

 extreme degree in innate fertility, but by no means to 

 a corresponding degree in height or vigour. 



In all the cases of self-fertilised flowers included in 

 Tables E, F, and G, these were fertilised with their 

 own pollen ; but there is another form of self-fertilisa- 

 tion, viz., by pollen from other flowers on the same 

 plant; but this latter method made no difference in 

 comparison with the former in the number of seeds 

 produced, or only a slight difference. Neither with 

 Digitalis nor Dianthus were more seeds produced by 

 the one method than by the other, to any trustworthy 

 degree. With Ipomoea rather more seeds, in the pro- 

 portion of 100 to 91, were produced from a cross 

 between flowers on the same plant than from strictly 

 self-fertilised flowers ; but I have reason to suspect that 

 the result was accidental. With Origanum vulgare, 

 however, a cross between flowers on plants propagated 

 by stolons from the same stock certainly increased 

 slightly their fertility. This likewise occurred, as we 

 shall see in the next section, with Eschscholtzia, 

 perhaps with Corydalis cava and Oncidium ; but not 

 so with Bignonia, Abutilon, Tabernsemontana, Senecio, 

 and apparently Eeseda odorata. 



Self-sterile Plants. 



The cases here to be described might have been 

 introduced in Table F, which gives the relative fer- 

 tility of flowsrs fertilised with their own pollen, and 



