THE EVOLUTION OF PLANTS 613 



In the background, at the left, are the unbranched 

 Sigillarias, and the branched Lepidodendrons. The Cor- 

 daitales, which formed the Devonian forests, were not yet 

 extinct, but none is shown in the figure. Other forms, 

 ancestors of our modern conifers and angiosperms, must 

 be imagined as hidden in the recesses of the forest. 



526. Significance of the Fossil Record. — Before the 

 brilliant discoveries in fossil botany, just outlined, were 

 made, there had been (as stated in Chapter XXXVI) a 

 general tendency among botanists to consider the compar- 

 atively simple moss-plants as an older type than the fern, 

 and that either they or their close relatives were the ances- 

 tors of Pteridophytes. As outlined in the same chapter, 

 the sporogonium of the moss was regarded as representing 

 the form from which, by elaboration of vegetative tissues 

 and organs, the sporophyte of the fern was derived. This 

 view was clearly expressed in 1884 by the noted botanist 

 Nageli, who considered that the sporophyte of Pterido- 

 phytes was derived from a moss-like sporogonium by the 

 development of leafy branches. 



Fig. 432. — Restoration of a scene along a sluggish creek in Texas and 

 New Mexico during the late Carboniferous (Upper Pennsylvania) and 

 early Permian times. The lowlands of this period doubtless swarmed 

 with reptiles such as shown in the picture, and with other animals, now 

 extinct. Some specimens of the giant " dragon-flies " had a spread of 

 wings of two feet. The fern-like trees and the bushy plants in the fore- 

 ground are Cycadofilicales. To the right of the water are wide stretches 

 of the huge scouring rush (Calamiles); on the left bank of the stream are 

 the unbranched Sigillarias (still as prominent as earlier in the coal 

 period), and on higher ground to the left the branched Lepidodendrons. 

 One must view this scene as one of many such landscapes, with ever- 

 varying detail, along streams and inlets. Cordaites, which in later 

 Devonian time made the first great forests of which there is record, is 

 still present, though not shown. So, too, there are hidden in the recesses 

 of the forest the forerunners of the modern coniferous types, as well as 

 other forms destined to give rise to the angiosperms. (Landscape from 

 Williston, adapted from Neumayr. Legend modified from Shimer.) 



