indvding a new Arrangement of Phanerogamous Plants. 459 



nigra carpels posterior are very rare, even if the apparently pos- 

 terior carpels are really so ; but Broussonetia and Ficus show a 

 decided contrariety in the position of the fertile carpel, although 

 it is much less frequently posterior than in any other direction ; 

 perhaps not more frequently so than in some species of Acacia^ 

 UfiTiCACEiE. In Parietaria officinalis the stigma is entirely 

 unilateral and always curves away from the axil ; the posterior 

 side of the ovary is rather less curved, and there are appearances 

 of a faintly marked suture (PI. XV. fig, 23). The ovary of Ur- 

 tica urens has the stigma sessile, but the ovary is always more 

 curved on one side, which proves to be always the anterior ; it is 

 probable therefore that Urtica corresponds with Parietaria in the 

 position of the carpel. 



CANNABiNEiE. The axis is here (as it frequently is in two- 

 flowered axils) compound, as Mr. Brown has termed it, that is, 

 the two flowers are to be understood as springing from a central 

 axillary bud which remains undeveloped. Thus, in Cannabis, the 

 axils of the bracts are two-flowered from the suppression of the 

 central bud, which sometimes developes as a leaf-bud, and gives 

 origin to a short branch, and the two stigmas in each flower are 

 anterior and posterior to the central point of the axil. The seed 

 is pendulous with a superior radicle, which is always on the ex- 

 ternal side of the ovary directly away from the axil laterally, the 

 cotyledons being on the axillary side. In its early stages the 

 ovule appears to be pendulous from the apex of the cell, but in 

 the ripened seed its attachment inclines distinctly to the posterior 

 side, though less so than in Humulus. On the internal side of 

 the ovary (that is, next the central point of the axil) a thickened 

 rib somewhat grooved extends from the attachment of the ovule 

 to its base, which, considering also the position of the radicle and 

 cotyledons, is doubtless the placenta ; this rib appears as if con- 

 sisting of two columns, whereas the rib on the opposite or exter- 

 nal side of the ovary is single and acuminated ; and each of 

 them is opposite a stigma, the ovary being otherwise merely 

 membranous (PI . XV. fig. 24) . The structure of the ovary, there- 

 fore, is the same as that of Elatostemma and Morus, and, taken 

 in connexion with the position of the cotyledons and radicle, 

 leaves no doubt that the fertile carpel is always anterior. 



In the two-flowered axils of Humulus the same relations are 

 maintained as in Cannabis, and when the flowers are increased to 

 three or four, the developed carpel is still always on the flattened 

 side of the bractlet or sepal infolding the ovary, the margin of 

 which in the two first flowers is external or away from the axil, 

 so that it has the same relation to the one-sided bractlet. The 

 ovule is pendulous, not precisely from the apex but rather from 



30* 



