160 Mr. J. Miers on the Bignoniacese. 



no such replum becomes manifested, as might be expected ; nor 

 does it exist among other genera of the Catalpea, the Incarvillea, 

 or the Eca^emocarpeae. This replum, which results from the 

 union of the adjacent midribs of the conjoined carpels, though 

 simple in Pithecoctenium and Amphilophium, splits into two in 

 most of the genera. 



In the second subtribe, the Catalpea, the seeds are not affixed 

 near the edges of the valves, as in the preceding group, but close 

 to a line down their middle, where they are attached to the margins 

 of the narrow transverse dissepiment ; the latter is at first united 

 to the valves, but it afterwards separates from them, bearing upon 

 each face a single series of seeds placed alternately on the right 

 and left. The same occurs in Argylia, where the seeds are 

 attached in that manner — not along its median line, as in- 

 correctly represented in Endlicher's ' Iconographia,^ tab. 71. It 

 sometimes happens in this group that a septiform extension of 

 the dissepiment takes place nearly across the cellular spaces, so 

 that the capsule becomes apparently 4-celled ; this occurs in 

 Sparattosper7na, Spnthodea, and Hete?'ophrag7na, where the cruci- 

 form dissepiments thus formed are greatly thickened, and occupy 

 nearly the whole capacity of the valvular spaces. It is well to 

 observe that in these cases the two longer arms of the cruciform 

 dissepiment terminate at the sutural commissures of the capsule, 

 the two shorter ones in the middle of the valves, and that the 

 seeds are borne by the latter : the ovary, at an early stage, is 

 bilocular, when the dissepiment, which is transverse, appears 

 much swollen in the axis, where it is not ovuligerous, but the 

 ovules are affixed on each side of the axial line : it is this barren 

 axial portion that subsequently extends in a cruciform direction, 

 ultimately reaching the commissures of the valves. These indi- 

 cations are of use as leading to a knowledge of the normal 

 structure. In Stereospermum a cui'ious but analogous increment 

 takes place : the ovary is 2-locular, with a thin dissepiment, and 

 with numerous ovules remotely placed in distinct series ; the 

 capsule is cylindrical, veiy elongated, 2-valved, the central space 

 being now filled up with a solid plug of a cork-like substance, 

 in transversely articulated, separable, vertebra-like sections, in 

 each of which a single seed is imbedded, attached by its hilum 

 to the bottom of its foveolar nest, with its two wings extend- 

 ing upwards and downwards rectangularly along the inner 

 face of the valves : these seminiferous cavities are placed alter- 

 nately in the middle of the four quarters, indicated by four nar- 

 row longitudinal cicatrices that run down the entire plug, show- 

 ing the lines of its attachment to the middle of the two valves, 

 and where it has touched their sutural margins. It would seem 

 that a very analogous structure exists in Parmeniiera. 



