spiral vessels, that I should have been induced to suspect its affinity to Hydrangeæ, did not its other characters even more clearly indicate its true place in the natural system, which is, along with Deutzia and Decumaria, in the class Saxifrageæ. Datisca is another genus where the seed is of a very similar nature; the testa is formed of large cells so loosely connected that they may be separated without rupture of the walls, and though not so lax or produced at the apex, the funiculus expands, leaving a little cup at the base of the seed when detached ; the albumen and embryo are the same as in Saxifrageæ. Though in these respects, and in the adherent calyx, Datisceæ approach Hydrangeæ, in others they agree with Gunnera, as I have indicated under that genus.
In the figure of this plant, given by Poeppig, the aestivation of the corolla is imbricate, instead of valvate. Delessert's 'Icones' contain an excellent delineation, in which, however, the plicæ of the testa are omitted; and the stamens are quite different from those of the flowers I have examined, where they are very large and provided with stout and somewhat fleshy inflected filaments; possibly the flowers are unisexual. The pollen is globose, but obscurely three-lobed and rough on the surface.
Cornidia integerrima is common in Valdivia and Chiloe, where Mr. Bridges says that it is called "Coybo," and forms the largest tree of the country, being from 60-120 feet in height; it is further interesting from being the only Chilian representative of Hydrangeæ.
3. SAXIFRAGA, L.
1. Saxifraga exarata, Vill. Dauph. vol. iii. p. 674. t. 44. DC. Prodr. vol. iv. p. 27. S. Magellanica, Poiret, Encycl. vol. vi. p. 686. Don, Saxifrageæ in Trans. Soc. Linn. vol. xiii. p. 432. Sternberg, Rev. Sax. p. 39. t. 11. f. 1. Muscaria Magellanica, Haw. Enum. Sax. p. 38.
Varietates Antarcticæ sequentes sunt:—
Var. β, integrifolia; foliis superioribus integris.
Var. γ, laxa; foliis integris trifidisve laxius dispositis patentibus inferioribus reflexis.
Var. δ, breviscapa; dense cæspitosa, pedunculo brevissimo, flore inter folia summa sessili.
Hab. Strait of Magalhaens; Commerson. Port Famine; Capt. King. Mount Tarn, 2000 feet; C. Darwin, Esq.
Specimens, numerous and good, which I have examined, enable me unhesitatingly to refer this species to the S. exarata of Villars, as characterized by M. Seringe in De Candolle's Prodromus, and they entirely accord with examples gathered on Mount Olympus by Aucher-Eloy, and others from Iceland, labelled S. Grœnlandica (in Herb. Hook.). In Capt. King's collection, is one exactly similar to S. sileniflora, Chamisso, of Arctic N. W. America. Count Sternberg has sent the same plant as the trifid-leaved state of var. β, from Vallesia under the name of S. leucantha, Thomas; and I am unable to distinguish the specimens specifically from S. uniflora, Br., of Melville Island, which has sometimes three-flowered peduncles. The S. cæspitosa approaches all the above very closely, but its leaves are not so strongly nerved.
This is, in the south, as Protean a species as the S. hypnoides of the opposite hemisphere, though a much rarer plant. Capt. King's specimens vary so materially that De Candolle's character of S. Magellanica is inapplicable to all the states. The leaves are entire or trifid, very densely imbricated, or lax like those of S. Peruviana; the peduncles long or short, and one or many-flowered. The flowers are about the size of those of S. cæspitosa, a species which the present very closely resembles. It is not improbable that, eventually, some of the Peruvian Saxifrages will merge into this, the Andes thus seeming to afford a direct communication between the northern and southern hemispheres, of which this plant has availed itself. It appears to be scarce in Fuegia, and to affect the mountains, having only been gathered at a considerable elevation on the Andes, on the north side of the Strait of Magalhaens. It is singular that a species occurring at this height, should not be also seen at lower elevations in cooler latitudes, such
