v] FERNS 75 



higher plants, namely the possession of seeds. The 

 ancestors of Pteridosperms are as yet unknown ; it 

 is, however, reasonable to assume that there existed 

 in some pre-Carboniferous epoch a group of simple 

 plants from which both Ferns and Pteridosperms 

 were derived. In the forests of the Coal age true 

 Ferns probably occupied a subordinate position in 

 relation to the Pteridosperms. 



The question of the relationship between different 

 families of recent ferns and the older known fossil 

 members of the group is beyond the scope of this 

 book. Evidence has been discovered in recent years 

 which warrants the statement that, although none of 

 those Carboniferous ferns were generically identical 

 with existing forms, they very clearly foreshadowed 

 some of those structural features which characterise 

 more than one family of present-day Ferns. The 

 records of the older Mesozoic formations afford 

 abundant evidence of the existence of certain types 

 of Ferns showing a very close resemblance to recent 

 species. 



An enquiry into the geographical distribution of 

 living Ferns reveals facts of special interest in 

 connexion with the relative antiquity of different 

 genera and families. The wide distribution of the 

 Bracken fern has already been referred to : it is 

 abundant in Tasmania ; its vigour in the island 

 is well illustrated by Mr Geoffrey Smith's statement 



