and Anatomy of Brownea and Saraca. 313 
rank as dorsiventral structures, while in Brownea they are, 
by adaptation or reversion, radial structures. Suppose now 
that the flower-leaves themselves were caulomes, not phyl- 
lomes ; then, taking for our guide the aphorism that develop- 
ment, i. e. ontogeny, can alone elucidate the true nature of a 
structure, we should be constrained to refer the development 
of the flower in the two species to different types of branch- 
ing. Now I do not see how the substitution of phyllome 
for caulome can modify the validity of the precept. If we 
regard the scorpioid inflorescence of a Cordia as morpho- 
logically different from that of a Borago , that of one species 
of Urtica as different from that of another, we must admit 
that the flower of Brownea is morphologically different from 
that of Saraca , Cassia , Mimosa , and every leguminous flower 
that has been studied ; and herein we have a reductio ad ab- 
surdum of the above aphorism. 
II. The Distribution of the Floral Leaf-Traces in 
Brownea and Saraca. 
This was the next problem to attack in order to see if it 
would shed any light on the morphology of the floral tube ; 
but I soon discovered that the anomalies presented needed 
themselves to be explained before they could be utilised to 
explain other difficulties. 
1. The bractlets . The arrangement in Saraca presents no 
difficulties. The fibro-vascular cylinder of the pedicel below the 
bractlets consists of six little arcs, two anterior, two posterior, 
and one on either side. The lateral arcs detach themselves 
at the node to go one to either bractlet, the one to the lower 
bractlet at a slightly lower level ; in other words, each bractlet 
sends down a single leaf-trace which enters the cylinder at 
the extremity of the lateral axis. 
In Brownea the bractlets send down numerous traces which 
are inserted uniformly at equal distances all round the pedicel. 
We must regard this distribution as a mere matter of con- 
venience as it were ; for, considering the development of the 
bracteolar sheath, the general occurrence of paired bractlets 
Y 
