384 OBSERVATIONS ON PLANTS 



the original formation of the petal. To establish these 

 points, and consequently to prove that the parts in question 

 are simple petals, and neither made up of two cohering 

 envelopes, as M. Tristan supposes, nor of a calyx and abor- 

 tive stamina, according to Mr. Lindley's hypothesis, I shall 

 describe their gradual development, as I have observed it 

 in the common Mignonette, a plant in which all the 

 anomalies that have led to this hypothesis exist in a very 

 great degree. 



The flower-bud of Reseda odorata, when it first becomes 

 visible, has the divisions of its calyx slightly imbricate and 

 entirely enclosing the other parts. In this stage the unguis 

 of each of the two upper petals is extremely short, not 

 broader than the base of the lamina, and is perfectly simple ; 

 there being no rudiment of the inner process so remarkable 

 in the fully expanded flower. The lamina at the same 

 period may be termed palmato-pinnatifid, its divisions are 

 all in the same plane, the terminating or middle segment is 

 whitish or opaque, and several times longer than the lateral 

 segments, which are semi-transparent. 

 S30] Of the remaining four petals, the two middle are 

 dimidiato-pinnatifid, their lateral segments existing only on 

 the upper side ; and the two lower are undivided, being 

 reduced to the middle segment or simple lamina. All the 

 petals are erect, and do not cover the stamina in the slightest 

 degree, either in this or in any other stage. The disk is 

 hardly visible. The antherse are longer than their fila- 

 ments, of a pale-green colour ; those on the upper or pos- 

 terior side of the flower being manifestly larger, and slightly 

 tinged with brown. The pistillum is very minute and 

 open at the top. In the next stage the calyx is no longer 

 imbricate, but open ; the petals have their segments in 

 nearly the same relative proportions ; the interior margin of 

 the unguis is just visible; but the transition from unguis 

 to lamina is still imperceptible ; the apex of the former not 

 being broader than the base of the latter. It is unneces- 

 sary to follow the development through the more advanced 

 stages of the flower, the facts already stated being, in my 

 opinion, absolutely conclusive as to the real nature of the 



