ever tells me
whether one pair of petals is always smaller than the other, or not. Only I
see it says the corolla has four petals. Perhaps a celandine may be a
double poppy, and have eight, I know they're tiresome irregular things, and
I mustn't be stopped by them;[23]--at {73} any rate, my Roman poppy knew
what it was about, and had its two couples of leaves in clear
subordination, of which at the time I went on to inquire farther, as
follows.

13. The next point is, what shape are the petals of? And that is easier
asked than answered; for when you pull them off, you find they won't lie
flat, by any means, but are each of them cups, or rather shells,
themselves; and that it requires as much conchology as would describe a
cockle, before you can properly give account of a single poppy leaf. Or of
a single _any_ leaf--for all leaves are either shells, or boats, (or solid,
if not hollow, masses,) and cannot be represented in flat outline. But,
laying these as flat as they will lie on a sheet of paper, you will find
the piece they hide of the paper they lie on can be drawn; giving
approximately the shape of the outer leaf as at A, that of the inner as at
B, Fig. 4; which you will find very difficult lines to draw, for they are
each composed of two curves, joined, as in Fig. 5; all above the line _a b_
being the outer edge of the leaf, but joined so subtly to the side that the
least break in drawing the line spoils the form.

14. Now every flower petal consists essentially of these two parts,
variously proportioned and outlined. It {74} expands from C to _a b_; and
closes in the external line, and for this reason.

[Illustration: FIG. 5.]

Considering every flower under the type of a cup, the first part of the
petal is that in which it expands from the bottom to the rim; the second
part, that in which it terminates itself on reaching the rim. Thus let the
three circles, A B C, Fig 6., represent the undivided cups of the three
great geometrical orders of flowers--trefoil, quatrefoil and cinquefoil.

[Illustration: FIG. 6.]

Draw in the first an equilateral triangle, in the second a square, in the
third a pentagon; draw the dark lines from centres to angles; (D E F): then
(_a_) the third part of D; (_b_) the fourth part of E, (_c_) the fifth part
of F, are the normal outline forms of the petals of the three {75}
families; the relations between the developing angle and limiting curve
being varied according to the depth of