^jZmL.Srris^^^^^^^ PROCEEDINGS OF SOCIETIES. 323 
seen in Mr. Binney's Calamites, to the reticulated one of the author's 
specimens. All Mr. Butterworth's sections afforded distinct evidence 
of the existence of medullary rays, even when the vascular tissue con- 
sisted of barred vessels ; but the latter examples do not exhibit the 
large verticils of medullary radii characterizing the author's genus 
Calamopitus. Mr. Butterworth's cabinet had further furnished the 
author with the cone of Calamopitus, which proves to be much larger 
than Mr. Binney's cones of Calamodendi'on, as well as to exhibit 
numerous other distinctive features. The author proposes to make 
this cone the subject of another memoir. It is a true Cryptogamic 
spore-bearing organ, the spores of which resemble the tetra-spores of 
the Rhodospermous Fucoids in being lodged each in a separate cell. 
They exhibit no traces of Equisetiform elaters. 
The additional evidence thus obtained convinces the author that 
in its structure and growth the stem of the Calamite has been exoge- 
nous, but the structure of the cone proves that the plant has not been, 
as Mr. Adolphe Brongniart supposes, a Gymnospermous exogen. It 
has combined the woody cylinder of an Exogen with the fructification 
of an Acrogen, a combination that has no existence amongst living 
plants, thus establishing a transition, through the modified Coniferce 
of the coal measures known as Dadoxylons, from the Cryptogamic to 
the Phanerogamic forms of vegetation, meriting the attention of Mr. 
Darwin. The author pointed out that the Dadoxylons themselves 
were not true Coniferce of the modern type, since none of their stems 
exhibited the true glandular pleurenchyma characteristic of that type, 
lie also reviewed the attempts made to "restore" the Calamite, ob- 
jecting to them as premature and, consequently, unsuccessful ; and, 
further, gave reasons for believing that the fluted stems of Calamites 
bore verticils of slender branches and not merely of leaves. In con- 
clusion, he called attention to the wonderful penetrating power of the 
cylindrical rootlets of Stigmaria, revealed by Mr. Butterworth's fine 
sections. They seem to have found their way into everything that 
presented the slightest trace of a penetrable opening or a cavity ; and 
in one instance, one rootlet had forced its way into the interior of 
another in every respect, but size, like itself. 
Ordinary Meeting, April 6th, 1869. E. W. Binney, F.E.S., F.G.S., 
Vice-President, in the chair. — Professor W. C. Williamson, F.E.S., 
gave an account of the present state of knowledge in reference to the 
structure of the gizzards and teeth of the Rotifera. After pointing 
out the discrepant accounts given by various writers on the subject, 
including his own examination of the teeth of Melicerta, he showed 
how all appeared to have failed in deciphering their anomalous 
appearances with perfect accuracy. He then directed attention to 
the very successful investigations made by the Rev. the Lord Sidney 
Godolphin Osborne, respecting the teeth of Rotifer vulgaris ; and 
having not only studied with care his Lordship's preparations, but 
also compared them with his own examinations into the same animal, 
he was prepared to endorse the chief conclusions at which his 
Lordship had arrived. This dental organ consists primarily of two 
slightly arcuate jaws, broad at their upper extremities, and narrow and 
