part 2] ANNIVERSARY ADDRESS OF THE PRESIDENT. XC1X 



bearing base to their steins. With these were plants of which we 

 have less knowledge, foreshadowing in the plan of their branching 

 the ferns of a later age, but for the most part characterized by the 

 absence of foliar appendages provided with a flat lamina. Stems 

 of ferns with the vascular tissue preserved are known from the 

 Upper Devonian of Canada and Australia ; branched axes identical, 

 except in the absence of leaflets, with the fronds of typical ferns 

 are recorded from Middle Devonian horizons ; but from the older 

 Devonian localities very few examples have been discovered of 

 organs with a flat lamina. Specimens described by Nathorst from 

 Middle Devonian rocks in Western Norway as Psygmophyllum 

 Jcolderupi show wedge-shaped laminae, attached to slender branches 

 which resemble the leaflets of Arcliceopteris : it is not clear 

 whether they are simple leaves, or leaflets of a compound frond. 

 A specimen in the British Museum (Natural History) from the 

 Middle Devonian of Caithness bears a close resemblance to an 

 Upper Devonian species named by Dawson Platyphyllum browni- 

 anum, and in shape agrees with the genus Psygmophyllum as 

 represented in the Upper Devonian flora of Spitsbergen and in the 

 Carboniferous floras of different regions. Dr. David White con- 

 siders that Dawson's Platyphyllum is probably algal, and not a 

 true leaf. The Caithness fossil, although it may be a leaf, shares 

 with the Canadian specimens the possession of delicate vein-like 

 markings which do not suggest true vascular strands. If we are 

 correct in assuming that the majority of the older Devonian plants 

 so far described grew on low-lying or swampy ground, the possi- 

 bility must be admitted that in situations less favourably placed 

 for the preservation of samples of the vegetation, and under other 

 physical and climatic conditions, there may have lived representa- 

 tives of a higher type of organization — plants with more woody 

 and less succulent stems, comparable with the Gymnosperms of 

 Upper Devonian floras. So far as I am aware, there is as yet no 

 thoroughly satisfactory evidence of the existence prior to Upper 

 Devonian times of any undoubted Gymnosperm. Dr. D. H. Scott 

 has emphasized the importance of bearing in mind the fossil stem 

 called by W. \i. McNab Paloeopitys milleri, from the Middle 

 Devonian of Cromarty, and often spoken of as a Conifer. A 

 piece of the specimen originally described by Hugh Miller is being 

 investigated by Dr. R. Kidston & Prof. W. H. Lang; and mean- 

 while I can only state that the former tells me that the structure 

 is not that of a typical Gymnosperm. J. S. NeAvberry described 



9* . 



