202 
Hill and de Fraine. — On the 
Pinus australis. 
Series A. Nine cotyledons were present, 1 the bundles of all of which 
showed division of the bast and rotation of the xylem for the greater part 
of their length. Thus, at about the level of the cotyledonary node, there 
was in each seed-leaf a resin duct occupying a central position towards the 
upper surface; immediately ventral to this canal the protoxylem was 
situated, while on each side of the resin tube were the two groups of phloem 
bounded by metaxylem (Diagram 4, Fig. 1). The appearance of these 
strands within the axis would warrant the assumption that a 9-arch root 
would result, for the contiguous half-bundles have only to fuse to bring 
about the typical root-structure. But on tracing the bundles downwards, 
it was found that a 7-arch root obtained, a result brought about by the 
obliteration of the half-portions of four bundles, and the fusion of the 
neighbouring protoxylems. This is illustrated inthe accompanying Diagram 4, 
Figs. 2 and 3, where p. indicates the phloem ; mx. represents the metaxylem, 
and px. stands for the protoxylem of the bundles of the eighth or ninth 
cotyledon. It will be seen that the vascular tissue of cotyledon 8 has two 
groups of phloem, two masses of metaxylem, and one collection of proto- 
xylem elements situated on the inner side of a resin duct (r.d.). The 
same applies to seed-leaf 9. On tracing these structures downwards, the 
metaxylems pass more towards the centre of the axis, leaving the proto- 
xylems fully exposed, any small amount of metaxylem, which would other- 
1 According to Masters (loc. cit.), 7-10 cotyledons. 
