| Mr. Brown, on the Proteaceae of Jussieu. | 27 |
doubted importance in determining genera, and even in the primary division of the order it appears to be of nearly equal consequence with the fruit itself; for, in dividing the order into two sections from the structure of the ovarium, it will be found that while all the single-seeded genera have each flower subtended by a proper bractea, or more rarely are without one, those with two or more seeds have, with very few exceptions, the flowers of their spikes of clusters disposed in pairs, each pair being furnished with only one bractea common to both flowers: it may also be observed that all the American and two thirds of the New Holland species have this mode of inflorescence, while only one instance of it occurs in Africa.
The single envelope of the stamina and pistillum in Proteaceæ I have, with Jussieu, denominated calyx, chiefly because the stamina, of equal number with its laciniæ, are constantly opposite to them, and from the close analogy subsisting between this family and that of Thymeleæ, in which I believe the greater number of botanists will allow that this envelope is really calyx: and as this latter argument may be considered as the stronger, I shall endeavour to establish the identity of this organ in these two families. In several of the Thymeleæ, especially in Pimelea, the lower part of the tube of the calyx is, as it were, jointed with the upper; after the falling off of which, it remains surrounding the fruit: this is also the case in several genera of Proteaceæ, as in Adenanthos of Labillardiere, in Isopogon, in Grevillea Chrysodendron, and still more remarkably in Franklandia, in which the persistent tube becomes indurated and even nearly woody, a change surely not likely to take place in a genuine corolla. But though I have thus adopted the language of Jussieu, I am decidedly of opinion that, in all families having a single en-
| e 2 | velope, |
