THE NUMBER OF STAMENS AND CARPELS. 219 
conditions; to Bennett” (Stellaria), Ludwig * and Vichting”, by 
want of light; to Graebner”, by unsuitable relationships of 
light to temperature; and, according to Ludwig", in Collomia 
grandiflora it is the apical flowers which are cleistogamic. 
Further, there are many well-known cases in which cleistogamic 
flowers regularly precede or follow chasmogamic flowers on the 
same plant. Do such influences affect the number of sexual 
organs in a flower? It is very probable; for is not cleistogamy 
often associated with reduction in the sexual organs, and re- 
duction in the corolla associated both with cleistogamy and with 
abortion of one sex in gyno- or andro-diccism ? Further experi- 
ments, it is hoped, will throw more light on this question. 
STELLARIA MEDIA, Cyr. 
The number of stamens in this plant is known to be very 
variable. A glance at Table I. will show that every possible 
number of perfect stamens, from 0 to 10, was found among the 
5684 flowers recorded iu it. Chasmogamic and cleistogamic 
flowers are not distinguished from each other in it. 
Plants growing under different conditions were examined. 
The following explanations will suffice :— 
(A) From a hayfield by the river Cam near Barnwell, close to 
Cambridge. These plants were examined weekly, through 
February and half of March, and afterwards as occasion per- 
mitted. They competed with the growing grass ; and while this 
remained short, received sufficient sunlight. The locality is 
damp. 
(B) From a garden almost adjoining the hayfield (A). There 
was no competition, but the locality is rather shaded. The 
plants were examined as in the last. 
25 «On the Fertilization of Winter-flowering Plants." Nature, i. p. il 
(1870). _, 
26 Review of Hoffmann's * Culturversuche ii. Variation.’ Bot. Centralblatt, 
xx. p. 266, footnote. f . . 
27 « Ueber d. Einfluss d. Lichtes auf d. Gestaltung u. Einlage d. Blüthen. 
Pringsheim's Jahrbuch, 1893, xxv. p. 149. f f 
23 « Ueber gelegentliche Kleistogamie.” Verhandl.d. Bot. Vereins d. Provinz 
Brandenburg, 1893, xxxv. p. 148. o f 
29 « Zur Kleistogamie u. Samenverbreitung d. Collomien.” Bot. Zeitung, 
xxxvi. p. 739 (1878). 
