CHAP. IT. 
BISK. 
161 
they are called sterile stamens^ and are frequently- only to be 
recognised by the position they bear with respect to the other 
parts of the flower. Botanists consider every appendage, or 
process, or organ, that forms part of the same series of organs 
as the true stamens, or that originates between them and the 
pistil, as stamens, or as belonging to what Roper calls the 
andrceceum, namely, to the male system ; and every thing on 
the outside of the fertile stamens is in like manner usually 
referred to modifications of petals, a remarkable instance of 
which is exhibited by Passiflora. The appearances assumed 
by these sterile stamens are often exceedingly curious, and 
generally extremely unlike those of the fertile stamens ; thus 
in Canna they are exactly like the petals ; in Hamamelis they 
are oblong fleshy bodies, alternating with the fertile stamens ; 
in Pentapetes they are filiform, and placed between every 
three fertile ones ; in Scitamineae they are minute gland-like 
corpuscles, a very common form (Plate IV. fig. 10. c) ; in 
Brodiaea they are bifid petaloid scales ; and in Asclepiadeae 
they undergo yet more remarkable transformations. Dunal 
calls these sterile stamens lepals (lepala) ; a term which has not 
yet been adopted. 
9. Of the Disk. 
By this term are meant certain bodies or projections, situ- 
ated between the base of the stamens and the base of the 
ovary, but forming part with neither ; they are referred by 
the school of Linnaeus, along with other things, to nectarium : 
Link calls them sarcoma and perigynium ; and Turpin, phy- 
costemones. The most common form is that of a fleshy ring, 
either entire or variously lobed, surrounding the base of the 
ovary (Plate V. fig. 4. e, 8. d), as in Lamium, Cobaea, Gra- 
tiola, Orobanche, &c. ; in Gesnerieae and Proteaceae the disk 
consists of fleshy bodies of a conical figure, which are 
usually called glandulce liypogynce. It occasionally assumes 
the appearance of a cup, named by De Candolle in Paeonias 
and Aconites lepisma, a bad term, for which it is better to say 
discus cyathiformis. In flowers with an inferior ovary (Plate 5. 
fig. 9. c, 7. c) the disk necessarily ceases to be hypogynous, and 
generally also to appear in the form of scales. In Compositae 
M 
