In all these fifteen plants the anthers, occupying the same position as in the long-styled form, closely surrounded the stigma, which in one instance alone was slightly elongated. Notwithstanding this position of the stigma, the flowers, as the gardener assured me, did not yield many seeds; and this difference from the foregoing cases may perhaps have been caused by the pollen being bad, as in some of the Southampton equal-styled plants.]
CONCLUSIONS WITH RESPECT TO THE EQUAL-STYLED VARIETY OF P. Sinensis.
That this is a variation, and not a third or distinct form, as in the trimorphic genera Lythrum and Oxalis, is clear; for we have seen its first appearance in one out of a lot of illegitimate long-styled plants; and in the case of Mr. Duck's seedlings, long-styled plants, only slightly deviating from the normal state, as well as equal-styled plants were produced from the same self- fertilised parent. The position of the stamens in their proper place low down in the tube of the corolla, together with the small size of the pollen-grains, show, firstly, that the equal-styled variety is a modification of the long- styled form, and, secondly, that the pistil is the part which has varied most, as indeed was obvious in many of the plants. This variation is of frequent occurrence, and is strongly inherited when it has once appeared. It would, however, have possessed little interest if it had consisted of a mere change of structure; but this is accompanied by modified 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, so 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. Sinensis, 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. (5/8. 'Journal of the Proceedings of the Linnean Society' 8 1864 page 91.) 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 Scotland, 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 that the short-styled form is not rendered quite sterile by a long course of fertilisation with pollen of the same form: but as there would always be some liability to an occasional cross with the other form, we cannot tell how long self-fertilisation has been continued.
Primula farinosa.
Mr. Scott says that it is not at all uncommon to find equal-styled plants of this heterostyled species. (5/9. 'Journal of the Proceedings of the Linnean Society' 8 1864 page 115.) Judging from the size of the pollen-grains, these plants owe their structure, as in the case of P.