33 
Notes on the Corolla in the Compositce. 
Conclusion and Summary. 
The characters of the corolla in the Eupatorieae and Vernonieae, 
although they do not confirm to any extent the inversion suggested 
in the position of these tribes, are quite in harmony with the change 
suggested by the study of the pollen-presentation mechanism. The 
corolla characters in whole or in part confirm the suggested lines 
of development for the Astereas, Inuleae, Cichorieae, Mutisieae and 
Cynareae. 
The interpretation of the ray floret as bilabiate and of the 
same type as the Mutisieae is confirmed by the form in abnormal 
florets and by the floral development. The position of the Mutisieae 
below the Cynareae is justified still further by this breaking down 
of the distinction between the florets of that tribe and the ray 
florets in others; it is also proved to be natural by the scarcity of 
blue and predominance of yellow flowers in this group as 
compared with the Cynareae. The development of an irritable 
pollen-presentation mechanism, as shown in the Arctotideae, 
Mutisieae and Cynareae (13,15,|17, 20,28,30) also supports the change, 
but that is the subject of a special enquiry. 
It is suggested that the Cichorieae arose from the Senecioneae 
by mutation, and evidence in support of the hypothesis is adduced 
from the published accounts of mutations in the order. Describing 
a mutation in Senecio vulgaris in the ray florets of which “instead of 
being obscurely three-toothed at the tip, the ligules were often divided 
down to the basal tubular portion into three (sometimes two) long, 
narrow segments,” Trow (31) states that “it is clear that the 
fimbriate character is inherited, and it may be assumed that a 
corresponding factor, F, suddenly dropped out of the constitution 
of the original plant.” The hypothesis is that a factor similar to, 
but distinct from, this fimbriate factor acted to produce the 
Liguliflorae. In this way the great similarity even in the most 
unimportant details throughout this sub-order can be explained, for 
if the group is monophyletic and of recent origin, it is obvious that 
it will not have had time to produce forms differing to the degree 
which obtains in the other tribes of the Compositae. The fact 
that no intermediate types are found, although negative evidence 
and therefore not particularly reliable, also supports the view that 
the Cichorieae arose by a sudden variation, which has not been 
repeated except, perhaps, in Scolymus. 
There are several groups of data which are of phylogenetic 
importance and these will be considered later. The occurrence and 
