298 H. F. Wernham. 
pollen-presentation; but no such phenomenon is to he associated 
with cucurbitaceous flowers. The diclinism of the latter, and, 
more important still, the regularly extrorse dehiscence of their 
anther-sacs, are of essential significance in this connection; for this 
type of dehiscence is altogether inconsistent with pollen-presentation. 
Again, the spuriously septate ovary of Cucurbitaceae, with placen- 
tation that is, strictly speaking, parietal, offers no legitimate com¬ 
parison with the ovary of Campanulas, which is primarily septate, 
from the aspect of both ontogeny and phylogeny. 
Indeed, it would seem that Cucurbitaceae have no near relations 
among Sympetalae; truly the nearest resemblance is displayed by 
the Campanulatae—a resemblance which we have just found reason 
to suspect of being little more than merely superficial. But their 
affinities with Archichlamydeae are not far to seek,—namely, in the 
epigynous groups of Engler’s Parietales, the Passiflorales of 
Bentham and Hooker. Here is to be found a strong tendency to 
separation of the sexes (Begoniaceae, Datiscaceae, some Passi- 
floraceae), to union of the stamens, and to spurious septation of the 
ovary by the projection of placentae. The climbing habit, moreover, 
is a feature widespread among these groups. 
Considered as a sympetalous group, Cucurbitaceae seem to have 
more in common with Passiflorales than has any other group of 
Sympetalae with any other group of Archichlamydeae, and it would 
appear to be to the credit of the older systems that this affinity 
is recognized therein, in spite of the sharp line which is the custom 
to draw between the sympetalous and the polypetalous series. 
Whether, in effect, they be viewed from the aspect of a mere 
aggregate of characters irrespective of any guiding principle in the 
estimate of the value of those characters, or whether some sort of 
biological criterion be applied, as throughout these chapters, Cucur¬ 
bitaceae would appear to offer a striking example of the phyletic 
continuity which subsists between Archichlamydeae and Sympetalae; 
and this by reason of their similarity in essentials to the Passi¬ 
florales. Significant in this connection is the isomery of the 
stamens with the corolla in the extensive family Passifloraceae—a 
condition rare among Archichlamydeae. Sympetalous forms, more¬ 
over, are to be found among Passiflorales, apart from Cucurbitaceae 
— e.g., in Loasaceae and Caricaceae. The latter family, included by 
Bentham and Hooker in Passifloreae, comprises about thirty species, 
all characterized by a sympetalous, tubular corolla ; unlike Cucur¬ 
bitaceae, nevertheless, they are retained among Archichlamydeae in 
Engler’s system. 
