5 § 
Eric Drabble. 
At a slightly higher level the xylem groups are found to have 
approached nearer to the centre of the axis, while here and there 
traces of the protoxylem groups are seen to occupy a position near 
the periphery of the cylinder, widely separated from the more 
centrally placed main groups. These main groups are continuous 
with the “ fused ” metaxylem groups of the lower portion, and 
consequently with the individual xylem groups of the typical root, 
than which they are necessarily fewer in number—some six or 
Fig. 5. 
Series of transverse sections illustrating 
transition in Phoenix dactylifera. 
seven being usually present. At about this level (Fig. 5 iv.) 
certain small elements appear in the xylem groups, which certainly 
seem to be protoxylem. The whole of the group is now composed 
of somewhat scattered elements, and these protoxylem vessels are 
more or less centrally placed. A little higher up the axis this 
protoxylem is found in an endarch position, and almost immediately 
above this the cotyledon bundles, of which there are six or seven, 
are seen running in an almost horizontal direction radially, 
(Fig. 5 v.) Each cotyledon trace is continuous internally with 
part of one of the axial xylem bundles. The rest of the xylem of 
the axial bundle is continued upwards into the plumule, which still 
shows very little differentiation of its tissues. The lower ends of 
the bundles—as yet in the procambial condition—supplying the first 
