CHAP. VI. ON HETEROSTYLED PLANTS. 373 



of nature any single plant of a trimorphic species no 

 doubt produces all three forms ; and this may be ac- 

 counted for either by its several flowers being sepa- 

 rately fertilised by both the other forms, as Hildebrand 

 supposes; or by pollen from both the other forms 

 being deposited by insects on the stigma of the same 

 flower. 



Equal-styled varieties. The tendency of the di- 

 morphic species of Primula to produce equal-styled 

 varieties deserves notice. Cases of this kind have 

 been observed, as shown in the last chapter, in no less 

 than six species, namely, P. veris, vulgaris, Sinensis, 

 auricula, farinosa, and elatior. In the case of P. veris, 

 the stamens resemble in length, position and size 

 of their pollen-grains the stamens of the short-styled 

 form; whilst the pistil closely resembles that of the 

 long-styled, but as it varies much in length, one proper 

 to the short-styled form appears to have been elongated 

 and to have assumed at the same time the functions 

 of a long-styled pistil. Consequently the flowers are 

 capable of spontaneous self-fertilisation of a legiti- 

 mate nature and yield a full complement of seed, or 

 even more than the number produced by ordinary 

 flowers legitimately fertilised. With P. Sinensis, on 

 the other hand, the stamens resemble in all respects 

 the shorter ones proper to the long-styled form, whilst 

 the pistil makes a near approach to that of the short- 

 styled, but as it varies in length, it would appear as 

 if a long-styled pistil had been reduced in length and 

 modified in function. The flowers in this case as in 

 the last are capable of spontaneous legitimate ferti- 

 lisation, and are rather more productive than ordinary 



of nature with some flowers on the greatly preponderated in number; 



same plant long-styled, others there being 61 of this form to 9 



short-styled and others equal- of the short-styled and 15 of the 



styled ; and the long-styled form equal-styled. 



