NOTES 
DEVELOPMENT OF THE STOMA IN GNETUM GNEMON. — In connexion 
with my study of Welwitschia 1 I may here describe the development of the stoma in 
Gnetum Gnemon, which shows a similar type to the former plant. The structure of 
the stoma is very much the same as already described in Gnetum africanum . 2 
Stomata are present on the under surface of the leaf, except on the veins, and are 
irregularly orientated. A mature epidermal cell has a sinuous outline resembling 
that in Tmesipteris. One of the epidermal cells becomes an initial cell which 
divides into two by a line usually parallel to the long axis of the cell (Fig. i). One 
of these cells divides again in the same way (Fig. 2). In the normal case, the 
Figs. 6, 7. Transverse and longitudinal divisions of subsidiary cells, x 830. 
central one of these three cells will become a stoma-mother-cell, which subse- 
quently divides in the same fashion, giving rise to two guard-cells (Figs. 3, 4) ; the 
other two will be subsidiary cells. Thus a stoma with two subsidiary cells is formed 
from one single epidermal cell. 
Sometimes one or both of the subsidiary cells divide longitudinally, transversely, 
or obliquely (Figs. 8, 9), so that more than four cells are cut from an initial cell. In 
such a case those cells which immediately border upon the guard-cells seem to function 
as subsidiary cells. This further division of subsidiary cells may start before the guard- 
1 Takeda: Ann. Bot., xxvii, current number, 1913. 2 Duthie : Ann. Bot., xxvi, 1912, p. 600. 
[Annals of Botany, Vol. XXVII. No. CVI. April, 1913.] 
