222 PRIMULA VEPJS. CHAP. VI. 



168 good capsules, whilst the self-fertilised plants produced 

 only two such flower-stems, bearing only 6 capsules, half of 

 which were very poor ones. So that the fertility of the two lots, 

 judging by the number of capsules, was as 100 to 3 '5. 



In considering the great difference in height and the wonderful 

 difference in fertility between the two sets of plants, we should 

 bear in mind that this is the result of two distinct agencies. 

 The self-fertilised plants were the product of illegitimate fertili- 

 sation during five successive generations, in all of which, ex- 

 cepting the last, the plants had been fertilised with pollen taken 

 from a distinct individual belonging to the same form, but which 

 was more or less closely related. The plants had also been 

 subjected in each generation to closely similar conditions. This 

 treatment alone, as I know from other observations, would have 

 greatly reduced the size and fertility of the offspring. On the 

 other hand, the crossed plants were the offspring of long-styled 

 plants of the fourth illegitimate generation legitimately crossed 

 with pollen from a short-styled plant, which, as well as its pro- 

 genitors, had been exposed to very different conditions ; and this 

 latter circumstance alone would have given great vigour to the 

 offspring, as we may infer from the several analogous cases 

 already given. How much proportional weight ought to be at- 

 tributed to these two agencies, the one tending to injure the 

 self-fertilised offspring, and the other to benefit the crossed 

 offspring, cannot be determined. But we shall immediately 

 see that the greater part of the benefit, as far as increased 

 fertility is concerned, must be attributed to the cross having 

 been made with a fresh stock. 



PBIMULA VEEIS. 

 Equal-styled and red-flowered var. 



I have described in my paper ' On the Illegitimate Unions of 

 Dimorphic and Trimorphic Plants' this remarkable variety, which 

 was sent to me from Edinburgh by Mr. J. Scott. It possessed a 

 pistil proper to the long-styled form, and stamens proper to the 

 short-styled form ; so that it had lost the heterostyled or dimor- 

 phic character common to most of the species of the genus, 

 and may be compared with an hermaphrodite form of a bi- 

 sexual animal. Consequently the pollen and stigma of the 

 same flower are adapted for complete mutual fertilisation, instead 

 of its being necessary that pollen should be brought from oae 



