144 Jeffrey. — Infranodal Organs in 
description of the newly discovered root-bearing stems of 
Calamites in his possession. 
In Equisetum , as is well known, the branches occur imme- 
diately above the medullary rays, and since the roots in this 
genus are always attached to the bases of the branches, they 
consequently occur in the same position. In Equisetum hiemale 
it not unfrequently happens, in the case of deep and vigorous 
rhizomes, that the rhizophorous branch almost completely 
aborts, and the single very large root, which it bears, is attached 
directly to the supranodal wood, thus lying immediately over 
the large ramular medullary ray. What occurs exceptionally 
among the Equiseta seems to have been the rule in the case 
of the Calamites ; for in the latter it is quite unusual to find 
a branch with roots attached. Weiss figures only one example 
of this sort. 
Photograph 2, PI. VIII, represents a tangential section 
through the wood of Polygonum amphibium in the nodal region. 
Above is to be seen the parenchymatous medulla of a branch, 
and immediately below the latter is a lenticular organ with 
a leaf-trace causing a toothed projection on its inferior margin. 
In nearly the same horizontal plane on the left is another 
lenticular organ (infranodal canal). In the lower part of the 
photograph a root is seen in cross-section. So far as the 
writer has been able to observe, the roots of the Dicotyledons 
have no fixed position in regard to either the nodes or the 
branches. The relation of the branch to the infranodal organ 
in the Dicotyledons exactly simulates the relation of the 
roots to the similar organs of the Calamites ; for in the latter 
the roots occupied the same position as branches just as they 
do exceptionally in Equisetum hiemale . 
The results of the present investigation may be summarized 
as follows : — 
1. Some of the existing figures of the surface of Calamitean 
stems are inverted and others are misinterpreted. 
2. The infranodal organs of Williamson were not rhizo- 
phorous. 
