288 DR. M. T. MASTERS ОМ SOME POINTS ІМ 
follows :—The rounded end of the receptacle gives off first of all five sepals in successive 
order. These attain relatively considerable dimensions before the five staminal tubercles 
which come next in order are simultaneously protruded (Pl. XX XIX. fig. 1) and alter- 
nately with the sepals (Pl. XXXIX. fig. 2). After the staminal tubercles have advanced 
somewhat—after, indeed, the antheral portion is separated from the filament, the 
tubercles which are to form the petals are protruded apparently from the back of the 
filament (Pl. XXXIX. figs. 8,4). Isay apparently, because what really takes place (in 
Primula) is this. After the formation of the staminal tubercles the thalamus pushes 
out the petalline tubercles, one at the -very base of the outer surface of each of the 
filaments, and so close to it that it seems to arise from the filament itself; the receptacle, 
continuing to grow in the form of a tube (Pl. XXXIX. fig. 4), upraises the corolla- 
tube, and with it the stamens. While thisis taking place the extreme apex of the recep- 
tacle is pentagonal and tabular in appearance, or slightly depressed in the centre 
(PL XXXIX. fig. 2). On its raised edge five small tubercles sometimes appear simul- 
taneously, which are the carpels (Pl. XXXIX. fig. 5). These five tubercles are gra- 
dually raised from below by the lengthening of the receptacle in a tubular manner 
(Pl. XXXIX. fig. 6), so that we have soon a flask-shaped pistil with a narrow neck and 
open mouth (figs. 7 & 8). Within the rudimentary pistil so sketched out the receptacle 
changes its former flat or depressed condition for a convex or dome-shaped appearance; 
the middle portion of this dome speedily becomes covered with ovules from above down- 
wards; the upper portion elongates into a naked cone; and the lower portion forms a 
stipes, which is apparently quite free from the walls of the pistil. Fig. 9 shows a plan 
of a vertical section through the flower at this stage. "The neck of the pistil gradually 
lengthens into a style, becomes closed; and so we have ultimately the perfect ovary, with 
whose appearance every one is familiar *. 
Chorisis.—Adverting now to the teratological appearances presented by the individual 
petals, it may be mentioned that the petals of Primulacez are frequently the subjects of 
lateral chorisis or fission. Slight instances of this are seen in the petals of the common 
Primrose, in the central notch by which they are characterized. If this subdivision be 
carried further we may have deeply bipartite petals, or fringed ones, as in Soldanella ; 
and if the process be earried to an extreme, we have ten petals in the place of five, as 
is not uncommon in Primroses and Cyclamen? (Pl. XXXIX. fig. 10). This lateral 
branching of individual petals must not be confounded with the dialysis or complete 
separation of one petal from another, which has been observed in the flowers of Anagallis $ 
and other genera, and which is the normal condition in the genera Asterolinum and 
 -Apochoris. 
Enation, or outgrowth from the surface of the petals, is a process scarcely distinguish- 
able from transverse chorisis except by the later period at which it occurs. Chorisis, 
as I understand it, is a congenital process, beginning with the growth and continuing 
* Quite as frequently, as far as I have observed in Lysimachia and Primula, the pistil originates as a ring, which 
grows upward from beneath so as to form a tube, upon whose edge the five tubercles are not formed till quite late 
in development, and in some cases, especially in monstrous flowers, not at all (Pl. XL. fig. 4). 
T * Vegetable Teratology,’ p. 359. | $ Г. с. p. 73. 
