36 
CONTRIBUTIONS TO BOTANY. 
standing these prominent marks of ordinal distinction, there 
exists a regular gradation from one family to the other, as will 
be seen from the analyses I propose to offer ; this proceeds from 
one extreme, Opilia (where the disk is developed in distinct free 
glands), through Agonandra, Olax, Liriosma, Cathedra, Schupfia, 
Arjoona, Quinchamalium, Myoschilos, lodina, Cervantesia, Mida, 
Exocarpus, Santalum, &c., rendering it difficult, through the 
osculant genera lodina and Cervantesia, to draw a line through 
the strong limits of demarcation that exist between the two 
families. 
The word torus has been employed by Mr. Bentham (Linn. 
Trans, xviii. p. 676) to describe in Olacacece what I have termed 
a disk, and which I have shown to be the same organ, but dif- 
ferently situated, that forms a eonstant feature, both in that 
order and the Santalacece, where in both cases, with rare excep- 
tions, it is always deeply cupuliform and more or less lobed on 
its margin. I have adopted in preference the term “ discus cu- 
puliformis ” as that given by Dr. Lindley for such a structure 
in his ‘ Introduction to Botany,’ p. 161. This may not differ in 
its nature from a stipitate torus, but the adaptation in such cases 
of this last term, which is generally used in another sense, will 
naturally lead to ambiguity in om- definition of structural ar- 
rangement ; thus Mr. Bentham, in a subsequent work, appears 
to agree with Dr. Hooker’s observation, after an original sug- 
gestion of Mr. Bi’own, in what appears to me an inconsequent 
conclusion, viz. that because in Olacacece the corolla is inserted 
into the disk, which is sometimes stipitate, or what he calls the 
apex of the pedicel, the calyx in such case should be consi- 
dered in the light of an involucre (Flor. Nigrit. p. 261). I can 
perceive no reason why this should ,be a necessary consequence, 
for we see in the Capparidacece the development of the stipitate 
torus carried even to a much greater extent, supporting the sta- 
mens on its sides and the petals below them ; but no botanist in 
these instances has ever thought of considering the calyx to be 
of the nature of an involucre, which it ought to be if the above 
reasoning were valid this incongruity is rendered still more evi- 
dent, when we remember that the argument was applied in the 
case of Rhaphiolepis, a genus of the Icacinece, which I have shown 
to diff'er little from the Aquifoliacece. The word torus is gene- 
rally confined to that fleshy termination of the peduncle in the 
bottom of the calyx seen in Ranunculacece, and more especially 
developed in such orders as the Anonacece, Magnoliacece, &c., but 
when it rises in more varied or determinate shapes, it takes the 
name of hypogynous glands, annular ring, flat, pulvinate or 
cupuliform disk, &c., according to the peculiar form it may 
assume, or the position in which it is engendered. 
