ANDRGEC1UM, OB STAMENS. 251 



455. Of terms relating to adnation of stamens, besides the 

 general ones of hypogynous, perigynous, epigynuus (332), and 

 epipetalous, or aclnate with corolla, there is the special one of 



Gynandrous, having stamens borne upon the pistil, as in 

 Orchidaceae. In Cypripediurn, the filaments of two stamens, and 

 an enlarged sterile stamen behind, are adnate to a style, while 

 the two anthers are quite free (Fig. 492) ; in the proper Orchis 

 tribe (as in Fig. 4GO, 4G1), anther and stigma are consolidated 

 into one mass, and there is no evident style. 



456. A complete stamen consists of FILAMENT and ANTHER. 

 The latter is the functionally essential part of the organ, and 

 therefore is wanting only in abortive or sterile stamens. (345, 

 352, &c.) The filament, being only a stalk or support, may be 

 very short or wholly wanting : then the anther is sessile, just as 

 the blade of a leaf is said to be sessile when there is no petiole. 



457. The Filament, although usually slender and stalk-like, 

 assumes a great variety of forms : it is sometimes dilated so as 

 to resemble a petal, except by its bearing an anther ; as in the 

 transition states between the true petals and stamens of Nym- 

 phsea, shown in Fig. 318. 



458. Such petaloid filaments would indicate that this part of 

 the stamen answered to blade rather than to footstalk, whib 

 others would harmonize better with what seems at first sight to 

 be the more natural view, that the filament is the homologue of 

 the petiole, the anther of the blade of a leaf. Remembering 

 that in large numbers of leaves there is no distinction into petiole 

 and lamina or blade, such homologies should not be insisted on. 

 The filament ma}' be variously appendaged by outgrowths. Some 

 of these appendages are very conspicuous, such as the scale of 

 Larrea (Fig. 405), which is on the inside, and the nectariferous 

 hood of Asclepias on the outside ; or there may be a tooth on 

 each margin, as in species of Allium. 



459. The Anther, the essential organ of the stamen, contain- 

 ing the pollen, surmounts the filament, when that is present. 

 It normally consists of two cells or lobes, the word cell being 

 here used in the sense of sac. But, as each sac is not rarely 

 divided into two cavities (locelli), the best technical name for 

 anther-sac is that of THECA. The two thecse, lobes, or cells are 

 commonly connected by a more or less evident and sometimes 

 conspicuous common base or junction, which is mostly a pro- 

 longation of the filament, the CONNECTIVUM, or in English 

 CONNECTIVE. 



460. For the discharge of the pollen, the cells of a normal 

 anther open at the proper time by a line or chink, usually 



