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H . F. Wernham\ 
doraceas Dobera and Azima have polypetalous corollas, and these 
represent some six species out of eight. We shall return to this 
point when we approach the question of the affinities of the group. 
The sympetalous corolla, then, is a character almost invariable for 
the Contortae. 
The stamens are nearly always epipetalous, the hypogynous 
arrangement occurring only in a few Oleaceae and in Salvadoraceae. 
There is little or no tendency either to aggregation into dense 
inflorescences or to zygomorphy; but there is a special tendency to 
gynandry in relation to insect-visits, observable in the Apocynaceae 
and culminating in the Asclepiadaceae. This gynandry is associated 
in the latter order with other specializations such as massing of its 
pollen, so that the floral complexity of the Asclepiads is comparable 
only with that found in the Orchids. 
Epigyny is practically non-existent among the Contortae, partial 
exceptions being afforded by a few Apocynaceae (e.g., Apocynum, 
Ichnocarpus, Epigynum ); in these the ovary is more or less sunk in 
the receptacle, in a manner comparable with the semi-inferiority 
found in the sapindalian Celastraceae. 
We have now to consider the question of the ancestry and 
affinities of this cohort, and we are met at the outset with a difficulty 
which did not present itself so formidably in the case of the Penta- 
cyclidae. This difficulty finds expression in the remarkable constancy 
of the essential floral characters throughout the group, and in the 
relatively advanced degree of those characters considered from the 
aspect of our two fundamental evolutionary principles. A gulf is 
thus discovered between the Contortae and the Archichlamydeae 
which at first sight seems difficult to bridge; for the combination of 
an isomerous alternating androecium with a bicarpellary and 
superior ovary is extremely rare in the latter series—the sole group 
in which this combination occurs at all to any extent being the 
highly evolved Umbelliflorae, in which the ovary is inferior. 
In the Archichlamydeae, however, we must contemplate the 
tendency to economy from the aspect of its progress rather than of 
its realization ; and the rarity of forms which have fully worked out 
this tendency before adopting sympetaly is scarcely matter for 
surprise. For the ancestry of the Contortae we must look for a 
group in which a tendency to isomery of the androecium is definitely 
traceable, together with a tendency to a bicarpellary gynaecium ; at 
the same time any tendency to epigyny must be absent, or practically 
absent. These conditions are satisfied by the stock represented in 
