442 Scott.—The Structure of Mesoxylon multirame. 
Another point is the relation of the axillary stele to the subtending 
leaf-trace. The stele as it passes in through the cortex and phloem makes 
an acute angle with the vertical, and consequently is cut almost transversely 
in transverse sections of the main stem. Immediately on reaching the 
secondary wood, however, its elements take an almost horizontal course, 
as shown in PI. XI, Fig. 3. This is no doubt (like the corresponding curva¬ 
ture of the trace-bundles) an accommodation to the secondary growth of 
the main axis. As already mentioned, the wood of the axillary stele is 
connected on either side with the wood on its flanks ; sometimes the stele 
is so much affected by these lateral connexions as to appear split into 
two lateral halves (cf. Maslen, 1911 , p. 407). 
Another interesting point is the relation of the axillary stele to the 
primary bundles of the main stem. This is difficult to make out in a stem 
which has already undergone a good deal of secondary growth. But, in 
favourable cases, strands of primary, spiral or scalariform, elements can be 
seen curving to the right and left at the inner end of the axillary stele, as if 
to join the adjacent leaf-trace bundles on either side (cf. PI. XIII, Fig. 14). 
It appears, then, that the axillary stele in its vascular connexions follows 
the Coniferous type ; it is not directly connected with its own subtending 
trace, but with the trace-bundles to the right and left., between which its 
own trace passes out. The same relation was found by Bertrand and 
Renault in Poroxylon ( 1886 , pp. 29 6, 300-3, Fig. 199), where the insertion 
of the axillary branch takes place on the two bundles which enclose between 
them the outgoing leaf-trace. 
In tracing the connexions of the bundles I have, for obvious reasons, 
confined my attention to the xylem. 
The Axillary Shoots. 
The axillary shoots are a most characteristic feature of the species and 
suggested the choice of the specific name multirame * As already mentioned, 
every leaf, through a considerable length of stem, bears a shoot in its axil; 
in the upper part of the specimen, however, these shoots are undeveloped. 
The type-specimen only shows the bases of the axillary shoots. We 
find these well preserved up to the point where they are just free from the 
main stem ; beyond that, except for some doubtful fragments, they cannot 
be recognized. The best section for them is 2335, in which 3 are shown, 
which are nearly or quite free from the stem (see photograph, PI. XI, Fig. 2). 
The best preserved is shown in detail in PI. XIII, Fig. 22. At this level 
the shoot is absolutely leafless ; its outline is more or less elliptical, with 
the long axis tangential to the parent stem ; the dimensions in this case 
are about 6x3 mm. The stele has the remarkably flattened form to which 
attention has already been called. Its dimensions are about 3*5 mm. long 
by 0-3 mm. broad. The detached portion at one end might be taken for 
