574. Notes on the Flowering of Saxifraga sarmentosa. [August, 
lower side of a whorl develop first? The lower petals are 
enlarged to serve the purpose mentioned above. This requires 
more nourishment to pass through the lower side of the peduncle, 
and in this nourishment the stamens on that side share 
The earlier development of stamens on opposite sides of hori- 
zontal pairs, according as those pairs. are above or below, is avery - 
curious fact indeed. To explain it and the whole order in the 
maturing of the stamens, we will venture the following. 
The flowers are quite perfectly pentamerous; the leaves also 
present the five-ranked arrangement. Remembering the order in 
which leaves unfold from the bud, and following, for the stamens 
of the first flower at the top of the panicle, a spiral in the same 
direction, as that found in the rosette of leaves at its base, we have 
the numbers in Fig. 4 a expressing their order of maturing. 
Assuming that the increased size of the lower petals is associated 
with an increase of nourishment in the lower side of the peduncle, 
and that the stamens are likely to share in this excess of nourish- 
ment according to their distance from the lower side of the flower, 
the numbers in Fig. 44 express the probable order of maturing 
a b c 
2 5 6 6 8 de 
o o ° o o © 
10 5 : 15 
o e 
7 8 4 4 11 13 
o ° o o ° sf 
° o o o o Gi 
4 3 3 3 7 ó 
o o o o o 
9 6 2 2 11 8 
o o o 
I I 2 
Fic. 4.—A Prae e illustrating the order of development of the stamens on ' 
mentosa ; a, order evelopment derived from phyllotaxy; 4, order resulti rom 
distance from ‘et side of flower; c, æ and 4 combined. 
if left to this influence alone. If we assume that both influences 
are acting simultaneously, the sums of these numbers as given in 
Fig. 4¢, will express the order in which the stamens ought to 
mature when the longer lower petal is on the left side, for such - 
was the case in the particular flower under consideration. Using ae 
the numbers for the stamens given in Fig. 2, and referring to Fig. 
4 ¢, we find that theoretically they should mature in the following 
order: 1, 2, 5, (4,7,) (3,6,10,) 8, 9. This corresponds exactly — 
with the order frequently observed. The only discrepancy is- 
