88 STAMENS. 



hypothetic fundamental type of leaf -structure. At the first glance it might be sup- 

 posed that the filament is a metamorphosed petiole, and the anther a metamorphosed 

 lamina. But these monstrous flowers seem to indicate that such is comparatively 

 rarely the case. Thus in the green stamens of Campanula Tracheliwm (figs. 213 1" 

 and 213 ") there are scattered everywhere over the green substance of the lamina 

 yellow excrescences and warts containing reduced pollen-cells, and occasionally 

 these occur fused together into actual portions of anthers; hence it may be inferred 

 that in this case the anther may be regarded as equivalent to a green lamina. But 

 far more frequently in such cases the pollen-producing tissue is found at the 6ase of 

 the lamina only, at the upper extremity of the leaf-stalk, where these two parts 

 articulate. From this we may conclude that in the majority of cases anthers corre- 

 spond to that portion of a leaf at which the stalk runs into the lamina. In such 

 stamens the lamina is entirely suppressed, or is represented by a continuation above 

 the pollen-producing region. 



A few forms of this continuation above the anther, which we regard as repre- 

 senting a leaf lamina, are illustrated in fig. 214. Figs. 214^ and 214 ^ show it as a 

 small shot-like grain, 214 ^ as a truncate cone, 214 * as a two-pronged fork, 214 ^' ^' '' 

 as a fiat, triangular scale, 214 ^ as a toothed, sword-shaped process, 214 ^' ^i> i^> ^^' " as 

 a curved membraneous scale, 214 ^' and 216 ^® as a coloured bladder for attracting 

 insects; and, finally, figs. 214^^ and 214^^ as a long, whip-like bristle. 



That the filament of the stamen, or at any rate its lower portion, corresponds to 

 a leaf -stalk seems so obvious, that it is hardly necessary to prove it by comparison 

 with monstrous ca.ses. Its name of filament indicates its character in a great 

 number of fiowers. Examples of these are Hemp, Hop, Wheat, Rye, Rice, Maize, 

 Flax, and many others. For many cases no doubt the term filament is unsuited, as, 

 for instance, in the thick, abbreviated stalks in the Violet and Bryony (figs. 214 * 

 and 214 ^). Similarly the filament may be strap-, spindle-, or club-shaped. The last 

 is the case in Thalictrwrn aquilegifolium, Bocconia, Sanguinaria, and Actoea 

 spicata (cf. figs. 214 ^^ and 214 ^*), and it has been observed that the stamens very 

 readily oscillate at the moment of liberation of pollen with the slightest breath of 

 air. Like the foliage-leaves of the Orange, the stalks of which are provided with 

 a peculiar joint, many Spurges and Labiates have hinged filaments {cf. figs. 214 ^** 

 and 214^^). These hinges are wonderfully fashioned in many species of Salvia, 

 reminding one of the articulation of the feet of insects; their importance in fertili- 

 zation will be described in a later chapter. In the Linden the filament forks 

 immediately below the anther (fig. 214 ^*), whilst in Corydalis it is band-like, and 

 divides into three (fig. 214 ^). In the Castor Oil Plant (Ricinus), and many other 

 Euphorbiacee, it is much divided and branched (fig. 214 2^). These divided filaments 

 are not to be confused with fused ones, for occasionally we find that the filaments of 

 adjacent stamens unite with one another into a ribbon or tube, as for instance in 

 Mallows, Papilionacese, and Polygalaceae (cf 214 ^°). 



Attached to the sheath of foliage-leaves curious appendages, the stipules, are 

 often found (cf vol. i. p. 596). In the case of stamens these are but rarely met 



