PALAEONTOLOGY. 283" 



of the same families, if not of the same species* in all parts of 

 the earth as it then existed, as in New 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 conifers and the lycopodiaceae,f and the arauca- 

 ^ise and pines, which exhibit some pecu liaritiesin the union of 

 their vascular bundles. Even if we limit our consideration to 

 the present world alone, we must regard as highly important, 

 the discovery of cycadea3 and coniferae side by side with 

 sagenarisc and lepidodendra in the ancient coal measures. 

 The coniferae are not only allied to cupuliferaB and betulinae 

 with which we find them associated in lignite formations, 

 but also with lycopodiacetc. The family of the sago-like cyca- 

 deso approaches most nearly to palms in its external appear- 

 ance, whilst these plants are specially allied to coniferse in. 

 respect to the structure of their blossoms and seed.J Where 

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

 lies and species are not always blended, being most frequently 

 grouped together in separate genera ; lycopodiaceaB and cer- 

 tain ferns being alone found in one bed, and stigmariai and 

 sigillariae in another. In order to give some idea of the 

 luxuriance of the vegetation of the primitive world, and of 

 the immense masses of vegetable matter which was doubtless- 

 lessly accumulated in currents and converted in a moist con- 

 dition into coal, I would instance the Saexbriicker coal 



* Adolphe Brongniart, Prodrome dune Hist, des Vegetaux fossiles, 

 p. 179 ; Buckland, Geology, p. 479 ; Endlicher and linger, Qrundzuge 

 der Botanik, 1843, s. 455. 



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

 flowering to flowerless plants, than by either Equisetum or Cycas, or any 

 other known genus." Lindley and Hutton, Fossil Flora, vol. ii. p. 53. 



J Kunth, Anordnung der Pflanzenfamilien in his Handb. der 

 Botanik, s. 307 und 314. 



That coal has not been formed from vegetable fibres charred by 

 fire, but that it has more probably been produced in the moist way by 

 the action of sulphuric acid, is strikingly demonstrated by the excellent 

 observation made by Goppert (Karsten, Archiv fur Mineralogie., 

 bd. xviii. 8. 530), on the conversion of a fragment of amber-tree into 



