ANATOMY OF THE GENUS SALICORNIA. 319 
with a broad base of insertion, the leaf-bases of a pair of leaves nearly 
surrounding the stem at the node. Subsequently lateral fusion takes place 
between the adjacent margins of each pair of leaves, producing a connate 
leaf-base (text-fig. 3, 2), and meristematie activity in this region finally 
results in the production of a tubular leaf-sheath, which is crowned with 
the two free leaf-tips. 
Fic. 1.* 
Longitudinal section of the apex of a vegetative shoot of S. fruticosa, Linn., showing the 
development of the leaf-sheath with the elongation of the internodes. а. =aqueous tissue ; 
b. = palisade parenchyma; /.£. — leaf-tip ; f.t. — outgoing foliar trace; /s.—leaf-sheath. 
As the internodes of the stem elongate, the connate bases of the pairs of 
leaves elongate also, so that each internode is clothed with the basally 
developed leaf-sheath of the pair of leaves of the node immediately above. 
There is, of course, congenital union between the tissues of the stem and of 
the leaf-sheath, but it is always quite easy to trace the limiting layer f 
* Figs. 1, 2, 5 and 12 are drawn to seale by the aid of the camera lucida, 
T As will be shown later in the paper, the “limiting layer" is the endodermis, which can 
be readily traced from node to node. 
2в2 
