244 
PEOFESSOE W. C. WILLIAMSON ON THE OEG-ANIZATION 
not been able to satisfy myself whether the lower layer of the nucular membrane (f) 
passes under the cellular mass (p) or whether it merely becomes merged in its cells; 
but I think that the former is its real condition. 
Fig. 80* is a second longitudinal section made a little on one side of the last. To the 
left of the figure the nucular membrane ( f) is closely united to the inner surface of the 
testa (a). Above the nucleus the nucular membrane (f) still subdivides into the two 
layers the former of which still forms a dome (c), whilst the latter is in contact 
with the testa. But the little point of parenchyma (fig. 80, p) is no longer seen, the 
section having passed on the outer side of it. In the interior of the nucleus (n) is some 
carbonaceous matter which appears as if composed of remnants of the perispermic cells. 
Fig. 81 is a yet more lateral or tangential section which corresponds with the last, 
except that having passed on the outer side of the dome-like space (fig. 80*, c) it has 
intersected the shelf-like extension of the nucular .membrane ( / '), which here stretches 
across the seed in a straight line, whilst the upper part (f") is in the closest connexion 
with the testa a'. 
Fig. 86 represents a vertical section of what I believe to be a second example of this 
species. It has lost some parts of its testa (a), but on the other hand it adds somewhat 
to our knowledge of the arrangement of the membranes near the apex of the seed. The 
nucleus (n) is large, and is full of minute dark points, which at the first sight resemble 
microspores, but which I believe are merely remnants of the cells of the perisperm. 
At one point near the centre of the seed a mass of these cells is aggregated into a dark- 
coloured mass. Towards the lower part of the seed we only see traces of one membrane 
(f) investing the nucleus, and which I presume consists of the two membranes (f & g) 
of fig. 80 united into one. Above the apex of the nucleus we find this membrane 
splitting, like the membrane f in fig. 80, into the two portions f' and/”", which follow 
the same course as in the latter figure. But the small mass of cellular parenchyma (p) 
is now larger than it is in fig. 80, besides which we here find on each side of the seed a 
third membrane which has evidently followed the curvatures of the inner surface 
of the testa, and though now slightly detached to the left, its apex has evidently fitted 
into the base ( d ) of what has evidently been the micropyle. These conditions clearly 
demonstrate, what my own specimen failed to do, that the parenchyma (p) occupies 
the interior of a lagenostomal cavity. In all probability the peculiar cavity ( c ) was 
originally occupied by a mamillated prolongation of the nucleus. Fig. 86 clearly 
demonstrates that the nucleus entirely filled the cavity enclosed within the membrane 
f of fig. 80, so far as the sides and base of the seed were concerned, and most probably 
also at its apex. If so, the lagenostomal parenchyma ( p ) would rest, as in Lagenostoma 
ovoides, directly upon the apex of the nucleus. The mean length of Conostoma oblonga 
has been about T8 to ‘2. 
The rich deposit at Burntisland has hitherto only furnished me with good examples 
of one seed, which appears to be of the same generic type as the last ; I propose for it 
the name of Conostoma ovalis. Fig. 82 is a vertical section through the centre of one 
