CHAP. V. HETEROSTYLED DIMORPHIC PLANTS. 235 



out of doors, they became during the two following 

 years much more dwarfed in stature and produced very 

 few flower-stems; and although they must have been 

 legitimately fertilised by insects, they yielded capsules, 

 compared with those produced by the surrounding legiti- 

 mate plants, in the ratio only of 5 to 100 ! It is there- 

 fore certain that illegitimate fertilisation, continued 

 during successive generations, affects the powers of 

 growth and fertility of P. veris to an extraordinary de- 

 gree; more especially when the plants are exposed to 

 ordinary conditions of life, instead of being protected in 

 a greenhouse. 



Equal-styled red variety of P. veris. Mr. Scott has 

 described* a plant of this kind growing in the Botanic Gar- 

 den of Edinburgh. He states that it was highly self -fertile, 

 although insects were excluded: and he explains this fact 

 by showing, first, that the anthers and stigma are in close 

 apposition, and that the stamens in length, position and 

 size of their pollen-grains resemble those of the short-styled 

 form, whilst the pistil resembles that of the long-styled 

 form, both in length and in the structure of the stigma. 

 Hence the self-union of this variety is, in fact, a legitimate 

 union, and consequently is highly fertile. Mr. Scott fur- 

 ther states that this variety yielded very few seeds when 

 fertilised by either the long- or short-styled common cow- 

 slip, and, again, that both forms of the latter, when fer- 

 tilised by the equal-styled variety, likewise produced very 

 few seeds. But his experiments with the cowslip were few, 

 and my results do not confirm his in any uniform manner. 



I raised twenty plants from self -fertilised seed sent me 

 by Mr. Scott; and they all produced red flowers, varying 

 slightly in tint. Of these, two were strictly long-styled 

 both in structure and in function; for their reproductive 

 powers were tested by crosses with both forms of the com- 

 mon cowslip. Six plants were equal-styled; but on the 

 same plant the pistil varied a good deal in length during 

 different seasons. This was likewise the case, according to 



'Proc. Linn. Soc.' vol. viii. (1864), p. 105. 



