Ch. XXiY.l 



ANGIOSPERMS— COAL, HOW FORMED. 



479 



Although our data are confessedly too defective to entitle us to 

 generalize respecting the entire vegetable creation of this era, yet we 

 may affirm that so for as it is known it differed widely from any flora 

 now existing. The comparative rarity of Monocotyledons and of Dico- 

 tyledonous Angiosperms seems clear, and the abundance of Ferns and 

 Lycopods may justify Adolphe Brongniart in calling the primary 

 periods the age of Acrogens * (" le regne des Acrogens "). As to the 

 Sigiilariaa and Calamites, they seem to have been distinct from all 

 tribes of now-existing plants. That the abundance of ferns implies a 

 moist atmosphere, is admitted by all botanists ; but no safe conclusion, 

 says Hooker, can be drawn from the Coniferse alone, as they are found 

 in hot and dry and in cold and dry climates, in hot and moist and in 

 c )ld and moist regions. In ISTew Zealand the Coniferse attain their 

 maximum in numbers, constituting -Jgd part of all the flowering plants ; 

 whereas in a wide district around the Cape of Good Hope they do not 

 form 1 * t h of the phenogamic flora. Besides the conifers, many 

 species of ferns flourish in New Zealand, some of them arborescent, 

 together with many lycopodiums ; so that a forest in that country may 

 make a nearer approach to the carboniferous vegetation than any other 

 now existing on the globe. 



mperms. — Some of the grass-like leaves termed Fig. 535. 

 PoaciteSj having fine longitudinal stria?, are conjec- 

 tured to belong to Monocotyledons ; but the deter- 

 mination is doubtful, as some of them may be the 

 leaves of Lepidodendra, others the stems of Ferns. 

 The curious plants called Antholithes by Lindley 

 have usually been considered to be flower-spikes, 

 having what seems a calyx and linear petals (see 

 fig. 535). Dr. Hooker suggested that they might 

 be tufts of young leaves like those of the larch, but, 

 after seeing the most perfect specimens, he no longer 

 thought them oniferous, but resembling rather the 

 spike of a highly organized plant in full flower, such A 

 as one of the Bromeliacese, to which Professor Lind- Colliery, Newcastle. 

 ley first compared them. In the absence, however, of 

 all structure, the affinities of these fossils are still considered very 

 uncertain. 



Coal, how formed. — Erect trees. — I shall now consider the manner 

 in which the above-mentioned plants are imbedded in the strata, and 

 how they may have contributed to produce coal. Professor Goppert, 

 after examining the fossil vegetables of the coal-fields of Germany, 

 has detected, in beds of pure coal, remains of plants of every family 

 hitherto known to occur fossil in the carboniferous rocks. Many 

 seams, he remarks, are rich in Sigillarice, Lepidodendra, and Stig- 

 marice, the latter in such abundance as to appear to form the bulk of 



* For terminology of classification of plants, see above, note 



