370 PROP. W. C. WILLIAMSON ON THE 



ridial organs^ and that its supposed anthers are filled with 

 true pollen-grains. To this I make but two answers: — 

 first, even supposing it true that these objects were polleni- 

 ferous structures, we have no evidence whatever that 

 they belong to Calamodendron. Their doing so is a pure 

 assumption. But even could it be proven that they were 

 so related, I deny altogether that these objects are either 

 antheridial or polleniferous. 



My friend Mr. Cash, of Halifax, has received from 

 M. Renault two sections of these objects, which he has 

 kindly allowed me to examine. These sections being 

 inscribed, in the handwriting of the French savant, " Epi 

 de Calamodendron, Pollen divise,^^ there is no doubt as to 

 their being really the objects to which I have just referred. 

 I have no hesitation in saying that these are nothing more 

 than sections of a very distinct form of Calamostachys, of 

 which the supposed pollen-grains are merely the spores, 

 enclosed within their mother-cells, exactly as I have 

 figured similar ones from the sporangia of Calamostachys 

 Binneyana, in my memoirs " On the Organization of the 

 Fossil Plants of the Coal-measures," Phil. Trans, pt. ii. 

 plate 15, fig. 17. From all these combined facts I once 

 more conclude that Calamodendron striatum is an Equise- 

 tiform plant, closely allied to the true Calamites*. 



INDEX TO THE PLATES. 

 . Plate XIV. 

 Fig. I. Inorganic cast of the medullary canal (fig. 2, a) of a Calamite, with 

 the transverse nodal constrictions, a, produced by the projection 

 inwards of the nodal tissues at that point. The longitudinal 

 furrows produced by the similar inward projection of the inner 

 angles of the longitudinal vascular wedges (fig. 2, c). 



* I need scarcely remind Palseo-botanists that in 1881, Vom c. M. D. 

 Stur, of Vienna, arrived at the same conclusion, in his valuable memoir 

 " Zur Morphologie der Calamarien." Aus dem Ixxxiii. Bande der Sitzb. 

 der k. Akad. der Wissensch. I. Abth. Mai-Heft, Jahrg. 1881. 



