118 ; BOTANICAL GAZETTE [AUGUST 
the nodes are swollen and marked with several distinct rows of 
spots; the internodes are 5-9 cm. long and when young are covered 
with dense rows of hairs, giving a ridged appearance; the older 
internodes are smooth but spotted. 
The younger stems and nodes were cut in paraffin at’ 25-30 p 
and complete series obtained. The largest stems and nodes were 
treated with hydrofluoric acid for one week and then sectioned at 
30-50 uw with a sliding microtome, in this case also the series being 
complete. The safranin Lichtgriin stain was used. 
Origin and course of stem bundles 
The stem of Piper methysticum contains at maturity three 
rings of bundles, one peripheral and two within the pith, the bundles 
being foliar. The terminal bud is enveloped in the sheathing 
base of the youngest leaf. In some cases a bud was found within 
the sheath of a single leaf with as many as 3 leaves, each of which 
was inclosed in the base of the petiole just beneath it. 
The leaf primordium appears on the stem tip early and forms 
about it a semicircle, and 5-7 procambial strands are soon differ- 
entiated. These connect with the first strands of the stem (figs. 
2-4, j-p). Strands j-p are the strands of the youngest leaf 
(node 1); & is the first to be differentiated; 7 and / follow quickly; 
o and p come last. The bundles of the second leaf (node 2) are 
represented by the series ai. At node 1 the stem contains a 
single row of scattered bundles. These bundles (j—p) become the 
inner bundles of the stem at node 2, and a-7 of leaf 2 become the 
peripheral bundles (fig. 5). Through the following internode 
these two sets of bundles run approximately parallel and become 
the inner rings of the next node (node 3, fig. 6). The union of the 
two inner rings takes place here. Five methods of joining were 
observed in the case of the undifferentiated strand: (1) two strands 
from the same ring may join (fig. 8, /m); (2) two strands from 
different rings (fig. 7, ak); (3) one strand may divide and join 
a strand of a different ring (fig. 7, g'p); (4) two strands from the 
same or different rings may unite and then join a branch of a strand 
from either ring (fig. 9, efg, ino); (5) three strands may join, the 
result of this, for a short time, being a single inner ring (figs. 9, 
10, dlm). 
