ANGIOSPERMS. 



543 



assumed, until more exact observations bring something different to light, that each 

 pollen-sac {i.e. each loculus with its wall) corresponds to a sporangium, and hence 

 also to a single pollen-sac of Cycadeae and Cupressineae ; and that therefore the 

 anther usually consists of four pollen-sacs springing side by side from the anterior or 

 posterior side of a staminal leaf, the sacs lying in pairs so close to one another 

 right and left of the connective, that they coalesce more or less laterally to form one 

 anther-lobe. But before we pass on to the consideration of the pollen-sacs and 

 their contents, we must again recur to the discussion of the entire stamen and 

 androecium. 



The stalk of the anther (the filament with its connective) is either simple or 

 segmented. The simple filament may be filiform (Fig. 359) or expanded into the 

 form of a leaf (Fig. 358), sometimes even very broad, as in Asclepiadeae and 

 Apocynacese; or it may be broad below (Fig. 363,/) or above; it generally termi- 

 nates between the two anther-lobes, but is not unfrequently prolonged above 

 them (Fig. 358, B) as a projection, or in the form of a long appendage as in the 

 Oleander. If the upper part of the stalk, the connective, is broad, the two anther- 



FlG. 362. — Stamen o{ Mahonia Aqiti- 

 Jfllinm ; B with the anther open (by re- 

 curved valves). 



Fig. 363. — Stamen oi Arbiitits hybrida, 

 antlier open (by pores) ; x appendage. 



Fig. 364. — Stamens of Centj-adenia 

 rosea ; A a larger fertile one, B a smaller 

 sterile one of the same flower. 



lobes are distinctly separated (Figs. 358, 362); if it is narrow, they lie close to one 

 another. The articulation of the stalk is very commonly the result of the con- 

 nective being sharply separated from the filament by a deep constriction; the 

 connection of the two is then maintained by so thin a piece that the anther, together 

 with the connective which unites the anther-lobes, swings very lightly as a whole on 

 the filament (versatile anther). The point of connection may be at the lower end, at 

 the centre (Fig. 363), or at the upper part of the connective; sometimes the detached 

 connective attains a considerable size, and forms appendages beyond the anther 

 (Fig. 364, A, x), or it is developed between the two lobes like a cross-bar, so that 

 the filament and connective form a T, as in the Lime, and to a much greater extent 

 in Salvia, where the transversely extended connective bears an anther-lobe on one 

 arm only, while the other is sterile and is adapted for a different purpose. Whether 

 the anther-lobes are parallel depends on the mode of their connection with the 

 connective ; if they are so, they are usually attached to the connective for their 

 whole length ; or in other cases they are separated above, or free below and 

 coherent above, in which case they may become placed at such a distance from one 



