Some Remarks on the Anatomy of the Osmundaceae, 
BY 
D. T. GWYNNE-VAUGHAN, M.A., F.R.S.E., F.L.S. 
Professor of Botany in Queen's University , Belfast. 
With Plate XLIV and five Diagrams in the Text. 
HE investigations that have given rise to this account were begun 
-1 with the intent of finding out whether any of the primitive features 
exhibited by certain fossil Fern stems assigned to the Osmundaceae by 
Dr. Kidston and myself 1 were still retained in the young plants of the 
existing representatives of the order. Before they were completed, however, 
a full description of the anatomy of Osmunda cinnamomea was published 
by Professor J. H. Faull, 2 with whose observations my own agree very 
closely. A short account of the facts in Osmunda regalis may still be 
justified, because I place an entirely different interpretation upon them to 
that advanced by Professor Faull, and in any case confirmation in a different 
species is not without value. 
My observations were chiefly made upon serial microtome sections of 
sporelings of Osmunda regalis. A few sporelings of 0 . palustris and of 
a Todea were also examined, but without materially affecting the results. 
The stem of the young sporeling curves round at once from its point 
of attachment to the prothallus into an obliquely erect position. The first 
leaf constantly departs from a point directly opposite to the foot, and the 
protoxylems of the diarch xylem of the first root lie in the plane running 
through the foot and the first leaf. The second leaf arises opposite to the 
first, but the subsequent leaves are arranged radially. In Osmunda cinna¬ 
momea , Faull found that the two-ranked arrangement is continued until the 
fifth or eighth leaf. He also discovered a cortical mycorhiza in the first 
roots of this plant which is not present in those of O. regalis. 
Attention was especially directed to the effect of the departure of the 
1 Kidston and GWynne-Vaughan : On the Fossil Osmundaceae. Part I, Trans. Roy. Soc. Edin., 
vol. xlv, 1907, p. 759. Parts II and III, vol. xlvi, 1908-9, p. 213, and p. 651. Part IV, vol. xlvii, 
1910, p.455. 
2 Faull: The Stele of Osmunda cinnamomea. Trans. Canadian Institute, vol. viii, 1909, 
P- 5 i 5 . 
[Annals of Botany, Vol. XXV. No. XCIX. July, 1911.] 
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