224 



GEOLOGY. 



Tig. 127. 



Fig. 128. 



and. Many of the ferns were trees resembling the tree- 

 ferns now found in some tropical countries, growing to 

 the height sometimes of even 40 and 50 feet. It is stated 

 by Hitchcock that over 250 species of ferns have been 

 found in the coal strata of Europe, and yet the native 

 species in Europe at the present time do not exceed 50. 

 As ferns are now far more abundant in tropical than in 

 temperate regions, the life-record of the coal-measures 

 seems to show that the climate in Europe and this coun- 

 try during the coal period was tropical. 



324. Conifers. The Conifers, or cone-bearing plants, 

 were very abundant. These are Gymnogens, or dicotyl- 

 edonous plants (Fig. 87), related to the pines and yews. 

 Most of the other plants of this age were Acrogens 

 (Fig. 86), the Ferns, the Equisetacea3, or cat-tail family, 

 and the Lycopodiacese, or club-mosses. The Amphigens 

 (Fig. 85) were represented in sea-weeds and a few mush- 

 rooms. It is doubtful whether there were any Endo- 

 gens (Fig. 88), and there were none of the Exogens 

 (Fig. 91), the chief forest-trees and shrubs of the present 

 day. 



325. General View of Carboniferous Vegetation. In 

 Fig. 129 you have grouped together many of the differ- 

 ent kinds of plants of the Carboniferous age. On the 

 right, in the foreground, is the Sigillaria, with Stigmaria 



