OF THE WOODY ZONE IN CALAMITE. 169 



the tissues^ referred to ; but none of his figures correspond 

 exactly with the vessels of my plant, fig. 163 E alone ex- 

 hibiting an approach to a resemblance. 



Be this as it may, we now have suggested to us the pos- 

 sible existence of three types of Calamodendron, in each 

 of which the stem consists of woody wedges, disposed 

 vertically around the pith from which their component la- 

 minae radiate, and which are separated from one another by 

 alternating vertical cellular masses either of parenchyma or 

 prosenchyma, which latter connect the pith with the bark. 

 But if the descriptions of Mr. Binney and Mr. Carruthers 

 are correct and generally applicable, it is also obvious that, 

 though constructed on a common plan, important differ- 

 ential characters separate two of the types from the third. 

 In Mr. Binney^'s plants the woody wedges are exclusively 

 composed of scalariform tissues, and appear to contain no 

 true medullary rays. On this point Mr. Carruthers speaks 

 strongly, and relies upon the fact as one evidence of the 

 Cryptogamous character of these fossils f ; and Mr. Binney 

 does not appear to diff'er materially from Mr. Carruthers. 

 He figures in his plate 3. fig. 6 what he terms ^*^ medullary (?) 

 bundles/^ but these are the representatives of my pros- 

 enchymatous tracts, and not of the muriform medullary 

 rays. 



The thick radiating cellular laminae separating the woody 

 wedges in Mr. Binney^s specimens consist of ordinary par- 

 enchyma. In Unger^s Calamitea the woody wedges con- 

 sist, as in Mr. Binney^s examples, of scalariform tissue 

 (vaisseaux rayes) ; but these vessels are separated by " des 

 rayons medullaires tres-etroits, d^un seul rang de cellules, 

 et peu etendus en hauteur " (Tableau des genres de Ve- 



* Loc. cit. figs. 162 c, d, and 163 E. 



t " On the Structure and Affinities of Lejpidodendron and Calamites, by 

 W. Carruthers, Esq., F.L.S." Seemann's Botanical Magazine, Dec. 1866 ; 

 see also Journal of Botany, Dec. 1867, "On the Structure of the Fruit of 

 Calamites.'" 



