Early History of Ferns 213 



nearer to the Ferns than to any other group, it must have differed 

 widely from the Ferns as we now know them, or perhaps even from 

 any which the fossil record has yet revealed to us. 



iii. TJie Origin of the Higher Cryptogamia. 



The Sub-kingdom of the higher Spore-plants, the Cryptogamia 

 possessing a vascular system, was more prominent in early geological 

 periods than at present. It is true that the dominance of the Pteri- 

 dophyta in Palaeozoic times has been much exaggerated owing to 

 the assumption that everything which looked like a Fern really was 

 a Fern. But, allowing for the fact, now established, that most of the 

 Palaeozoic fern-like plants were already Spermophyta, there remains 

 a vast mass of Cryptogamic forms of that period, and the familiar 

 statement that they formed the main constituent of the Coal-forests 

 still holds good. The three classes, Ferns (Filicales), Horsetails 

 (Equisetales) and Club-mosses (Lycopodiales), under which we now 

 group the Vascular Cryptogams, all extend back in geological history 

 as far as we have any record of the flora of the land ; in the Palaeo- 

 zoic, however, a fourth class, the Sphenophyllales, was present. 



As regards the early history of the Ferns, which are of special 

 interest from their relation to the Seed-plants, it is impossible to 

 speak quite positively, OAving to the difficulty of discriminating 

 between true fossil Ferns and the Pteridosperms Avhich so closely 

 simulated them. The difficulty especially affects the question of the 

 position of Marattiaceous Ferns in the Palaeozoic Floras. This 

 family, now so restricted, was until recently believed to have been 

 one of the most important groups of Palaeozoic plants, especially 

 during later Carboniferous and Permian times. Evidence both from 

 anatomy and from sporangial characters appeared to establish this 

 conclusion. Of late, however, doubts have arisen, owing to the 

 discovery that some supposed members of the IMarattiaceae bore 

 seeds, and that a form of fructification previously referred to that 

 family (Crossotheca) vras really the pollen-bearing apparatus of a 

 Pteridosperm (Lyginodendron). The question presents much diffi- 

 culty ; though it seems certain that our ideas of the extent of the 

 family in Palaeozoic times will have to be restricted, there is still a 

 decided balance of evidence in favour of the view that a considerable 

 body of Marattiaceous Ferns actually existed. The plants in (juestion 

 were of large size (often arborescent) and highly organised — they 

 represent, in fact, one of the highest developments of the Fern-stock, 

 rather than a primitive type of the class. 



There was, however, in the Palaeozoic period, a considerable 

 group of comparatively simple Ferns (for which Arber has proposed 



