
STIPULES. 235 
dcoant of the definite bud-scales, the above instances having 
only one. Rubiacez, Rhizophorez, etc. two or three, accord- 
ing to the number of leaves; many plants indefinite as 
Sedgwickia, CEsculus, and most northern plants. They may 
be, as is often the case, rudimentary, and as in some tropical 
forms, entirely wanting. 
ith regard to Rubiacee, I may observe further, that the 
midrib of each stipule is single and central, not double and 
lateral, as would be the case were they due to cohesion of two 
' distinct leaflets ;* for although Link says, that the line cor- 
. responding to the margin of union is generally vascular, it is 
almost invariably evascular.t The only exceptions being, I 
believe, in the corolla of Composite, as was long ago observed 
by Mr. Brown. 
Stipules are not distinguishable from the interpetiolar pro- 
cesses of Apocynee, but by their development and cellularity ? 
The whole tenor of Adrien Jussieu on this head is to 
. attribute division of the leaves and stipulæ, to the disposition of 
the fascicles of vessels in the stem, and their points of exit. 
The function is not so variable as the origin; in all cases 
the organ appears protectant;in many as in Bucklandia, and 
Hymenea, it is palpably so. — 
Very generally, therefore they are temporary organs, but 
they often combine as might be expected, both protecting and 
aérating functions. 
* If the stipulz are, as defined at the base of the petiole on 
each side, or as attached to each side of the base of the pe- 
tiole, it is, I think, inferable that the scar or cicatrix or base 
should be on the plane with the base of the petiole, as it is in 
Magnoliacee. 
But this is not the case in Rhizophoree, Ficus, etc. in which, 
the former at least, the base or cicatrix, is evidently within, 
and altogether on another plane. 
* See Link, p. 260, addiderim quod vera coalitio plerumque segmento nervoso 
nec enervio fiat. 
5, where he says plerumque nervus per medium segmentum 
ee Link, p. 
ad apicem usque decurrit, etc. 

