6\ Maslen . — The Relation of Root to Stem in Catamites. 
by whom they were given to me for examination. Some of the slides 
have now been incorporated in Dr. Scott’s collection and are indicated 
by the letter S in the following description ; the others, marked M, are 
now in my own collection. 
Description of the Specimens. 
The specimen shown in Plate I, Fig. i, was contained in the col- 
lection of the Chadwick Museum, Bolton, and for the photograph we 
are indebted to the curator, Mr. W. W. Midgley, F.R.Met.S. A series 
of twelve sections has been made from the specimen by Mr. Lomax 
(slides 1092-1103 S). 
It measures just over seven inches in length, and tapers at its lower 
end almost to a point, and so comes to resemble in form the familiar 
medullary casts of the branches of Calamitean stems. It is not, however, 
a mere medullary cast, as the sections which have been made from the 
specimen clearly show the internal structure of the wood. Passing right 
through the xylem from its inner border outwards are seen in the sections 
a considerable number of adventitious roots arranged in whorls, from four to 
six from a node. The arrows in the photograph indicate the position of 
these whorls of roots, each of which is visible on the outside of the speci- 
men as a distinct elevation. The lower tapering part of the stem is about 
three inches long, and on this portion the whorls of adventitious roots 
are crowded together. In the upper four inches there is only one whorl 
of roots. Some of the roots show an evidently fractured surface (see the 
middle node of the tapering part of Fig. 1), indicating that they have been 
broken off subsequently to fossilization. 
It would appear that we here have the lowest part of a main aerial 
stem of Catamites , obviously in a young condition from its comparatively 
small size. The way in which the root tapers below to a blunt point 
would indicate the absence of a persistent primary root and that all its 
roots were adventitious. Probably the lower tapering part and some of 
the stem above were embedded in the swampy soil in which the plants 
grew, and it was propped up by its whorls of adventitious roots in very 
much the same way as in some Monocotyledons at the present day. As 
it is known that Catamites was provided with an underground rhizome 
from which the erect stems grew, it is highly probable that our specimen 
was attached at its narrow end to such a rhizome. If so the attachment 
must have remained a small one. This is of course quite different from 
the familiar cases of the attachment of pith-casts of branches of stems or 
rhizomes by little more than points. Williamson long ago explained the 
latter by showing that, although the pith became very narrow at the 
junction of branch and stem or of one branch with another, the enclosing 
secondary wood became much thicker, so that the real attachment was 
