io8 Oliver . — On the Structure , Development , 
The genera Martynia and Craniolaria deviate entirely from 
the type of Pedalineae, from which all the others can be 
derived. In them placentation is parietal ; and, as Baillon 
has pointed out, they may reasonably be removed from 
Pedalineae to be placed perhaps with Gesneraceae. Such a 
severance from Pedalineae is strengthened when we consider 
that these two genera alone are American — all other Pedalineae 
being Old-World. As above stated, Gesneraceae are, with the 
exception of the Cyrtandreae, which belong to both, also New- 
World. 
Passing on to Trapella itself. In it we find a genuinely 
axile placenta, and no trace of any tendency to develop false 
partitions. As in Rogeria , one loculus has become much 
reduced ; in Rogeria it is the posterior, in Trapella the 
anterior. This is to be regarded only as an instance of 
abortion of one ovary-cell arising independently in the same 
Natural Family, not as indicating a very close affinity between 
Trapella and Rogeria. Trapella , in its pendulous ovules and 
primarily bilocular ovary, approaches Pedalium. Even in its 
rudimentary loculus we find in Trapella what may very well 
be regarded as a rudimentary ovule (p. 82). The essential 
points of distinction depend perhaps upon its ovary being 
semi-inferior, for correlated with this, it may be, are all the 
peculiarities at issue. 
It is an important thing to notice that Pedalium is not 
limited to S. Africa, as are so many of the other genera. It 
is a native also of Eastern India, and this brings it into 
relation with Trapella , a native of Central China (Ichang) and 
Japan. Trapella , I believe, has originated from the Pedalium 
stock, and adapting itself to an aquatic mode of life, has 
become profoundly modified. The tendency of the ripening 
seed (only one of the two ovules ever develops into a seed) to 
elongate downwards may perhaps have been an important 
factor in the initiation of great floral changes. The ancestral 
superior ovary, it may be supposed, has become invaginated 
into the receptacle, and its extension, in a downward direction, 
very greatly increased to accommodate the enlarging seed. 
