222 



ESSENTIAL OEGAifS — STAMENS. 



the septum, which sometimes remains permanently complete, and 

 thus forms a quadrilocular (quatuoi; four, loculus, a pouch or box) or 

 tetrathecal [Tir^ag, four, SffAri, a sac) anther. The four cavities 

 are sometimes placed in apposition, as in Poranthera (fig. 355) and 

 Tetratheca juncea (fig. 356), and at other times two are placed above 

 and two below, as in Persea gratissima (fig. 357 I I). In general, 

 however, only two cavities remain in the anther, in consequence of the 

 more or less complete removal of the septum, in which case the anther 

 is said to be bilocular (bis, twice), or dithecal (Slg, twice) as seen in 

 figs. 354, 358. Sometimes the anther has a single cavity, and be- 

 comes unilocular (unus, one), or monothecal (/ioi/os, one), either by the 

 disappearance of the partition between the two lobes, or by the abortion 

 of one of its lobes, as in Styphelia Iseta (fig. 359) and Althaea offici- 

 nalis (fig. 360). Occasionally there are numerous cavities in the 

 anther, as in Viscum and Eafflesia. The number of loculi or cavities 

 is only seen when the anther opens. 



Fig. 356. 



Kg. 367. 



Fig. 359. 



The form of the anther-lobes varies. They are generally of a 

 more or less oval or elliptical form (figs. 354, 361 I). Sometimes 



Fig. 355, Quadrilocular anther, I, of Porauthera, attached to the filament, /, and opening 

 at the summit by four pores, p. Fig. 356. Quadrilocular anther of Tetratheca juncea. 

 1. The anther entire, with its four loculaments ending in one opening. 2. Anther cut 

 transversely, showing the four loculaments. Fig. 357. Anther of the Avocado pear (Persea 

 gratissima), composed of four cavities or loculaments, I I, united in pairs, one above the 

 other, and opening each by a valve, v. At the base of the filament, /, are two glands, ' 

 g g, which seem to be abortive stamens or staminodes, and which may represent stipules. 

 Fig. 358. Pendulous anther lobes, 1 1, of Mercurialis annua, supported on the filament, /, 

 and united by the connective, c. Fig. 359. Unilocular or monothecal anther of Styphelia 

 laeta, one of the Bpacridaceje, seen in front, 1, and behind, 2. /, Filament. Z, Anther. 

 Fig. 360. Unilocular anther of Althaaa officinalis, or Marsh mallow. One of the lobes of the 

 anther, I, abortive, f. Filament. 



