FalMands, etc.] ■ FLORA ANTARCTICA. 295 



authors ofl'ers any explanation of their true nature. Poeppig * describes several species, and, trusting more to 

 a theoretical opinion of their origin, than to a careful analysis of the parts, or the definitions of De Candolle 

 and Guilleinin, he misapprehends the structure of the ovarium, considering it to be a compound body, made up of 

 three carpels combined, and of the plumose filaments, which are described in the generic character as Setae hypo- 

 gynae alternating with the ovaria, and in the observations on the genus are doubtfully called Staminodia. Lastly, 

 Endlieher f regards the single ovarium as compounded of six, enclosed in a three-parted involucre, three of 

 them fertile and three sterile, the latter being the plumose filaments. 



The female flower of Myzodendron consisting of a solitary ovarium, enclosed in the adherent tube of the 

 calyx, it is evident that the plumose setae must be a production of the calyx or ovarium. Their function and 

 appearance resemble the pappus of Composite, and particularly of Valeriana in being only fully developed during 

 the ripenmg of the seed. They cannot be compared with the four stout woody nerves of Tupeia Antarctica, which 

 ascending from the pedicel, terminate in the sarcocarp of its berry in four sharp points that arch over an opening 

 in the upper end of the endocarp of that plant, for the setas of Myzodendron contain no spiral vessels, and 

 the true nerves of the calyx, though very obscure, may be traced in some of the species, as in M. brackystacliyum, 

 where they appear alternating with the position of the setae (Plate CV. /. 11). 



The tissue of which these setae are composed, is identical with what forms the sarcocarp of Tupeia and Viscum, 

 namely, elongated viscid cells of great tenuity filled with a glutinous matter ; in most Lorantliacear this tissue 

 surrounds the endocarp and at an early period deliquesces into a homogenous viscid fluid, like that of Viscum. When 

 looking over the plants of this order, in Dr. Lindley's herbarium, I remarked one \ whose ripe pericarp had burst 

 during pressure and emitted a cottony substance ; that gentleman liberally gave me specimens for examination, 

 which showed the sarcocarp to be intermediate in its nature between that of Tupeia and of Myzodendron, being 

 feathery and neither so deliquescent as in the former, nor elaborated into such a peculiar organ as in the latter. 



The elaboration of these setae, from cellular tissue, cannot be regarded otherwise than a very singular 

 phenomenon, and, so far as my observations serve, it appears that it is merely the result of a rapid elongation of 

 cellular tissue. The viscid substance, then, in this genus, instead of surrounding the endocarp, is confined within 

 three fissures, and there collected into a terete or compressed body, which, escaping froni its confinement, rapidly 

 elongates from the growth of the cells which compose it, more than from the addition of new matter. The plumose 

 appearance is caused by the separation of some of the utricles, which diverge on all sides in the species in winch 

 the setae are terete, or in their opposite margins when the latter are compressed. Of all the species, the setae of 

 M. oblongifolium are the longest, and there are various gradations in length and tenuity between them and those of 

 M.puuctidatuni. The M. Unearifolium,§ DC, has not only very long and slender filaments, but its whole endo- 

 carp is at times surrounded with a feathery substance, which is thus not, as in its congeners, confined in loculi : 

 when placed in water this feathery substance deliquesces. In M. imbricatum, Pcepp., the fissures of the pericarp 

 are, according to the author of that species, filled with undivided stout obtuse filaments, collected together at the 

 base, and never exserted. 



I need scarcely allude to the fact, that the function performed by the gluten of Viscum and the feathery setae 

 of Myzodendron is identical, though effected in a different way, and that it affords a singular instance of nature's 

 employing the same means in a very dissimilar manner to the attainment of the same end. The viscid matter of 



* Guillemiu in Delessert's Icones Selectaa, vol. iii. p. 47. 



t Endlieher, Genera Plantarum, p. 800. n. 4581. 



% Lepidoceras Dombeyi, vid. supra, p. 293. 



§ A name which, without any assigned reason, has been altered to lineare in the Nova Genera et Species Plant. 

 Cliil. et Perm. 



