I 
118 H.F. Wernham . 
In a similar way we may observe the reflection in the Sympetalse 
of the various stages in the evolutionary advance of the gynsecium, 
as we have traced it in the Archichlamydeae—in the number of 
carpels, loculi, and ovules, and in the position of the ovary relatively 
to the rest of the flower. 
The consequence of all this is, that there is a prima facie 
presumption that the Sympetalae are polyphyletic in origin,—unless, 
of course, it he supposed that they arose from pro-angiospermous 
ancestors quite independently of the Archichlamydeae, a supposition 
which seems to be contrary to all scientific principle. We shall 
have occasion to return to this matter after we have dealt with the 
Sympetalag in some detail; in the meantime, we make the reasonable 
assumption that the latter group are the direct descendants of 
Archichlamydeous ancestors. 
In spite of the possibility that the Sympetalag form a polyphyletic 
series, this series is synthetic in so far that its component members 
may be connected on the lines of certain well-marked progressive 
tendencies to biological advance. 
These tendencies we proceed to trace, in relation to the 
classification of the group. They do not differ, fundamentally, in 
any way from the tendencies which we have observed at work in 
the Archichlamydeag ; but they differ in degree, as is to be expected, 
in view of the relatively high biological organization of the group. 
The tendency to oligomery has reached an advanced stage of 
realization, so that it plays but a secondary role in the Sympetalag; 
it is the second fundamental principle, that of progressive adaptation 
to insect-visits, which is prominent. This fact emerges as we study 
the classification of the Sympetalag exhibited upon the following 
page; the relations between the two modern accepted systems, 
those of Bentham and Hooker, and of Engler, are approximately 
indicated. With this latter purpose in view, the natural orders of 
the last cohort, Campanulas, have been shewn at length. 
The merits and objections attaching to these systems will be 
discussed in the sequel; in the meantime, with the classification 
before us in tabular form, we may, in anticipation, draw attention 
to the following broad considerations:— 
Note. —re Table on next page. The arrangement of the cohorts in Engler’s 
System is that reproduced in Willis’ “Flowering Plants and Ferns,” second 
edition, 1904. Attention will be called subsequently to one or two minor changes which 
have since been made, 
