catharticus. The long-styled form is not so common as the short-styled. The latter is said by Asa Gray to be the more fruitful of the two, as might have been expected from its appearing to produce less pollen, and from the grains being of smaller size; it is therefore the more highly feminine of the two. The long-styled form produces a greater number of flowers, which are clustered together instead of being sub- solitary; they yield some fruit, but as just stated are less fruitful than the other form, so that this form appears to be the more masculine of the two. On the supposition that we have here an hermaphrodite plant becoming dioecious, there are two points deserving notice; firstly, the greater length of the pistil in the incipient male form; and we have met with a nearly similar case in the male and hermaphrodite forms of Euonymus compared with the females. Secondly, the larger size of the pollen-grains in the more masculine flowers, which perhaps may be attributed to their having retained their normal size; whilst those in the incipient female flowers have been reduced. The long-styled form of R. lanceolatus seems to correspond with the males of R. catharticus which have a longer pistil and larger pollen-grains. Light will perhaps be thrown on the nature of the forms in this genus, as soon as the power of both kinds of pollen on both stigmas is ascertained. Several other species of Rhamnus are said to be dioecious or sub-dioecious. (7/10. Lecoq 'Geogr. Bot.' tome 5 1856 pages 420- 26.) On the other hand, R. frangula is an ordinary hermaphrodite, for my son found a large number of bushes all bearing an equal profusion of fruit.
Epigaea repens (ERICACEAE).
This plant appears to be in nearly the same state as Rhamnus catharticus. It is described by Asa Gray as existing under four forms. (7/11. 'American Journal of Science' July 1876. Also 'The American Naturalist' 1876 page 490.) (1.) With long style, perfect stigma, and short abortive stamens. (2.) Shorter style, but with stigma equally perfect, short abortive stamens. These two female forms amounted to 20 per cent of the specimens received from one locality in Maine; but all the fruiting specimens belonged to the first form. (3.) Style long, as in Number 1, but with stigma imperfect, stamens perfect. (4.) Style shorter than in the last, stigma imperfect, stamens perfect. These two latter forms are evidently males. Therefore, as Asa Gray remarks, "the flowers may be classified into two kinds, each with two modifications; the two main kinds characterised by the nature and perfection of the stigma, along with more or less abortion of the stamens; their modifications, by the length of the style." Mr. Meehan has described the extreme variability of the corolla and calyx in this plant, and shows that it is dioecious. (7/12. "Variations in Epigaea repens" 'Proc. Acad. Nat. Soc. of Philadelphia' May 1868 page 153.) It is much to be wished that the pollen-grains in the two male forms should be compared, and their fertilising power tried on the two female forms.
Ilex aquifolium (AQUIFOLIACEAE).
In the several works which I have consulted, one author alone says that the holly is dioecious. (7/13. Vaucher 'Hist. Phys. des Plantes d'Europe' 1841 tome 2 page 11.) During several years I have examined many plants, but have never found one that was really hermaphrodite. I mention this genus because the stamens in the female flowers, although quite destitute of pollen, are but slightly and sometimes not at all shorter than the perfect stamens in the male flowers. In the latter the ovary is small and the pistil is almost aborted. The filaments of the perfect stamens adhere for a greater length to the petals than in the female flowers. The corolla of the latter is rather smaller than that of the male. The male trees produce a greater number of flowers than the females. Asa Gray informs me that I. opaca, which represents in the United States our common holly, appears (judging from dried flowers) to be in a similar state; and so it is, according to Vaucher, with several other but not with all the species of the genus.