FLOWER OF GNETUM 
163 
solitary stamen , (2) a monadelphous group of two stamens 2 5 (3) a prolonga- 
tion of the floral axis bearing one or two sessile anthers 3 . The envelope is 
(1) a perianth, calyx or perigone 4 ; (2) a vaginula 5 ; (3) a pair of fused 
bracteoles 6 or bracts; (4) a membranous basilar sheath 7 . If the antherophore 
is a foliar structure, i.e. a stammal filament or two or more concrescent 
filaments, the interpretation of the morphology of the envelope becomes of 
first-rate importance, for upon it rests the responsibility of raising the whole 
structure to the rank of a flower. 
Hooker 8 , impressed by the structure of the pseudobisexual flower of' 
Welwitschia, suggested that the male flower of Ephedra— and, by inference, 
that of Gneturn — was derived from an ancestral type now represented by 
W elwitschia, by the total abortion of the ovule and its accessory structures. 
This idea seems to have prevailed more or less indefinitely until, within 
recent years, it has become more generally accepted 1 ’. In their discussion, 
Arber and Parkin made a strong point of the generally received opinion that 
the six stamens of Welwitschia, like the two of Gneturn, arise from the 
opposite primordia 10 . But this view of the origin of the Welwitschia 
androecium is discarded by Church 11 , who shews reason for regarding it as 
“ a single whorl of six equal members.” This fact does not of course 
invalidate the comparison, but it robs it of much of its force. It may 
fairly be said that at the moment there is no conclusive evidence to support 
the conception that the male flower of Gneturn is derived by reduction 
from a bisexual strobilus 12 . 
The fact that so many writers have regarded the male flower as a 
strobilus, although some have adopted interpretations of its parts which are 
not readily compatible with this view, at least indicates that no other 
explanation obviously offers itself. That it is in some degree a natural view 
to take of the adult flower no one will deny. But those who have advocated 
it have not sufficiently considered the earlier stages of development nor have 
they satisfactorily explained certain apparently discordant facts established by 
a study of the details of the adult structure. 
1 Blume, 1834, p. 101; Tulasne, 1858, p. 113; Pavlatore, 1868, p. 348; Le Maout and 
Decaisne, 1868. 
2 Lindley, 1853; Hooker, 1863, p. 23 ; Eichler, 1863, p.*17 ; Van Tieghem, 1884; Worsdell, 1901. 
3 Strasburger, 1872, p. 157; Coulter and Chamberlain, 1901, 1910. 
4 Blume, 1834, p. 102; Endlicher, 1847 ; Lindley, 1853; Tulasne, 1858, p. 112; Hooker, 1863, 
p. 23; Eichler, 1863, p. 16. 
5 Meyer, 1846. 
8 Parlatore, 1868, p. 348; Thibout, 1896; Coulter and Chamberlain, 1910, p. 371. 
7 Le Maout and Decaisne, 1868. 
8 Hooker, 1863, p. 24. 
9 Coulter and Chamberlain, 1901, p. 120 ; Arber and Parkin, 1908, p. 497, Lotsy, 1 11 , P- 
10 Arber and Parkin, l.c. p. 502, fig. 3 iv, and v. 11 Church, 1914, p. 133. 
12 Strasburger arrives at the same conclusion for Ephedra, 1872, p- 139. 
