232 
PROFESSOR W. C. WILLIAMSON ON THE ORGANIZATION 
had been split by means of a wedge in a plane at right angles to the direction of the 
imbedded branch. Hence we have every reason for continuing to class Dadoxylon 
amongst the Gymnospermse. I refrain from attempting to assign specific names to any 
of these fragments, being unable to discover any distinctive features whereby to charac- 
terize them. 
The larger branches found in the Ganister-beds, associated with Goniatites, rarely 
display any trace of bark, and what little does exist is much disorganized — an additional 
indication that they have been drifted from a distance and long exposed to the action of 
Water. 
Seeds . — Most of the writers who have illustrated the Flora of the Coal-measures have 
described some form or other of what they supposed to be seeds ; but nothing was known 
of the internal organization of any of these objects until Dr. Hooker and Mr. Binney 
published their memoir on Trigonocarpon* . In this memoir the Trig onoear yon 
described, which appears to have been the T. olivceformce of Lindley and Hutton f, is 
shown to bear a close resemblance to the true drupaceous seeds of Salisburia adiantifolia. 
Though no further light was thrown upon their internal organization, numerous addi- 
tional forms of Carboniferous seeds were described and figured, especially from the 
Coal-formations of the New World, by Mr. Newberry J. This scanty knowledge was 
suddenly increased through the discovery of a thin bed of silicified rock at St. Etienne, 
one of the many results of the important researches of M. Grand’Eury. This deposit 
abounds in fossil seeds, many of them being of considerable size and having much of 
their structure exquisitely preserved. Twenty-four species of these, distributed through 
seventeen genera, have been recently described by M. Brongniart§. In this important 
memoir, which was read to the Academy of Sciences in August 1874, the veteran author 
merely gives small outlined sketches of the various seeds; but it was his intention to 
make them the subjects of a separate volume, in which the minuter details of their 
organization would have been elaborately illustrated. Unfortunately his recent death 
has robbed the Geological world of what would have been one of the most important 
contributions yet made to Carboniferous literature. 
M. Brongniart unhesitatingly determined that his specimens are true seeds referable 
to the Gymnospermous group of plants, though he discovers in them numerous secondary 
modifications which are not seen in matured recent Gymnospermous seeds. His remarks 
on one of these modifications are so important that I quote them here : — 
“ Dans plusieurs de ces graines, cette extremite (superieure) du nucelle, que j’ai 
* “ On the Structure of certain Limestone Nodules enclosed in seams of Bituminous Coal, -with a Description 
of some Trigonocarpons contained in them.” By Joseph Dalton Hooker, M.D., and Edward William Binney, 
Esq. Phil. Trans, vol. cxlv. part i. p. 149, 1855. 
t ‘ Eossil Flora,’ iii. t. 222. figs. 1, 3. 
t ‘ Report of the Geological Survey of Ohio,’ vol. i. part ii. Palaeontology. “Descriptions of Eossil Plants,” 
hy J. S. Newberry. 
§ “ Etudes sur les Graines fossiles trouvees a l’etat silicifie dans le Terrain Houiller de Saint Etienne,” par 
M. Ad. Brongniart. ‘ Annales des Sciences Naturelles,’ Botanique, 5 e serie, tome xx. 
