82 
Mr. Brown’s Observations on the 
number of the Nouveau Bulletin des Sciences, the disposition of 
vessels in the corolla is expressed in the following terms: 
“ Chacun des cinq petales dont se compose la corolle est muni 
de deux nervures tres simples qui le bordent d’un bout a l’autre 
des deux cotes, et confluent par consequent au sommet.” 
On this statement I have several remarks to offer. And first, 
I object to its hypothetical language. Whatever opinion may 
be formed of the theory here adopted by the author, namely, that 
every monopetalous corolla is in reality composed of several con¬ 
fluent petals; a theory first proposed by Linneus himself in his 
Prolepsis Plantarum, and ably supported on different grounds by 
Mons. Decandolle in his excellent Theorie Elementaire de la 
Botanique; I can see no advantage in adopting its language in 
stating a fact of this kind, especially if proposed as a practical 
character. 
For my own part, I consider this opinion as correct in the sense 
in which it was held by Linneus, without, however, connecting with 
it the ingenious hypothesis of M. Decandolle, namely, that petals 
are only modified stamina. It remains to be seen on what ground 
M. Cassini has adopted this theory, as proposed by M. Decan¬ 
dolle, for Composite, the only family which seems to present a 
very important objection to it, in having its principal, and in the 
greater part of the order its only, vessels occupying the lines of 
junction of the supposed united petals. 
To adapt this disposition of vessels to the theory, M. Cassini is 
obliged to subdivide their apparently simple trunks; a division, 
however, which may be regarded as entirely hypothetical. From 
the observations I have made on the subject, I have no doubt that 
these trunks are equally simple with the secondary nerves when 
present, or with the primary in other families. I find them to con¬ 
sist of two kinds of vessels, the spiral and ligneous. Of the spiral 
vessels 
