CHAP. I. REGULAR METAMORPHOSIS. 
535 
is also true of the corolla. There are also cases in which the 
petals have actually reverted to the state of leaves. In a 
Campanula Rapunculus, seen by Roper, the corolla had 
become five green leaves like those of the calyx ; the same 
was found in an individual of Verbascum pyramidatum, de- 
scribed by Du Petit Thenars ; proliferous flowers of Geum 
and Rosa, in which the petals were converted into leaves, are 
adduced by Linnaeus. 
The third whorl, or series of the fructification, is occupied 
by the stamens. These often consist of a single row, equal in 
number to the divisions of the corolla, with which they are, 
in that case, alternate. The exceptions to this in flowers with 
a definite number of stamens are not numerous ; and such as 
do occur are to be considered as wanting the outer row of 
stamens, and developing the second row instead. Thus in 
Primulaceae, in which the stamens are opposite to the petals, 
and therefore belonging to a second whorl, the first makes its 
appearance in Schwenkia, which undoubtedly forms part of 
the order, in the form of clavate or subulate processes arising 
from the sinuses of the limb. These and similar processes, 
which are far from uncommon in plants, and which are known 
by a number of different names, such as scales of the orifice 
of the corolla, glands, nectary, cup, &c. are in most cases me- 
tamorphosed stamens. In Narcissus the cup is formed of 
three stamens of the first row, become petaloid and united at 
their margins; while the six, which form the second and 
third rows, are in their usual state, and within the tube. 
This is shown, firstly, by the frequent divisions of this cup 
into three lobes, which then alternate with the inner row of 
perianthium, or the petals ; secondly, by a distinct tendency 
in double Narcissi, particularly N. poeticus, to produce abor- 
tive anthers on the margin of the lobes of the cup ; and, 
thirdly, by the genus Brodiaea and its allies. In that genus 
the crown of the original species consists of three petaloid 
pieces, not united into a cup as in Narcissus, but wholly 
separate from each other : in Leucocoryne ixioides these 
pieces are not petaloid, but clavate ; and in Leucocoryne 
odorata the pieces have the same figure as in L. ixioides, but 
almost constantly bear more or less perfect anthers. That 
M M 4 
