664 TRANSACTIONS OF SECTION K. 
derived from a pleiochasium, in which the leaves on the main axis have 
remained largely foliaceous (unreduced). As the climbing habit evolves the 
flowers will tend to be developed acropetally rather than basipetally, and 
ultimately the terminal flower will never be produced, for the main axis 
will continue growing the whole season, throwing off lateral flowers succes- 
sively from each leaf-axil. These axillary flowers are probably, as a rule, 
reductions from lateral dichasia. Such an evolution for certain solitary 
axillary flowers has been suggested by a study of species of Clematis and 
Convolvulus. 
(B) A second variety of solitary axillary flower occurs in certain arbor- 
escent plants. It can be derived directly from the leafy shoot with a solitary 
terminal flower through the reduction and ultimate eliminatjon of the 
foliage, together with the shortening of the axis. There is a tendency in 
many trees and shrubs to transfer the flowers from the terminal and upper 
shoots to the lower lateral ones (Calycanthus, Rosa). By reducing such 
a subordinate shoot to merely the apical flower, a solitary axillary flower 
will result, provided the tree or shrub be evergreen (Michelia, Illiciwm) ; 
if, however, it be deciduous, then the flower will appear singly above the 
leaf-scar on the previous season’s growth (Asimina, Chimonanthus). 
Intercalary Inflorescences.—Attention was finally drawn to a kind of 
inflorescence which has so far received little consideration. It is charac- 
terised by the fact that the main axis, after emitting a number of flowers 
laterally, continues its apical growth vegetatively. The reproductive part 
of the axis is, therefore, as it were inserted between two vegetative portions. 
The author proposes the term intercalary for such a type of inflorescence. It 
seems capable of derivation from lateral shoots bearing terminal flowers by 
grouping these together and by reducing all the leaves to bracts. Examples 
of intercalary inflorescences are furnished by Drimys; Choisya, Boronia; 
Calluna, Kalmia; and especially by some of the Australian Myrtacee, 
such as Callistemon, Metrosideros. If the vegetative continuation of such 
an inflorescence be arrested, a false terminal one will be formed, as happens 
sometimes in Drimys. Consequently the author suggests that some 
apparently terminal inflorescences may in reality belong to the intercalary 
class (probably some Ericacee). 
2. The Prothallium and Embryo of Danea. 
By Professor Douaitas H. CampBeuu. 
In July 1908 a fine series of prothallia and young plants of Danea 
was secured in Jamaica. The greater number of specimens belonged to 
D. Jenmani, Underw., but there was a good series of D. elliptica, Sm. 
and a smaller number of specimens of D. jamaicensis, Underw. The latter 
were collected at Morce’s Gap; the others in the vicinity of Vinegar 
Hill, both stations being a few miles distant from the Cinchona Botanical 
Garden. 
The prothallia differed from those of D. simplicifolia, Rudge, described 
by Brebner, in their much larger size and elongated form. Most of the 
larger ones, which reached a length of 25 mm., were several times 
longer than wide, and often the posterior end was much attenuated and 
quite thin, the archegonial cushion not extending into it. Forked prothallia 
were also found, and one specimen of D. Jenmani had four archegonial 
cushions. 
The margin of the prothallium is often deeply lobed like that of 
Osmunda or Gleichenia. The rhizoids as described by Brebner for 
D. simplicifolia are multicellular. 
The archegonia and antheridia resemble in form those of the other 
Marattiacess, but the former are remarkable for the imperfect development 
