408 
ON THE FOSSIL PLANTS OF THE COAL-MEASUKES. 
Plate XXX. fig. 36. Transverse section of a stem, giving off a lateral pseuclo-vascular 
bundle, probably supplying an adventitious root, magnified 
6 diameters. 
33 
33 
33 
33 
33 
33 
fig. 
37.1 
fig. 38. 
fig. 39. 
fig. 40. 
fig. 41. 
fig. 42. 
Successive series of transverse sections of one stem, about 2 
inches long, showing the changes in the relative positions of 
the vascular bundles at various heights of the stem : mag- 
fied 10 diameters. 
„ % 43. 
„ fig. 44.; 
Plate XXXI. fig. 45. Vertical section of the middle and outer layers of the bark of a 
young twig, magnified 96 diameters. 
Plate XXVIII. fig. 46. Transverse section of a young twig, magnified 24 diameters. 
Plate XXXI. fig. 47. Longitudinal section of the twig fig. 46, magnified 24 dia- 
meters. 
„ fig. 48. Restoration of the young stem of Lyginodendron Oldhamium , 
cut open to show the several structures. 
„ fig. 49. Restoration of the stem of Heterangium Grievii, cut open as in 
fig. 48. 
Throughout the entire series of the preceding figures, the same letters are employed 
to indicate what appear to be homologous tissues and organs. They are also employed, 
as far as possible, in the same way as in my preceding memoirs of this series. 
a. Medullary axis. 
b. Medullary cells. 
c. Medullary vessels. 
d. Ligneous zone. 
e. Ligneous zone, vessels of. 
f. Medullary rays of ligneous zone. 
g. Innermost bark -layer, parenchymatous. 
h. Middle bark-layer, parenchymatous. 
I,:. Prosenchymatous bark. 
l. Subepidermal parenchyma. 
m. Foliar (?) bundles of vessels. 
7i. Root-bundles ? 
x & y. Branches. 
z. Stem-bundles. 
