126 CRUCIFER.t:. 



The peculiarity of the stamens gave the name and character to the class, 

 Telradynamia, which in his Artificial System Linnaeus framed for the recep- 

 tion of these plants. Of the six stamens, two are shorter and inserted one 

 opposite each lateral sepal ; while the four longer, which are commonly in- 

 serted a little higher on the receptacle or hypogynous disk, are placed one 

 pair before the posterior, and the other before the anterior sepal. This 

 brings them partly before the four petals respectively ; which has not unnat- 

 urally been taken to be their normal position by several botanists, as by 

 Kunth,* and Gay,f who thus view them as forming the complete inner 

 stamineal verticel, and consequently suppose that half of the exterior verticel 

 (namely, the two stamens which should stand before the anterior and poste- 

 rior sepals respectively) has been suppressed. But it is plain, as our dia- 

 grams (Plates 53, 54, 63, &c.) show, that these four stamens are not oppo- 

 site the petals. As already remarked, they stand in pairs before the anterior 

 and posterior sepals, or alternate, with the two upper and two lower petals, 

 that is to say, just in the places which should be occupied by single stamens 

 to complete the symmetry of the tetramerous flower. In other words, the 

 anterior and posterior stamens of the simple verticel are doubled, just as the 

 two stamens of Fumariaceae are trebled, by deduplication. 



This explanation, as applied to Fumariaceae, was in type, as it now stands 

 (on page 118), when, just in the nick of time, I received the London Jour- 

 nal of Botany, for January, 1848, containing a beautiful elucidation of the 

 Structure of Cruciferous Floicers, by Prof. Moquin-Tandon and my friend 

 P. Barker Webb, in which this view is brought forward and enforced in a 

 much more thorough and convincing manner than. I could have hoped to do- 

 it. % To the instances cited by them in which one or both of these stamens 



* L'bcr die Blilthen- vnd Fruchllildung dcr Cruciferen, in Abhandl. Konigl. 

 Mad. lilssensch. Bcrl. 1832. 



t In Ann. Sci. JVat. Oct. 1842. p. 218. 



t "De Candolle, himself, has shown in his Memoir on Crucifera, that each 

 pair of geminate stamens has really only the value of a single organ, and con- 

 sequently that the andrceceum in Cruciferae may, like the corolla and calyx, be 

 reduced to the quaternary type." 



" This theory of the didoubhment of the two longer stamens in this group is 

 confirmed by numerous facts, both normal and anomalous. 1. In many Cru- 

 ciferee, and more particularly in the Clypeola cyclodontea, Del., the filaments of 

 the solitary stamen are furnished with two teeth, one on each side, whilst those 

 of the double stamens have but one on their outer side ; if we join these two 

 stamens together, so that they form but one, a bidentate filament will result en- 

 tirely similar to those of the solitary stamens. 



" 2. In other Cruciferffi a longer or shorter portion of the filament remains 

 simple. Thus, in the Sterigma tomentosum, DC, the division takes place as 

 tar as the middle; in the Anchonium Billardieri, DC, in a third part only of 

 the upper portion of the filament. Here the position of the longer stamens, 

 double only in their upper portion, is exactly the same as that of the solitary 

 stamens. 



" 3. In the Vella psendocytisus, Linn., we find, in the place of the double sta- 

 mens, a single one: its filament being frequently rather broader, sometimes di- 

 vided only at its summit, sometimes entirely undivided, but bearing in that case 

 an anther, wholly or partially geminate. 



"4. Many Crucifcrae become tetrandrous by pclorization, others are normally 

 so. In either case, the four stamens are then equal. 



