ation of pollen. On the other hand, in
cases like those of the common houseleek, where we meet with petaloid
organs combining the attributes of anthers and of carpels, we find the
inner layers devoted to the production of pollen, the outer to the
formation of ovules.

That the pollen-lobes are not to be taken as halves of a staminal leaf,
but rather as specialised portions of it, not necessarily occupying half
its surface, is shown also in the case of double-flowered _Malvaceae_, in
which the stamens are frequently partly petal-like, partly divided into
numerous separate filaments, each bearing a one-, or it may be even a
two-lobed anther. This circumstance is confirmatory of the opinion held
by Payer, Duchartre, Dickson, and other organogenists, as to the
compound nature of the stamens in these plants. The stamens are here
analogues not of a simple entire leaf, but of a lobed, digitate, or
compound leaf, each subdivision bearing its separate anther. On this
subject the reader may consult M. Mueller's paper on the anther of
_Jatropha Pohliana_, _&c._, referred to at page 255.

[310] See C. Morren, "On Spur-shaped Nectarines," &c., 'Ann. Nat.
Hist.,' March, 1841, p. 1. tab. 11.

[311] Karsten, 'Flor. Columb. Spec.,' tab. xxix.

[312] See Dickson, "On Diplostemonous Flowers," 'Trans. Bot. Soc.
Edin.,' vol. viii, p. 100; and on the Androecium of _Mentzelia_,
_&c_., in Seemann's 'Journal of Botany,' vol. iii, p. 209, and vol. iv
(1866) p. 273 (_Potentilla_, _&c._).

[313] See Baillon, 'Adansonia,' iii, p. 351, tab. 12, _Sinapis_.

[314] 'Bull. Acad. Belg.,' xvii, part i, p. 516, c. tab., and
'_Lobelia_,' p. 83.

[315] Cited in 'Bull. Soc. Bot. France,' xiv, p. 253 ('Rev. Bibl.').

[316] 'Bull. Soc. Bot. Fr.,' 1858, p. 331.

[317] 'Mem. Legum.,' p. 44.

[318] 'Bildungsabweich, 'Pflanz. Fam.,' tab. 8, f. 12.

[319] 'Atlas de Goethe' p. 55, t. 4, f. 18.

[320] Wiegmann, 'Bot. Zeit.,' 1831, p. 5, tab. i.

[321] 'Ic. Flor. Germ.,' xiii, tab. 112, cccclxiv, f. 2.

[322] Seemann's 'Journal of Botany,' 1867, p. 317, t. 72, A (_Ophrys_).

[323] 'Enum. Euphorb.' p. 53.

[324] 'Linnaea.' i, p. 457.

[325] 'De Balsam,' p. 17.

[326] B. Clarke, 'Arrangement of Phaenog. Plants,' p. 23.

[327] See 'Engelmann,' p. 26, tab. 3, f. 10, 11, 14.

[328] 'Ann. Sc. Nat.,' ser. 2, t. viii, 1837, p. 58.

[329] 'Bot. Zeit.,' 4, 1846, 889.

[330] 'Verhandl. Nat. Hist. Ver. Preuss. Rheinl. und Westph.,' 1858,
1860, p. 381. C