I have already alluded to the rotation of each separate stigma in the long- styled form of Linum perenne. In both forms of the other heterostyled species and in the homostyled species of Linum which I have seen, the stigmatic surfaces face the centre of the flower, with the furrowed backs of the stigmas, to which the styles are attached, facing outwards. This is the case with the stigmas of the long-styled flowers of L. perenne whilst in bud. But by the time the flowers have expanded, the five stigmas twist round so as to face the circumference, owing to the torsion of that part of the style which lies beneath the stigma. I should state that the five stigmas do not always turn round completely, two or three sometimes facing only obliquely outwards. My observations were made during October; and it is not improbable that earlier in the season the torsion would have been more complete; for after two or three cold and wet days the movement was very imperfectly performed. The flowers should be examined shortly after their expansion, as their duration is brief; as soon as they begin to wither, the styles become spirally twisted all together, the original position of the parts being thus lost. He who will compare the structure of the whole flower in both forms of L. perenne and grandiflorum, and, as I may add, of L. flavum, will not doubt about the meaning of this torsion of the styles in the one form alone of L. perenne, as well as the meaning of the divergence of the stigmas in the short-styled form of all three species. It is absolutely necessary as we know, that insects should carry pollen from the flowers of the one form reciprocally to those of the other. Insects are attracted by five drops of nectar, secreted exteriorly at the base of the stamens, so that to reach these drops they must insert their proboscides outside the ring of broad filaments, between them and the petals. In the short-styled form of the above three species, the stigmas face the axis of the flower; and had the styles retained their original upright and central position, not only would the stigmas have presented their backs to the insects which sucked the flowers, but their front and fertile surfaces would have been separated from the entering insects by the ring of broad filaments, and would never have received any pollen. As it is, the styles diverge and pass out between the filaments. After this movement the short stigmas lie within the tube of the corolla; and their papillous surfaces being now turned upwards are necessarily brushed by every entering insect, and thus receive the required pollen.