POSTSCRIPT. 
39 
term by Jussieu is one leaf doubled enclosing another; every 
Amaryllidaceous leaf encloses another with its base, and 
some vaginate very high, but such base is usually cylindrical. 
When it is flattened, as if by compression, the true equitant 
form is exhibited; but the difference is the compressed habit, 
not the structure. I observe that Dr. Lindley calls leaves 
flat in contrast with equitant, which is an unsatisfactory 
term, since most of those so called flat are deeply chan- 
nelled, and the others often really flat ; but there is no true 
contrast, and therefore an applicable expression could not be 
found. If all leaves that enclose another with their base are 
properly equitant, the distinction of such would be, base 
compressed and base cylindrical, lamina edgeways and 
lamina confronted. It will even be found that some Iri- 
daceous plants, as Homeria, have a compressed base with 
confronted leaves, bearing an intermediate form. 
Dr. Lindley has associated Xerophyta, Vellosia, and 
Barbacenia, with Bromeliaceae. It is impossible that a 
person embracing such a very wide field as an arrange- 
ment of the whole vegetable system, should have at the 
first under his view all the considerations which present 
themselves readily to one who is investigating a parti- 
cular branch of that system, and I feel quite confident that 
my worthy friend on mature consideration will perceive that 
this cannot do. Bromeliaceae had two definite and impor- 
tant features, ovary superior, and perianth tripetaloid, 
that is, having three conspicuous petals, and three short 
sepals like a calyx. Dr. Lindley, detaching Vellosia and 
Barbacenia from Hypoxideae, and uniting Xerophyta with 
them, brings the order Bromeliaceae out of its proper place 
to unite with them, and in so doing overturns its character. 
Its ovary is superior, and it is brought into the class with 
inferior ovary on account of its mealy leaves, but not one of 
those three genera to which it is brought has mealy leaves ; 
and it cannot be understood how that feature is to stand in 
lieu of the other. It thus becomes necessary to engraft on the 
character of Bromeliaceae an alternative which is fatal to it 
as a distinguishing character (“ calyx usually calycine, some- 
times petaline"), and entirely to drop the position of the 
ovary, which in other parts of the system is made conspi- 
cuous. I cannot too distinctly declare that nothing polemic 
is intended by my remarks ; that I have no wish but to con- 
sider dispassionately how a satisfactory arrangement can be 
