554 MR. J, PARKIN ON THE 
from the axils of foliage leaves in acropetal succession. The lateral 
(secondary ) flowering shoot bears two bracteoles, and from the axil of one 
of these a tertiary flower may arise. Thus flowers to this degree may be 
produced to some extent. ‘fhe main axis finally ends in a. terminal flower, 
which is the last, or almost the last, to expand. 
Dy an inerease in the number of lateral flowering shoots, thus postponing 
the production of the terminal flower until it never appears, and by the 
total suppression of tertiary flowers in the above species, a plant with 
solitary axillary flowers would be obtained. The genus Convolvulus contains 
such, and the foregoing suggests the way in which this flower-arrangement 
has been evolved. By eliminating the bracteoles as well as the tertiary 
flowers, the axillary nature of the solitary flower is accentuated. Calystegia 
septum has solitary axillary flowers, in which the pedicels are naked. The 
bracteoles may be considered, then, to have vanished in this species. 
(3) Solitary axillary flowers arising from reduced inflorescences. 
This third type of the solitary axillary flower, which has come to the 
author's notice, ean be derived by reduetion from the axillary inflorescence. 
An axillary inflorescence, further, can be traced back to a terminal 
inflorescence, in the same manner as the solitary axillary flower of the 
type A, already considered, can be to the solitary terminal flower. The 
inflorescences, instead. of being developed at the ends of the main upper 
primary shoots—the primitive fashion—come to arise on the lateral, lower 
shoots. By the complete suppression of the foliage leaves on these latter, 
the inflorescence will become axillary. 
Another mode of origin for an axillary inflorescence, probably more 
applicable than the foregoing to the examples mentioned below, is as follows. 
After a terminal raceme has evolved from a pleiochasium, further complexity 
can be brought about through the pushing out of lateral racemes from the 
leaf-axils just below the terminal raceme. If, now, the climbing habit be 
commenced, these axillary racemes will tend to develop before the apical 
one ; and eventually, on the new habit becoming firmly established, flowering: 
by means of axillary racemes will become the rule. This manner of evolution 
of the axillary inflorescence is depicted in Pl. 18. figs. 6 & 7. 
The examples below of this third type of axillary flower are taken from 
the Papilionaces. 
Ononis.—hree species of this genus, which have come to my notice, 
demonstrate the evolution by means of reduction of the solitary axillary 
flower from the axillary inflorescence. 
Ononis rotundifolia has three-flowered axillary racemes (fig. 8, A). The 
pedunele, after emitting the successive flowers, ends in a sterile process. 
No bracts or bracteoles are borne on the inflorescence. The presence of the 
