APPENDIX. No. V. 429 
natives of America only, are also contained in the collection; and the loftiest 
tree seen on the banks of the Congo, is a species of Bomba, which, as 
far as can be determined from the very imperfect specimens preserved in 
the herbarium, does not differ from Bombax pentandrum of America and 
India. I have formerly remarked* that Malvaceze, 'Tiliaceze, Hermanniacea, 
Butneriaceze, and Sterculiaceze, constitute one natural class; of which the orders 
appear. to me as nearly related as the different sections of Rosaces are to 
each other. In both these, as well as in several other cases that might be 
mentioned, there seems to be a necessity for the establishment of natural classes, 
to which proper names, derived from the orders best known, and differmg 
perhaps in termination, might be given. 
It is remarkable that the most general character connecting the different orders 
of the class now proposed, and which may be named from its principal order 
Malvacez, should be that of the valvular estivation of the Calyx: for several, 
at least, of the genera at present referred to Tiliaceze, in which this character 
is not found, ought probably, for otler reasons likewise, to be excluded from 
that order: and hence perhaps also the Chlenaceze, though nearly related, are 
not strictly referable to the class Malvaceze, from all of whose orders, it must 
be admitted, they differ considerably in habit. 
LEGUMINOS. According to Baron Humbolt,+ this family, or class, as 
I am rather disposed to consider it, constitutes one-twelfth of the Phanogamous 
plants within the tropics. Its proportion, however, is much greater in Pro- 
fessor Smith’s herbarium, in which there are 96 species belonging to it, or 
nearly one-sixth of the whole collection. And, ample allowance being made 
for the lateness of the season when the collection was formed, which might be 
supposed to reduce the number of this family less than many of the others, 
Leguminosee may be stated as forming one-eighth of the Phenogamous plants 
on the banks of the Congo. In India, it probably forms about one-ninth, 
which is also nearly the proportion it bears to Phanogamous plants in the 
equinoctial part of New Holland. 
I have formerly proposed to subdivide Leguminosz into three orders.} 
Of the first of these orders, MIMOSEAE, there are only eight species from 
* Flinders’s Voy. 2, p. 540. + op. cttat. £ Flinders’s Voy. 2, p. 551. 
