In all cases it is desirable to ascertain, if possible, what parts of the stamen are thus transformed. In some Petunias the filaments are unchanged, but in place of the anther is a small lamina, representing precisely the blade of an ordinary leaf. Sometimes the connective only is replaced by a leaf. One of the most interesting cases of this kind that has fallen under the writer's observation was in _Euphorbia geniculata_, in which, in addition to other changes mentioned under prolification of the inflorescence, some of the stamens were partly frondescent, half the anther being perfect, the other half leaf-like. Another filament bore just above the usual joint three leaflets, two lateral ones, somewhat conduplicate, and a third central one, half anther, half leaflet. [Illustration: FIG. 134.--Flower of a _Petunia_, opened to show the stamens partially replaced by stalked leaves.] In the case of frondescent flowers of _Tropaeolum majus_ the stamens are usually absent or atrophied, but in other instances the filament is present as usual, representing the stalk of the leaf, and surmounted by a small lamina, but this latter, in place of being nearly flat, is pinched up in the centre from back to front, and surmounted by a two-lobed anther, so that the general appearance of the whole structure is that of a central anther, supported at the base on each side by two concave leaf-lobes, or it might be compared with a three-lobed leaf, the terminal lobe represented by the anther. In _Jatropha Pohliana_, Muell. (_Adenorophium luxurians_, Pohl.), a singular condition has been observed by M. Mueller (Argov.). In this flower the anther, in place of being represented by the flat blade of a single leaf, had the appearance as if two such blades were present and coherent one with the other by their midribs, along their upper or inner surfaces, which were directed towards the centre of the flower (fig. 136), thus resembling the cases of adhesion of leaves by their surfaces already referred to (p. 33). In other cases, in the same plant, the anther appeared as if formed by two collateral leaves, the faces looking towards the circumference of the flower, and their margins so folded together as to represent an open anther lobe (fig. 135). These cases are apparently due, not to the formation and adhesion of two leaves, but rather to the exuberant development of one leaf into two blades.[261] The bearings of these and other similar malformations on the morphology of the anther are alluded to under the head of petalody of the anther. [Illustration: FIG. 135.--Phylloid anther of _Jatropha_, after Mueller (Arg.).] [Illustration: FIG. 136.--Leaf-like anther of _Jatropha Pohliana_, after Mueller.] Phyllody of the stamens has been most often observed in the following plants: