OP THE FOSSIL PLANTS OF THE COAL-MEASURES, 
517 
bed near Halifax, from which bed, as is also the case at Oldham, I have obtained my 
principal specimens of these Gymnospermons stems. They have obviously been drifted 
fragments. The pith, a, consists as usual of large-celled parenchyma. The prosenchy- 
matous woody tissues, c, c, c, are arranged in their normal manner. The pith is pro¬ 
longed outwards at b and b ; its coarse, parenchymatous cells rapidly developing into 
radially elongated prosenchymatous ones, as the two medullary outgrowths proceed 
outwards. In the early part of their course these outgrowths do not appear to be 
accompanied by any of the woody fibres, c, through which they pass ; but more exter¬ 
nally, as at c, there are clear indications that many of these fibres are deflected 
outwards in the same direction as the pith-cells. This specimen leaves no doubt in 
my mind that these pairs of fibro-cellular bundles are sometimes destined to supply 
branches, which must have sprung from the stem in pairs. Since no such dual 
arrangement of either leaves or branches is seen in M. Grand-’Eury’s fine examples 
of Cordaites, which plants that author regards as identical with the Dadoxylons, this 
want of harmony between his specimens and mine strengthens my conviction already 
expressed elsewhere,* that our English Dadoxylons cannot, as yet, be identified with 
the French examples of Cordaites. 
That pairs of vascular bundles given off from small twigs may have proceeded to 
leaves, as suggested in my eighth memoir (Joe. cit., p. 231), is possible, and does not 
militate against my explanation of the morphology of the specimen just described, since 
the primary orientation of its branches must have been from the axils of corresponding 
leaves. 
In the memoir, Part VIII., I described the organization of the seed to which I gave 
the name of Lagenostoma oroides. In the specimens of that seed which were obtained 
from the Oldham deposits, the outermost layer of the testa was converted into an 
almost structureless carbonised substance ( loc. cit., Plate 10, figs. 60, 62, and 71a). In 
figs. 65 and 66 of that memoir there is also observable a thin layer of tissue external 
to the layer, e, or what I have designated “ the canopy,” or folded tent-like prosen¬ 
chymatous membrane which encloses the lagenostome, or pollen-chamber, whilst in 
fig. 69, a, ci, I showed that the testa split into two layers, the inner one of which is 
I believe identical with those seen in figs. 65 and 66. 
Mr. Spencer has sent me a slightly oblique longitudinal section of one of these 
seeds from the Halifax bed, which throws additional light upon its structure. Fig. 
61 represents this specimen enlarged 18 diameters, in which a is the outer layer of 
the testa, b , b' portions of the canopy, c' the wall of the lagenostome, and g the 
embryosac. 
Fig. 62 represents a portion of the outer layer of the testa, 61, a, enlarged 200 
diameters. It consists wholly of sclerenchymatous cells, of which the central cavities 
are nearly obliterated owing to the thickness of the ligneous deposits lining their cell- 
walls. A regular superficial layer of nearly cubical cells, a", constitutes the external 
* ‘Nature,’ June 21, 1877, p 138. 
3 X 
MDCCCLXXX, 
