10 FOSSIL PLANTS. 



leaves, as in C. Cistii, or verticillate branchlets with pinnate or verticillate leaflets, as in 

 C. Suckovii and C. nodosus. The Calamites do not seem to have contributed much to 

 the growth of coal, though their remains are not infrequent in it. The soils in which 

 they most frequently grew were apparently too wet and liable to inundation and silting 

 up to be favorable to coal-accumulation. I have elsewhere shown (' Quart. Journ. Geol. 

 Soc./ vol. X, p. 34) that some of the species of Calamites gave off numerous adventitious 

 roots from the lower parts of their stems, and also multiplied by budding at their bases" 

 (p. 135). 



Again, at pp. 140, 141, in treating of discigerous wood-cells. Dr. Dawson says : 

 " These are the true bordered pores characteristic of Sigillaria, Calamodendron, and 

 Dadoxylon. In the two former genera the discs or pores are large and irregularly 

 arranged, either in one row or several rows. In the latter case they are sometimes regu- 

 larly alternate and contiguous. In the genus Dadoxylon they are of smaller size, and 

 always regularly contiguous in two or more rows, so as to present a hexagonal areolation. 

 Discigerous structures of Sigillaria and Calamodendron are very abundant in the coal, 

 and numerous examples were figured in my former paper. I have indicated by the 

 name reticulated tissue certain cells or vessels which may either be reticulated scalariform 

 vessels, or an imperfect form of discigerous tissue. I believe them to belong to Stigmaria 

 or Calamodendron. (Figs. 57 and 68, PI. XII.)" 



§ 11. Professor Dr. C. von Ettingshausen^ has lately described and figured some 

 interesting specimens of Calamites showing their branches and leaves, but not affording 

 much evidence of their internal structure. 



§ 12. When the present memoir was nearly all written, Mr. Carruthers, after seeing 

 some of my specimens, gave a restored figure of Calamites in a paper published in 

 December, 1866,^ in which he concludes, "It is not easy to find anything analogous to 

 Calamites among recent plants ; nevertheless its structure does not differ so essentially 

 from the vascular cryptogams as to cause any uncertainty as to its position. The 

 histological character of its wood, the absence of medullary rays, and the nature of its 

 fruit, clearly establish that it was a true cryptogam ; and while it differed in the arrange- 

 ment of the parts of its stem, in its foliar appendages, and in its organs of fructification, 

 from Lepidodendron, yet it is evident that these were both near allies, and both 

 more highly organized than any of their living representatives." 



' ' Die fossile Flora des Nahrisch-Schlesischen Dachschiefers ; Denkscriften der Kaiserlichen Akademie 

 der Wissenscbaften,' Wien, 1866. 



2 "On the Structure and Affinities of Lepidodendron and Calamites," by W. Carruthers, F.L.S., 

 Botanical Department, British Museum ; ' Seeman's Botanical Magazine' for December, 1866. In the 

 ' Popular Science Review' for July, 1867, p. 295, &c., Mr, Carruthers has further described and figured 

 the Calamite and its fruit. 



