170 
ORGANOGRAPHY. 
BOOK I. 
processes of the crown of Passiflora are also apparently of this 
nature. 
The petals are often furnished with little appendages 
{Jig. 105.), which are either inner rows of petals in a state 
of adhesion to the first row, or modified stamens; which it is 
sometimes difficult to ascertain. Many of these enter into 
Linnaeus’s notion of nectarium, although nearly the whole of 
them are destitute of any power of secreting nectar or honey. 
100 101 102 
103 104 105 
The most common form of appendage is the corona^ which 
proceeds from the base of the limb, forming sometimes an un- 
divided cup, as in Narcissus {Jig. 104.), when it becomes the 
scyphus of Haller ; sometimes dividing into several foliaceous 
erect scales, as in Silene and Brodiaea, when it forms the lamella 
of some writers; occasionally appearing as cylindrical or clavate 
processes, as in Schwenckia and Tricoryne, where it is mani- 
festly modified stamens ; and even in some instances forming 
a thick solid mass covering over the ovarium, and adhering to 
the stamens, as in Stapelia ; when it is called the orbiculus. 
Parts of this last form of corona bear several names, which 
are found useful in avoiding repetition in describing the com- 
plicated structure of this kind of appendage. The whole mass 
of the corona is the orbiculus^ or saccus, or stylotegium ; cer- 
tain horn-like processes are cornua^ or horns ; the upper end 
of these is the beak, or rostrum, and their back, if it is dilated 
and compressed, is the ala, or appendix ; occasionally there is 
