Organisation of Fossil Plants of the Coal-Measures. 117 



February 8, 1894. 



Sir JOHN EVANS, K.C.B., D.C.L., LL.D., Vice- President and 

 Treasurer, in the Chair. 



A List of the Presents received was laid on the table, and thanks 

 ordered for them. 



The following Papers were read : 



I. "Further Observations on the Organisation of the Fossil 

 Plants of the Coal-Measures. Part I. Catamites, Calamo- 

 stachys, and Sphenophyllum." By W. C. WILLIAMSON, LL.D., 

 F.R.S., Emeritus Professor of Botany in the Owenp College, 

 Manchester, and D. H. SCOTT, M. A., Ph.D., F.L.8., F.G.S., 

 Honorary Keeper of the Jodrell Laboratory, Royal Gardens, 

 Kew. Received December 30, 1893. 



(Abstract.) 



1. Calamites. The first part of the paper gives a detailed account 

 of the vegetative structure of Calamites, on the basis of a renewed in- 

 vestigation, in which special attention has been directed to develop^ 

 mental questions. 



The petrified specimens which have formed the chief material for 

 our observations have their structure preserved in great perfection, 

 and it has been possible to make a thorough study of their organisa- 

 tion at various stages of development. 



The primary structure of the young stem, before growth in thick- 

 ness has begun* bears a striking resemblance to that of Equisetum. 

 The stem was jointed, with a whorl of leaves at each node. Although 

 in the specimens showing structure the leaves have not been found 

 in connexion with the stem, yet their position is evident, from that 

 of the leaf-trace vascular bundles, the course of which can be clearly 

 traced. Their distribution follows the same general lines as in 

 JEquisetum, but shows some additional complications. 



In the internode, a single circle of collateral vascular bundles 

 surrounds a relatively large pith, which is solid in some of the smallest 

 twigs, but became fistular in all the larger stems. 



In comparing the vegetative organs with those of Equisetum, it is 

 evident that only the primary structure of Calamites can be taken 

 into consideration. 



YOL. LV. K 



