116 BOTANICAL GAZETTE [AUGUST 
their base with the inner bundles of the stem. The small bundles 
of the leaf trace come from branches of the peripheral bundles. 
They, as well as the central bundles, go with or without branching 
into the petiole, which is merely a continuation of the stem. 
In an elaborate discussion of the vascular anatomy of the 
Piperaceae, WEISS (19) deals with 11 species of Peperomia and 
8 of Piper, and draws the conclusion that in the Piperaceae there 
is a transition from the monocotyledonous to the dicotylenany 
type of bundle. 
By far the most detailed account is that of DE Bray (3). He 
used 4 species of Saururaceae; 16 species of Piper, 3 species of 
Artanthe, and 11 species of Peperomia. In Piper he found 2-4 
rings of bundles arranged in two systems, the peripheral and the 
pith systems. The peripheral bundles are of two sizes; the outer 
ring is completed by an interfascicular cambium; the leaf trace 
comes from a peripheral ring, which in the node below is a branch 
of the central bundles; the vascular supply of the axillary buds is 
from both peripheral and central bundles. He compares the 
families of the group, but shows no relationships. 
In Van TrEGHEM’s (17) work on the mucilage canals of Piper 
he describes in detail the stem of Piper nigrum. He found that 
there are two circles of bundles; that the pericycle becomes ligni- 
fied late in the growth of the stem; that the cambium for a long 
time cuts off segments only on the side toward the pith, and may 
cut off very late a few segments on the other side; that the mucilage 
canals vary in location with different forms and are not continuous 
through the nodes; and that the canal of the petiole is not con- 
tinuous with that of the branch. 
The present study of Piper methysticum was taken up with the 
idea of giving a modern interpretation to the vascular structure, 
and to ascertain whether the stem keeps pace with the gametophyte 
of the group. 
Material 
I am indebted to Dr. W. J. G. LANnp for the material for this 
study. It was collected on the Island of Tutuila, Samoa (fig. 1). 
The plant is a native of the South Sea Islands, and is commonly 
