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large spreading fronds and a short root-covered stem, 

 which occurs in Australia and Cape Colony, all the 

 species of this genus are filmy ferns with semi- 

 transparent fronds adapted to a moisture-laden 

 atmosphere. - O410 filmy opooion of Todea is repre- 

 sented in tho Brititf l i lima b) Toden mdwans in 

 t he Killatne) di. ' ^tiict uf Ireland ; but the maximum 

 development of the genus is in New Zealand. 



Todea harhara affords an instance of discontinuous 

 distribution ; it was no doubt once widely spread in 

 circumpolar regions and noAV survives only in South 

 Africa and in Australia. 



There are satisfactory reasons for regarding the 

 Bracken Fern, with its world-wide range in present- 

 day floras, as a comparatively modern species now in 

 full vigour. Its anatomical and other features are 

 consistent with the view that it is a late product of 

 evolution, and as yet no indication has been given by 

 the records of the rocks of an ancient lineage. The 

 Osmunda family, on the other hand, is undoubtedly 

 an extremely old branch of the fern group. A com- 

 parison of the Royal Fern with the Bracken shows 

 that their stems are constructed on very different 

 plans, and we have good reasons for speaking of the 

 structural peculiarities of the former as those of 

 a more primitive type. Moreover, the discontinuous 

 geographical range of some members of the Osmunda 

 family is in itself an indication of antiquity. There 



