A TYPE OF PALEOZOIC PLANTS. 399 



lately no evidence that Angiosperms were represented in 

 the vegetation of the Palaeozoic Era. Now, on the other 

 hand, the Angiosperms share with the Gymnosperms the 

 making of our forests, and with the exception of some 

 ferns, the Vascular Cryptogams are to a large extent small 

 herbaceous plants clinging as epiphytes to the stems of 

 phanerogams or tree-ferns, or growing in the shade of 

 larger trees. In the Palaeozoic forests Calamites, Lepido- 

 dendrons and other genera had to struggle upwards for the 

 light, and like the contemporary Gymnosperms or later 

 Dicotyledons, they possessed a power of growth which 

 placed them on a comparatively equal footing with the 

 more highly differentiated forest trees. The difference in 

 size and habit of life between the Palaeozoic and recent 

 lycopodinous and equisetinous plants, becomes in some 

 measure less striking when we bear in mind the fact that 

 the trees which predominated in the coal period vegetation 

 have since assumed a secondary importance, and have been 

 replaced by plants which are the outcome of other lines of 

 development, and have usurped the position formerly 

 occupied by types on a lower plane of organisation. 



In the recent paper by Williamson and Scott the 

 generic name Calamites is used in the wide sense, including 

 Calamodendron and Calamites of other authors. It may be 

 noted in passing that in Binney's important contribution to 

 our knowledge of calamitean structure in 1868, he adopts 

 the eenus Calamodendron, but admits that he is unable to 

 recognise any distinct indication of the existence of the two 

 forms of plants insisted on by Brongniart. 1 



It is but rarely that fragments of Calamites stems are 

 met with, in which the primary structure has not been 

 added to by the formation of secondary tissues. The 

 greater part of the pith of young twigs is usually hollow, 

 and the regular internal boundary of the parenchymatous 

 tissue suggests an originally fistular stem. The figures of 

 small branches given by Scott and Williamson, and in a 

 recent paper by Hick 2 "On the Primary Structure of the 



1 Binney, p. 16. 9 Hick (2). 



28 



