150 Linnean Society. [June 17, 



5. The character of ovule erect, with the raphe lateral (first ob- 

 served by Mr. Bennett in Rhamnece, and by him attributed to a torsion 

 of the funiculus), obtains to a considerable extent among Exogenous 

 families. It occurs regularly in Stilbe pinastra, and generally in 

 one-seeded fruits of Berberis vulgaris ; but in two-seeded fruits of 

 the latter the raphe is removed from the placenta and placed nearer 

 to the dorsal rib of the ovary. In Vitis, on the contrary, whether 

 with one- or two-seeded cells, the raphe is always next the placenta. 

 In a species of Justicia, with two ovules, placed one above the other 

 and quite erect, the raphe is lateral ; but in Mendozia, with a similar 

 placentation, it is apparently next the axis. As other instances of 

 lateral raphe with erect ovules Mr. Clarke cites Elceagnus orientalis. 

 Calamus viminalis, and Trianthema decandra, the direction of the cur- 

 vature in the embryo of the latter being regarded as analogous to 

 the position of the raphe in the two former. 



6. The position of the raphe next the placenta is well known to 

 be the ordinary condition in erect anatropal ovules, and on this head 

 the author enters into no details. 



Mr. Clarke then proceeds to consider the causes by which these 

 differences in the position of the raphe may be produced. 



1 . He adopts the opinion (first demonstrated by Mr. Brown) that 

 a single ovule pendulous with raphe aversa is the result of an erect 

 ovule pressed or growing downwards from the elongation of the 

 cavity of the ovarium in that direction, while its upper part remains 

 stationary ; but suggests that it is only when an erect ovule has the 

 raphe properly next the placenta that it has raphe aversa, when it 

 thus becomes pendulous. And looking to their afiinities, he thinks 

 it not improbable that all pendulous orthctropal ovules shovJd be 

 referred to the same cause. 



2. He believes that a single pendulous ovule with the raphe lateral 

 is an ovule originally extending horizontally from the placenta with 

 the raphe lateral, as in Ranuncnlaceee and Cucurbitacece, and sub- 

 sequently pressed downwards as in the former case. 



3. He maintains that a single pendulous ovule with the raphe next 

 the placenta is the only true pendulous ovule, with the exception of 

 pendulous campylotropal and amphitropal ovules with the foramen 

 (and subsequently the radicle of the embryo) turned away from the 

 placenta. 



4. He conceives that one or two erect ovules vrith the raphe turned 

 away or obliquely away from the placenta result from pendulous 

 ovules pressed upwards by the elongation upwards of the cavity of 

 the ovarium ; and adduces in support of this opinion the pendulous 



