Campanulatce. 293 
of this activity by the extreme variability of the relative position of 
the ovary within undoubtedly close circles of affinity, even within 
the same genus ( Saxifraga ). The character in question offers an 
excellent example of the differing critical value of a single character 
in different groups and for different purposes: in Rosaceae epigyny 
may serve only to distinguish one species from another ; in the higher 
Sympetalas it may be of cohortal value. In any case the value of 
any given character can only be judged in relation to the history in 
descent of the groups to which it is to be applied as a criterion. 
Origin and Affinities of Campanulatce. From the plexus of 
polypetalous groups in which the tendency to epigyny is clearly 
traceable we have recognised already the emergence of one line,— 
that leading to Utnbelliflorae, and so indirectly to Rubiales. We 
are now dealing with a distinct line, leading to the Campanal 
Stock, determined by sympetaly and by the pollen-presentation 
tendency; the line is distinct from the rubialian fundamentally, 
namely, in the last-named tendency, and in the character of the 
inflorescence. 
The Campanal Stock will thus he defined as including hemi- 
epigynous and epigynous forms, with anthers in various stages of 
approximation ; the ovary, like that typical of Rosales, will be 
multilocular and multiovulate. In the Rosales the androecium is 
usually in two whorls, hut there are no representatives of this con¬ 
dition among their sympetalous derivatives 1 ; we are, in fact, 
confronted with the same lack ot transitional (heteromerous) forms 
in this regard as in the case of Contortae (chapter IV). The 
existing group which approximates most nearly to the Campanal 
Stock as we have defined it, is the tribe Campanuloideae of Cam- 
panulaceae, which includes mostly forms with regular corollas. 
But the tendency to zygomorphy in the individual flower is trace¬ 
able in a closely continuous series of forms among Campanuloideae* 
Cyphioideae and Lobelioideae ; and this tendency is one of the two 
which determine two evolutionary lines leading from the Campanal 
Stock (see diagram in the preceding chapter, p. 230). The line 
in question terminates with Goodeniaceae, characterized by the 
presence of a special cup or indusium formed about the stigma for 
the purpose of collecting the pollen and so facilitating its presenta¬ 
tion ; ” this indusium is foreshadowed in the definite rings of hairs 
occurring below the stigma in some Campanulaceas. As a diver¬ 
gent offshoot from this line stand the Candolleacece, in which the 
See, however, the remarks on Vaccinioidete, infra p. 300. 
1 
