ON SOME BICARPELLARY BEANS, 17 
Some Bicarpellary Beans, 
By Eric Drank, D.Se., F. L.S. 
[Read 21st January, 1904.] 
Dvnrwa the autumn of 1903 an interesting series of fruits of 
the French Bean, Phaseolus vulgaris, Savi, was obtained from 
a garden on the clay of the Middle Coal-measures of North 
Derbyshire. These beans were bicarpellary in nature, but the 
degree of development attained by the second carpel varied 
considerably. In the simplest case (fig. 1) it was present merely 
Fig. 1. 
A 
È 
i 
A 
as a small pod on the posterior aspect of the normal carpel, and 
adhered to the latter in its lower portion in such a way that a 
bilocular ovary was formed. The posterior carpel was without 
seeds. 
In other cases (figs. 2 & 3) the posterior carpel was more 
extensively developed, and the basal fusion with its anterior 
fellow resulted, not, as in the last case, in a bilocular ovary, but 
in a unilocular one. Distally the two carpels were free from 
one another. - 
In the bean shown in fig. 4 the same sort of structure 
was attained, but the posterior carpel was as large as the 
anterior one and bore one or more well-formed seeds. The 
distal extremities of the carpels were free and divaricated widely, 
recalling somewhat the kind of ovary met with in the Saxifrages. 
A particularly striking fruit was that shown in fig. 5. Here 
the midrib of the posterior carpel was normally developed in the 
distal region, but more proximally it was greatly reduced, and 
passed gradually towards one of the lateral sutures of the fruit. 
LINN. JOURN.—- BOTANY, VOL. XXXVIT. C 
