Some distinguished botanists, after Linnmus, term the common receptacle of the female fructification, which forms the characteristic mark of the genus Marchantia, a common calyx. But this is contrary to the analogy of all the other hepatic mosses, to the calyces of none of which it has the least resemblance; and it is very inconvenient in regard to this genus itself, as the supposed common calyx is totally unlike the proper calyx. The little cup at the base of the fruitstalk seems to us much better to merit the appellation ; and there can surely be no doubt, that the common receptacle is quite a peculiar organ. It is always supported on a footstalk. In form it is stel lated,hernispherical or conical,usually more or less lobed. In M. chenopoda of the West Indies, it appears as if halved, its three, four, or five acuminated segments being directed to one side only. The flowers are always on the lower side of the receptacles, and occur chiefly towards the summits of the lobes or segments.
In Targonia, what appears to be the calyx consists of a double membrane, the exterior of a reddish purple, the interior more delicate, white, with hexagonal 'fleshes, in which meshes the supposed anthers of this moss are situ ated.
The calyx of Anthoceros is cylindrical, somewhat elongated; its orifice toothed, and at last reflected ; its structure exactly resembles that of the frond.
The calyx of Sphmrocarpus is inversely pear-shaped, not above a line in length, with a contracted orifice at the summit. It is described by Dillenius and Michell as at last splitting into two segments,—a division which does not appear to have been afterwards observed ; and hence many modern botanists suspect some fallacy in the observation of these two illustrious authors on this par ticular point. In structure, the calyx exactly resembles the frond.
In Riccia glauca, the whole pistil in its younger state, with the exception of its apex, is immersed in the sub stance of the frond. Hence a calyx seems scarcely to be necessary to protect the fruit of this plant ; and none has been discovered. Monoclea is also destitute of a calyx, the cavity in the frond, from which the fruitstalk originates, probably serving in its stead.
The number ol pistilla tvhich occur within one calyx varies in different genera, and even in different species of the same genus. In Jungermannia, from three to eight or ten have been found in one calyx. In form they are generally linear or lanceolate ; but in J. pinguis, J. futcata, and J. multifida, they are short and ovate. Their colour is whitish or pale grey, with reddish longitudinal streaks. Generally one, sometimes two of these pistilla
become revile. The germen then swells and acquires an olive colour. The style, varying in length in different species, soon decays. The stigma is somewhat wider than the style.
In Marchantia polymorpha, two or three pistilla occur within each calyx. In the earliest period at which they have been observed, the germen is conical and olive brown. Never above one pistil in each calyx seems to become fertile. The style is brownish, and of consider able length ; the stigma scarcely wider than the style.
The calyx of Targionia contains always several pis tils, of which only one becomes fertile. The germen is oval, nearly sessile ; the style terminal and subulate, tubular ; the stigma concave.
In Anthocelos each calyx seems to contain only a sin gle pistil, which is cylindrical, tapering towards the sum mit, on which appears a brownish substance consisting of nunterous filaments, and this again is surmounted by a short style of the same colour. The stigma is not at all enlarged. The form nf the pistil and of the fruit of An thoceros, is that of a little horn, or tusk ; and hence the generic name. In Riccia glauca the germen, which is completely immersed in the frond till considerably ad vanced, is of a roundish form ; the style, rather short, of a dark purple colour, projects slightly above the surface of the frond ; the stigma appears truncated. This is the only hepatic moss in which the style is known to persist.
The pistils of Sphmrocarpus and Monoclea are com pletely unknown.
The calyptra, or exterior covering of the pistil, is known to exist in every hepatic moss, of which the fruit has been seen; with the exception of Sphmrocarpus, of which the flower is completely unknown. As in the fo liose mosses, it is attached by its base to the receptacle ; free around the germen; inseparably united to the style; and usually expanded at the summit, forming a consi derable portion of the stigma. ln several instances, how ever, as already mentioned, the stigma is not wider than the style. In texture it is usually mernbranaceous ; but in some of the frondose Jungermannize, such as J. epi phylla, J. pinguis, J. multifida, and J. furcata, and various foreign species, it is subcarnose. Its surface is usually smooth ; but in J. multifida it is tuberculated, and in J. furcata hispid. In the other frondose genera it is usually membranaceous and smooth. In Anthoceros it SeeMS to consist of a number of dark coloured filaments.