352 MR. 8. LE M. MOORE’S STUDIES 
apostrophe, The large leaves of S. Martensii are covered on the 
upper face with an epidermis of five-, six-, or even seven-sided 
cells with wavy borders, the angles frequently not well indicated. 
Similar cells are continued over the single centralrib. The cells, 
isodiametral or nearly so in the distal and middle parts of the 
leaf, are at the proximal end somewhat elongated in the direction 
of the long axis. The fore edge is, for the greater part of its 
course, oceupied by cells many times longer than broad; these 
may sometimes be studded with small bosses upon the side walls 
or upon the free (superficial) wall as well. There may be as 
many as four or five rows of these marginal cells, which are 
wanting at the leaf's hinder edge, the isodiametral cells under 
these circumstances running up to the edge to abut on a single 
row of narrow cells. At either edge some of the marginal cells 
grow out to form a tooth with lumen continuous with that of the 
parent; these teeth are longest near the base of the fore edge, 
and most numerous near the leaf's apex, where, indeed, nearly 
every marginal cell is dentiferous. On the underside, the cells 
of the proximal three-fourths are much longer than those of the 
upperside, except over and near the rib, where not much elon- 
gation is seen. The area of narrow bossed cells is usually deeper 
here than on the upperside, and it may be still further broadened 
in places by the apposition of wider cells with bosses upon their 
walls; the wider type of bossed cell may occur here and there 
among the ordinary cells of the underside. Stomata are placed 
upon the lower face on or close to the rib, their number ranging 
between one and two hundred: a few stomata are also found 
upon the hinder edge, rarely towards the distal end of the fore 
edge as well. In the early stages of growth the small leaves 
completely overlap the large ones, and the latter each other; but 
as the axis lengthens the large leaves diverge, each being now 
overlapped anteriorly by the leaf in front and similarly covering 
its predecessor; afterwards only the proximal half of the fore 
edge is covered and at length the leaves get quite clear; the 
slight obliquity of these leaves is due to forward extension of the 
leaf-tissue at the proximal part of the fore edge, a region of the 
leaf where the cells are several times longer than broad. The 
upper leaves, at first closely imbricated, are soon free from each 
other except for slight overlapping at the side and base, which 
afterwards disappears in consequence of the elongation of the 
stem. These leaves are more oblique than the larger ones, the 
