or THE EOSSIL PLANTS OF THE COAL-MEASURES. 
239 
remained in the cabinet of my equally valuable auxiliary Mr. Nield, and this he, too, 
resigned to the grinding-wheel. Nothing could be more satisfactory or rewarding to so 
true a lover of science than the results of this devotion. Unfortunately Mr. Nield had 
ground away a little of the extreme micropylar extremity of his specimen before he 
became aware of its value. When it came into my hands the ground extremity 
exhibited the appearance seen in fig. 71, which, enlarged 15 diameters, reveals the 
exquisitely symmetrical arrangements characterizing the membranes in the lagenostomal 
region when undisturbed by pressure, mineralization, or the shrivelling of the tissues 
prior to fossilization. This seed was wholly detached from the matrix, which had, as is 
so usual, carried away with it the greater portion of the testa. Nevertheless the outline 
of its inner surface a is perfectly preserved. Within this testa we have the crenulated 
outline e, which represents the transverse section of the canopy, consisting of ten crenu- 
lated curves, the rounded concavities of which face outwards, where they are separated 
from each other by sharp projecting folds of the membrane, arranged in a regularly 
radiating order, but the angles of which do not reach the testa. Within this fluted 
canopy we have the upper part of the lagenostome ( d ), also fluted in correspondence 
with the canopy, though the inflexions of this membrane are much less prominent than 
are those of the canopy itself. 
Fig. 72 is a second transverse section of the same seed made across the broadest part 
of the lagenostome, enlarged 30 times. At a we have a portion of the testa. At e is 
the canopy exhibiting the regular crenulated outline already described ; we here see 
that it presents a sharply defined margin at its inner border, whilst externally it has a 
torn and shredded aspect, indicating a former attachment to the inner surface of the 
testa a. This attachment is further indicated by the innumerable delicate fragments of 
cellular tissue which occupy the concavities of the folds of the canopy. In the centre 
of each of those concavities there is a dark spot ( n ). I cannot detect at these points any 
specialized structure beyond traces of a few dark-walled cells, and it seems extremely 
probable that these may have been elements left behind for some purpose by the 
transverse bars {a') seen in fig. 57. On the opposite side of the seed ( e ') the regular 
crenulations of the membrane forming the canopy have disappeared, probably as the 
result of shrivelling prior to mineralization. At c we have a section of the wall of the 
lagenostome. We have already seen from fig. 70 that it was composed of prosenchy- 
matous cells. We now find that it consists of a single layer of such cells. 
Fig. 74 represents a few of the prosenchymatous cells composing the canopy, as 
seen in the specimen fig. 70. In fig. 72, c , these cells are intersected transversely; at 
c, c' we see indications of the regular crenulations which originally characterized this 
lagenostomal membrane, but which have here in a great measure disappeared, through 
shrivelling ; mineralization also has somewhat modified its normal aspect at c". 
Near the centre of the lagenostomal cavity we have a small portion of the parenchy- 
matous tissue ( [h ) seen in the same position in so many of the other sections, only 
here it is reduced to an exceedingly small amount. Scattered throughout the open 
2 l 2 
