104 Oliver. — On the Structure , Development , 
any case the ordinal distinctions in this assemblage are by no 
means so well marked as in other groups of Dicotyledons. 
This applies to the small order Pedalineae, to which Trap ell a 
has been referred ; certain genera being included in it, rather 
from the difficulty of placing them elsewhere, than from 
any other reason. Professor Oliver, in referring our plant to 
Pedalineae, did so, not that it agreed with the more normal 
genera in all points of structure, but rather as an alternative 
to making it the type of a new Natural Order intermediate 
between Pedalineae and Myoporineae. 
Not only was such a course expedient, but it was also one 
that is justified by a careful investigation of adequate spirit- 
material and a renewed study of the morphology of its 
supposed allies. In the next few pages I shall try to show 
that Trap ell a — though differing widely from all known 
Pedalineae — may yet be traced back to the stock from which 
it may be conceived the true Pedalineae arose. 
Before entering on this matter, it will be well to consider 
what claims Trapella may have to be united to certain other 
Orders of Monopetalae. 
Gesneraceae must be considered as one of the possible 
homes for Trapella , since here alone in the Labiatiflorae do 
we find in addition to superior, also inferior and semi-inferior- 
ovaried forms. Our plant essentially differs in having a 
bilocular ovary with axile placentation and two ovules ; 
Gesneraceae, on the other hand, having a unilocular ovary 
with two parietal placentas and very numerous ovules. The 
appendaged seeds of such genera as A eschynanthus offer no 
possible homologies, the appendages in question being mere 
outgrowths of the testa. Gesneraceae, it must be remembered, 
belong essentially to the New- World— -the tribe of the 
Cyrtandreae alone (to which several Chinese genera belong) 
being Old-World. Trapella , if it were found necessary to 
refer it to Gesneraceae, would have its relationship through 
this latter tribe. 
From Scrophulariaceae, Trapella differs in its solitary seed, 
and in the small amount of endosperm which it contains. It 
