f\ ` 562 MR. J. PARKIN ON THE 
^ T d 
079 
flowers originating in this way are to be found in the Papilionacez 
(Ononis, Vicia). The original raceme in these instances is reduced 
to the lowest flower, which is not strictly in the axil of the foliage 
leaf, but appears so, as the main axis of the original inflorescence 
has been suppressed. 
Regarding interealary inflorescences :— 
(10) Examples of interealary inflorescences are furnished by Drimys ; 
Choisya, Boronia; Calluna, Kalmia ; and especially by some of the Australian 
M yrtacem, such as Callistemon and Metrosideros. This type of inflorescence 
is capable of giving rise to another kind through the vegetative continuation 
aborting. An apparently terminal inflorescence will then be formed. In 
some species of Drimys this seems to have happened. Consequently, it is 
suggested that some apparently terminal inflorescences may, in reality, have 
originated from intercalary ones. The name pseudoterminal is therefore 
introduced for such. A raceme, for example, using the term in the strictly 
descriptive sense, can thus arise in two different ways, either from a pleio- 
chasium (panicle) or from an interealary inflorescence: the flower-cluster 
formed in the one way will not be precisely homologous with that produced 
in the other. 
EXPLANATION OF PLATE 18. 
The plate represents in graphic form the main ideas expressed in the paper, regarding the 
evolution of inflorescences from the solitary terminal flower, Commencing from fig. 1, which 
represents a shoot bearing a solitary terminal flower, the arrows indicate the lines of evolution. 
On the left side the evolution of eymose and racemose inflorescences, as well as of two types 
of the solitary axillary flower, is shown. On the right side the manner in which intercalary 
and pseudoterminal inflorescences, as well as a third type of the solitary axillary flower, 
arise, is depicted. 
Symbols used :— 
" = flower. 
> =foliage leaf. 
= — bract (non-foliaceous leaf ). 
( = vegetative bud. 
— climbing stem. 
The numbers 1, 2, 3, etc., show the order in which the individual flowers c si 
poy 5 , omposing 
an inflorescence, open. 
