PROOFS, ILLUSTRATIONS, AUTHORITIES, ETC. XXV 



to consider as the most simple and least perfect, owe this special 

 nature to a first phase of development in the organization of the 

 vegetable kingdom, which had not yet attained the perfection which 

 it afterwards reached ; or is it owing to the influence of the physical 

 conditions under which the surface of the earth was then placed ? 

 These are questions we cannot answer. 



" I shall merely remind the reader that I have already pointed out 

 the analogy which this predominance of Acrogenous Cryptogams 

 establishes between the vegetation of the first period, and that of the 

 small islands of the equatorial and southern temperate zone, in which 

 the maritime climate reaches its highest degree. However, this 

 predominance is not such as to entail, as during the carboniferous 

 period, the exclusion of phanerogamous vegetables, and this com- 

 plete exclusion would seem more favourable to the idea of a gradual 

 development of the vegetable kingdom." 



" All that we at present know of the vegetation of the globe at 

 the period of the earliest known fossiliferous deposits is that it was of 

 that more simple or less developed kind which characterises the 

 tribes growing in the sea. 



" The most ancient terrestrial Flora with which palaeontologists 

 have any real acquaintance is that of the carboniferous period ; and 

 this contains coniferae, which, although by no means the lowest of 

 the phsenogamous class, are still far from being ranked among the 

 highest. AVhether some of the fossil coal plants are referable to the 



family of true Palms, is a point as yet not clearly determined 



Of the 500 species of coal plants to which the critical and scrupulous 

 investigations of Adolphe Brongniart have restricted the fossil evi- 

 dences, one half at least are ferns, and the greater part of the re- 

 mainder are gymnosperms .... none of the exogens of Lindle} 7 or 

 dicot}'ledonous angiosperms of Brongniart, which comprise four- 

 fifths of the living Flora of the globe, have yet been discovered in 

 the coal measures. It must be remembered, too, when the value of 

 negative evidence is called in question, that the whole of Europe 

 does not produce more than fifty species of ferns only one-fifth of 

 the number that have left their remains in our coal strata; and ac- 

 cordingly M. Brongniart lias called the Flora of the carboniferous 

 and Permian strata, the ' age of Acrogens.' 



" In the strata from the triassic to the Purbeck, inclusive, plants 

 of the family of Zamia and Cycas, together with coniferse, predomi- 

 nated in Europe far more than anywhere now on the globe in 

 corresponding latitudes, and this fauna Brongniart calls the ' age of 

 Gymosperms.' 



" Now we presume it will be admitted that Cryptogamia, Phgeno- 

 gamia, Gymnosperms, and Dicotyledonous Angiosperms constitute a 

 succession and a progressive one" [Professor Oiven?^ Quarterly 

 Revieio, Sept. 1851. 



Dr. Carpenter, treating of the doctrine of the passage from the 

 more general to the more special, says of the geological history of 



