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 comparison 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 is another point which may have a bearing in this question of antiquity, namely the fact that the spores of Osmunda are green and do not possess the powers of indurance inherent in the spores of the majority of ferns which are not green. It has recently been contended by Professor Campbell of Stanford University that the delicate green spores of the Liverworts, plants closely allied to the Mosses, constitute an argument in favour of the antiquity of these plants(46). Certain Liverworts are cosmopolitan in their range, _e.g._ the genera Riccia and Marchantia. If certain genera are widely distributed, notwithstanding the fact that their reproductive cells, by which dispersal is effected, are ill-adapted to withstand unfavourable conditions or to endure prolonged desiccation, it would seem reasonable to conclude that their emigration has been accomplished slowly and with difficulty. Ferns such as Osmunda, with green and short-lived spores, would thus be handicapped in competition with other genera provided with more efficient means of dispersal and better equipped for the vicissitudes of travel. The inferences as to antiquity deduced from a study of the existing species of Osmunda and Todea receive striking confirmation from the testimony of fossils. Some of the oldest known Palaeozoic ferns, though differing too widely from the existing Osmundas and Todeas to be included in the same family, afford distinct glimmerings of Osmundaceous characters, which at a later period became individualised in the direct ancestors of the modern forms. Our knowledge of the past history of the Osmunda family has recently been considerably extended and placed on a firmer basis by the researches of Dr Kidston and Professor Gwynne-Vaughan. These authors have recognised in some exceptionally well-preserved fern-stems from Permian rocks in Russia, anatomical features which point unmistakably to close relationship with the recent members of the family(47)(48).