ANATOMY OF THE GENUS SALICORNIA. 327 
about three or four segments below the one in which suberisation can first be 
detected. The cell-walls of the aqueous tissue of the foliar sheath show at 
this stage a tendency to collapse, a little lower down the shoot they do so com- 
pletely, and finally the sheath is torn or rubbed off, separation taking place in 
the innermost sheath layers (Pl. 15. fig. 3). 
9. The Morphology of the Seedling. 
The seedling possesses two small fleshy cotyledons and a short thick 
hypocotyl (Pl. 15. fig. 4, « & b). The seed leaves show no development of a 
palisade layer, but the aqueous tissue is well marked. The two cotyledons 
(с.1, ¢.2, text-fig. 7, 1 2) fuse laterally towards their base and form a short 
cotyledonary tube or sheath (c.5s.), in a manner precisely comparable to the 
leaf-sheath of the vegetative shoot in the mature plant; this tube finally 
unites with the hypocotyl and is decurrent down it as a succulent * cortex.” 
The behaviour of the vascular strands of the cotyledons again exactly agrees 
with that of the foliar traces. 
Two bundles pass out from the hypocotyl, one to each cotyledon ; as soon 
as they leave the hypocotylar region each divides into three (cb./, cb.2, text- 
fig. 7, 3), the median strand of each branches and supplies the seed leaf with 
vascular tissue, the two lateral strands curve outwards and downwards into 
the hypocotylar “ cortex,” branch once or twice, the branches anastomose 
somewhat, and finally they die out towards the lower end of the hypocotyl 
(h.c.b., text-fig. 7, 3 & 4). The hypocotyl of the seedling is thus provided 
with a double series of bundles, an inner hypocotylar ring (reinforced in older 
serles by the epicotylar strands), and an outer series also of cotyledonary 
origin. There is thus absolute agreement between the behaviour of the 
'aseular strands in the three foliar categories of leaves, bracts and 
cotyledons. 
6. The Morphology of Species of Allied Genera. 
Among the various genera placed by Volkens * 
in the group Salicornie:, 
many are described as jointed and apparently leafless ; the following genera 
are included in this class—Spirostachys, Halostachys, the long shoots of Halo- 
cnemum, Tecticornia, Arthrocnemum, Salicornia and Microenemum. Fresh 
material not being available, herbarium specimens of representatives of the 
remaining genera, with the exception of Heterostachys, were examined. In 
Kalidium foliatum alternately arranged leaves exist ; these leaves are small 
and are characterised by the decurrence of the leaf-base, which extends 
from the node, down the stem to the internode below. A. arabicum shows 
a similar decurrence of the leaf-base, but the fused part appears almost 
tubular, extending more than halfway round the stem. The leaves of 
* Engler & Prantl, Natürlichen Pflanzenfamilien, Teil iii, Abt. 1 A (1894). 
