THE REV. С. HENSLOW ОХ THE ORIGIN ОҒ FLORAL ASTIVATIONS. 179 
so that one, the first, is entirely outside the adjacent parts, while the last is entirely 
within. This is deduced from the last by allowing the third member to slip one edge 
under the fifth, in addition to the second being under the fourth (Tab. XXV. fig. 6). 
б. Convolute and contorted.—In these each part of the whorl overlaps one adjacent 
part by one of its edges, and is in turn overlapped by the other adjacent part (Tab. XXV. 
fig. 7). Thisis deduced from the preceding in a similar manner to that—namely, by 
passing an edge of the first part under that of the third. 
Hence it will be seen that Nos. 3, 4, 5, and 6 are closely connected, and may be briefly 
expressed by saying the half-imbricate is formed from the quincuncial by having the 
4th member over the 2nd, the imbricate proper from the half-imbricate, by having 
the 4th over the 2nd and the 5th over the 3rd, the convolute from the imbricate proper 
by having the 4th over the 2nd, the 5th over the 3rd, and the 3rd over the 1st *. 
7. Valvate.—In this the edges of adjacent parts touch only, but do not overlap. The 
two main varieties, besides the simply valvate, where the edges just touch, are :— 
Induplicative, where the edges are rolled inwards; reduplicative, where the edges are 
rolled outwards. 
8. Straight or open.—In this the parts of the whorl are not sufficiently developed to 
meet even as in valvate, and therefore the wstivation may be said to be indeterminate. 
ПТ. Tur DEGREES OF FREQUENCY OF THE VARIOUS KINDS ОҒ /ÉSTIVATION. 
The following percentages are deduced from Le Maout and Decaisne, as stated above. 
І. Dicotyledonous Angiosperms. 
А. IMBRICATIVE. 
1. Equitant Оају зз уу ул або 4 p. c. 
x СОМА > -= ac 2.2. 5 2 
2. Tristichous, Calyx, or Corolla . . . д ITI 
3. Pentastichous, Calyx, with Cor. various 2 A 
Е Corolla, with Calyx ,, ds IU ees 
x both Calyx and Corolla 2” li 
4. Half-imbricate (excluding Papiliona- 
ceous and cochleate varieties) . . » 15 4 
5. Imbricate proper, Calyx, apparently 
very rare, as in Cyclamen, p. 529. 
Imbricate proper, Corolla .... » 9, 
6. Convolute, Calyx, apparently rare. 
Dam . . i x s = 16 .„ 
33 
* Prof. A. Gray’s paper is chiefly directed to the settlement of the proper term for this kind; and һе сопсіпдев that 
“ eonvolute" is preferable to ** contorted," as the latter does not differentiate corollas with a torsion, the petals of 
which have each a spiral axis, from those with no torsion, or whose axisis erect. А third term, * obvolute," would, 
he observes, claim priority as having been used by Linnsus ; but it has not been in common usage. Ав the Professor 
concludes with the words, “ I should hope rather than immediately expect that this use would become general,” 
I have the satisfaction of fulfilling those expectations immediately ; for although this paper was written before 
Prof. Gray’s was published here, and I had adopted the word “ contorted,” I have altered it in every case to 
“ eonvolute," in accordance with his wish. 
202 
