Dischidia rafflesiana ( Wall .). 263 
and did not begin to taper off regularly for about 4 cm. from 
its base. At this point the internal phloem disappeared, 
becoming confluent with the normal external phloem. It was 
also absent at the base of the root. 
We will describe the anatomy in detail in one case, as both 
the roots showed similar variations in structure. 
In this case the internal phloem makes its appearance, if we 
trace the structure from base to apex, before the root becomes 
free from the parenchyma of the petiole. It is continuous 
with the normal phloem, which is alone present at the actual 
base of the root, and through this, with the normal phloem of 
the stem. The anomaly of the root is therefore a local one, 
as its medullary phloem has no direct communication with 
that of the stem. 
At 1 mm. from the apparent insertion of the root (i.e from 
the point where it becomes free from the petiole) the structure 
has become very complicated. The tetrarch xylem here forms 
four distinct masses, each surrounded by a ring of phloem, the 
external elements of each ring being at this stage obliterated 
(see Woodcut A). 
Woodcut A. 
From transverse section of pitcher-root i mm. below apparent insertion : 
px , protoxylem ; ph , phloem. xi2o. 
