544 MR, J. PARKIN ON THE 
(5) Campanula garganica. 
The flower-arrangement in this species may be derived from one like 
C. isophylla, which shows very little foliar reduction in the leaves, which 
subtend the secondary flowers. By lengthening the main axis of the in- 
florescence and by increasing the number of laterals, a flower-arrangement 
like that in C. garganica is reached. In this species the terminal flower 
bleoms first, and then the laterals—five to six or more in number—open in 
the ascending order. The bracts and bracteoles as well retain their foliar 
character. Tertiary flower-buds are produced to a small extent. The plant 
is a trailer. Accentuate this habit and the terminal flower would most likely 
cease to bloom first, then tend to be arrested in its development, and finally 
never appear. The flowers would now arise acropetally in the axils of the 
foliage leaves and become in systematic terminology solitary and axillary, 
provided the tertiary flowers were totally suppressed. 
This, however, is a digression, as the origin of solitary axillary flowers 
according to this fashion is fully dealt with in a succeeding section of this 
paper. 
The genus Campanula exhibits a. further advancement than that shown in 
the production of loose inflorescences, largely racemose in character. The 
flowers, for instance, are clustered to form a dense spike in C. thyrsoides 
and a head in C. glomerata. In two other genera of the Campanulacee, 
Phyteuma and Jasione, compact spikes and heads become the rule. 
It is interesting to note that in the Lobeliaceze (now considered a subfamily 
of the Campanulacex), the more advanced floral structure is associated with 
a more detinite racemose inflorescence, the terminal flower being absent and 
tertiary flowers rare ; whereas in the Campanulaces in the siricter sense, 
the terminal flower is often present and tertiary flowering axes common. 
In the large and widely spread family, the Composite, which terminates, 
as it were, a sub-group of the Sympetalze, commenced by the Campanulacere, 
the head or capitulum has become the uniform style of inflorescence through- 
out. Further evolution has shown itself, both in differentiating between the 
flowers (florets) composing this compact form of cluster, and in grouping the 
heads together to form compound inflorescences. 
In the majority of the Composite, in fact, the individual head has largely 
come to function as a single flower, and in many of the radiate forms the 
likeness to such is very marked, especially so when the ray and tubular 
florets are few in number and the former wide and petal-like. 
It is interesting to note that the clustering together of the heads in the 
Composite advances in a similar fashion to that which has been shown for 
individual flowers. Solitary heads give place to simple cymose clusters, then 
follow groupings more or less racemose in character, culminating in compound 
