280 COSMOS. 



and more elevated portions of the old red sandstone, was main 

 tained through all the subsequent epochs to the most recent 

 chalk formations ; amid the peculiar characteristics exhibited 

 in the vegetable forms contained in the coal measures, there 

 is, however, a strikingly-marked prevalence of the same fami- 

 lies, if not of the same species, =^ in all parts of the earth as it 

 then existed, as in Nsw Holland, Canada, Greenland, and 

 Melville Island. 



The vegetation of the primitive period exhibits forms which, 

 from their simultaneous affinity with several families of the 

 present world, testify that many intermediate links must have 

 become extinct in the scale of organic development. Thus, 

 for example, to mention only two instances, we would notice 

 the Lepidodendra, which, according to Lindley, occupy a place 

 between the Coniferee and the Lycopodiaceae,t and the Arau- 

 carise and pines, which exhibit some peculiarities in the union 

 of their vascular bundles. Even if we limit our consideration 

 to the present world alone, we must regard as highly import- 

 ant the discovery of Cycadea3 and Coniferaj side by side with 

 Sagenarise and Lepidodendra in the ancient coal measures. 

 The Coniferai are not only allied to Cupuliferce and Betulina3, 

 with which we find them associated in lignite formations, but 

 also with Lycopodiacea). The family of the sago-like Cyca- 

 dese approaches most nearly to palms in its external appear- 

 ance, while these plants are specially allied to Conifera> in re- 

 spect to the structure of their blossoms and seed 4 Where 

 many beds of coal are superposed over one another, the fami- 

 lies and species are not always blended, being most frequently 

 grouped together m separate genera ; Lycopodiacece and cer- 

 tain ferns being alone found in one bed, and Stigm arise and 

 Sigillarise in another. In order to give some idea of the lux- 

 uriance of the vegetation of the primitive v/orld, and of the 

 immense masses of vegetable matter Avhich was doubtlessly 

 accumulated in currents and converted in a moist condition 

 into coal,§ I would instance the Saarbriicker coal measures, 



* Adolphe Brongniart, Prodrome d\ine Hist, des Vigitaux FossileS; p. 

 179 ; Bucldand, Geology, p. 479; Eudlicher aud Unger, Grundzuge der 

 Botanik, 1843, s. 455. 



t " By means of Lepidodendron, a better passage is established from 

 flowci'ing to flowerless plants than by either Equisetum or Cycas, or 

 aiiY other known genus." — Lindley aud Hutton, Fossil Flora, vol. ii., 

 p. "53. 



t Kuntli, Anordnnng der Pjlanzenfamilien, in his Handh. der Botanik^ 

 8. 307 und 314. 



§ That coal lias not been formed from vosrelable fibers cliarred by 



