Ch. XXIV.] GRADE OF THE CARBONIFEROUS FLORA, 



371 



growth of some plants, and as tliey appear in many acrogens, tliey do 

 not seem to mark a high development. In fine, there is much ambi- 

 guity in deciding what should or should not be called high or low in 

 vegetable structure, and physiologists entertain very diflferent abstract 

 ideas as to the perfection of certain organs and their relative func- 

 tional importance, even where the function is clearly ascertained. It is 

 enough for the geologist to know, that fossil Coniferse abound in the 

 oldest rocks yielding a considerable number of vegetable remains, and 

 that plants of this order lay claim, if not to the highest, at least to so 

 high a place in the scale of vegetable life, as to preclude us from char- 

 acterizing the carboniferous flora as consisting of imperfectly developed 

 plants. 



Although our data are confessedly too defective. to entitle us to gen- 

 eralize respecting the entire vegetable creation of this era, yet we may 

 affirm that so far as it is known it differed widely from any flora now 

 existing. The comparative rarity of Monocotyledons and of Dicotyle- 

 donous Angiosperms seems clear, and the abundance of Ferns and Lyco- 

 pods m.ay justify Adolphe Brongniart in calling the primary periods the 

 age of Acrogens.* (" Le regne des Acrogens.") As to the Sigillarise 

 and Calamites, they seem to have been distinct from all tribes of now- 

 existing plants. That the abundance of ferns implies a moist atmo- 

 s|)here, 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 cold and 

 moist regions. In New Zealand the Coniferse attain their maximum in 

 numbers, constituting gLd part of all the flowering plants ; whereas 

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

 y-gL^th 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. 



Angiosperms. — Some of the grass-like leaves 

 termed Foacites, having fine longitudinal striae, are 

 conjectured to belong to Monocotyledons ; but the 

 determination is doubtful, as some of them may be 

 the leaves of Lepidodmdra^ 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. 488). But Dr. Hooker suggests that these 

 may be rather tufts of scarcely opened buds with the 

 young leaves just bursting. He suggests that they 

 may be coniferous, although he cannot connect them 



With any known fossil conifer. Colliery, Newcastle. 



For terminology of classification of plants, see above, note, p. 265. 



