PLANTS OF THE COAL. 



371 



like stems, jointed and hollow, or else with large pith. The exterior 

 surface of the stem is finely striated or fluted, but the striae are not con- 

 tinuous nor marked with leaf- scars like the flirtings of the Sigillaria, but 



are interrupted at the joints 

 ia the manner shown in 

 Figs. 508 and 509. At the 

 joints are attached in whorls 

 the leaves, which are either 

 scale-like, or strap-like, or 

 thread-like. Sometimes at 

 the joints of the main stem 

 come out in whorls thread- 

 like, jointed branches, bear- 

 ing scale-like or thread-like 



Fig. 511. 



Fig. 512. 



Figs. 508-512.— Calamites and their Allies: 508. Lower End of Stem of Calamites from Nova 

 Scotia. 509. Lower End of Stem of Calamites cannseformis. 510. Sphenophylhim erosum 

 (after Dawson). 511. Asterophyllites foliosus, England (after Nicholson). 512. Annularia in- 

 flata (after Lesquereux). 



leaves. At the lower end of the stem, the joints grow rapidly smaller 

 and shorter, so that this end was conical. From these short, rapidly- 

 tapering joints came out the thread-like roots. The stem was termi- 

 nated above with a cone-like fruit (Fig. 513). 



What I have said thus far applies word for word to Equisetae ; but 

 the Equisetae of the present day are small, rush-like plants, never much 

 thicker than the finger, and seldom more than three or four feet high, 

 although in South America (Caracas) they grow thirty feet high, but 

 are very slender ; while Calamites were certainly two feet or more in 

 diameter, and thirty feet high. Fig. 514 is an attempt to reconstruct 

 the general appearance of a Calamite by Dawson. 



The internal structure of Calamites still further removes them from 

 Equisetae; for they seem to have had (some of them, at least) a thick, 



