CHAP. V. HETEROSTYLED DIMORPHIC PLANTS. 223 



scssed little interest if it had consisted of a mere 

 change of structure ; but this is accompanied by modi- 

 fied fertility. Its occurrence apparently stands in 

 close relation with the illegitimate birth of the parent 

 plant; but to this whole subject I shall hereafter 

 recur. 



PRIMULA AURICULA. 



Although I made no experiments on the illegitimate offspring 

 of this species, I refer to it for two reasons : First, because 

 I have observed two equal-styled plants in which the pistil 

 resembled in all respects that of the long-styled form, whilst 

 the stamens had become elongated as in the short-styled form, 

 BO that the stigma was almost surrounded by the anthers. The 

 pollen-grains, however, of the elongated stamens resembled in 

 their small size those of the shorter stamens proper to the long- 

 styled form. Hence these plants have become equal-styled by 

 the increased length of the stamens, instead of, as with P. 

 Sinensi*, by the diminished length of the pistil. Mr. J. Scott 

 observed five other plants in the same state, and he shows * that 

 one of them, when self-fertilised, yielded more seed than an 

 ordinary long- or short-styled form would have done when 

 similarly fertilised, but that it was far inferior in fertility to 

 either form when legitimately crossed. Hence it appears that 

 the male and female organs of this equal-styled variety have 

 been modified in some special manner, not only in structure 

 but in functional powers. This, moreover, is shown by the 

 singular fact that both the long-styled and short-styled plants, 

 fertilised with pollen from the equal-styled variety, yield a 

 lower average of seed than when these two forms are fertilised 

 with their own pollen. 



The second point which deserves notice is that florists always 

 throw away the long-styled plants, and save seed exclusively 

 from the short-styled form. Nevertheless, as Mr. Scott was 

 informed by a man who raises this species extensively in Scot- 

 land, about one-fourth of the seedlings appear long-styled ; so 

 that the short-styled form of the Auricula, when fertilised by 

 its own pollen, does not reproduce the same form in so large a 

 proportion as in the case of P. Sinensis, We may further infer 



* 'Journal Proc. Linn. Soc.' viii. (18C4) p. 91. 



