FROM THE LOWER COAL-MEASURES. 47 
ART. xus os ee eS ue S a Pw. gl etre van VII. 
EM? oos ec Te pO P RACER PREIS poo. Sie Dea VIII. 
Gap. 
Miss Stopes- somi 41.7 2003 5 1 4 v X Ro S celu IX. 
Gap, corresponding to the 23 longitudinal sections “ A-W.” 
Pror. Weiss s NAME 21m VONT ST ESTA X. 
RU Tuc qv V qure, XI. 
epe EST AN ies e ae VOV oe XII. 
"CU EDEN I NE uu oU VL ML RE a XIIH. 
"B7 eer imi ee wi misa aoee a eai v bo n a XIV. 
WA xe T oDapcep M o wr NT ET MT E ior XV. 
Mi SAMI 6 RECN 2. cx as eg MI RUP TCR ol XVI. 
Small gap, corresponding to Prof. Jackson's transverse section. 
M xls PA XVII. 
An oblique section was eut from the end beyond No. XVII. 
The longitudinal sections in the University College Collection were cut parallel to the 
short diameter of the stele, while those lettered A to W, chiefly in my own collection, 
were cut in the direction of its long axis. 
Mr. Lomax deserves high praise for the admirable manner in which the sections have 
been cut, so as best to exhibit the structure of the whole specimen. 
General Structure. 
The structure of the stem as a whole is best shown in Prof. Weiss's transverse section, 
which is the most complete (Pl. 7. fig. 5). This section is No. X. from below in the 
series; it was probably cut at a point about two-thirds of the length of the fragment 
from its basal end. 
The peripheral tissues are preserved for a considerable part of the circumference, 
though destroyed in places, and enough remains to give a fair idea of the general 
contour of the stem. On the right? above, is a marked protrusion, which must probably 
be regarded as a leaf-base. It can be traced through the whole series of transverse 
sections, and though a few additional bundles enter it, it shows no signs of becoming free. . 
It appears, then, that the leaf-bases were decurrent for a long distance, as in Medullosa 
anglica (Scott, 1899, p. 84, pl. 9). There are no means of distinguishing between the 
cortex of the stem and that of the leaf-bases, and it is probable that we must regard the 
latter as completely investing the surface. It is unfortunate that no petiole becomes 
free from the stem within the limits of the specimen. This fact, together with the 
slowness of the anatomical changes, to be described below, certainly indicates that the 
stem must have been of considerable height. 
The external cortex, wherever it is preserved intact, is of the familiar type of 
* Myeloaylon Landriotii,” i. e., it is practically identical with that of a Medullosa, — 
as M. anglica (Pl. 9. fig. 16) (Scott, 1899, pl. 5. phot. 5; por i ; — 
sections show that the hypodermal strands of selerenchyma preserve a straight course, 
with little or no anastomosis. | DS ! 
The cortex within the hypoderma. also has a Myeloxylon character, Pom à 
: K 
