Is the Eusporangiate or the Leptospor- 
angiate the more primitive type in the 
Ferns 1 ? 
BY 
F. O. BOWER, 
Regius Professor of Botany in the University of Glasgow . 
With Plate VII. 
I N my paper on 4 The comparative examination of the 
Meristems of Ferns as a phylogenetic study,’ published in 
the Annals of Botany, vol. Ill, p. 305, &c., a very consider- 
able number of facts were passed in review, relating to the 
embryonic tissues of root, stem, leaf, wing, and sporangium ; 
the observations were made upon representatives of various 
divisions of the Filicineous series, viz. the Hymenophyllaceae, 
Polypodiaceae, Cyatheaceae (in part), Schizaeaceae, Osmunda- 
ceae, and Marattiaceae. The main result was to show that 
there is a singular parallelism in character of all the meristems 
in these several divisions ; it was demonstrated that, in the 
divisions first named, the meristems of each of the constituent 
parts of the plant are relatively simple in construction, and 
exhibit a definite regularity of segmentation, one initial cell 
(or in the wings a row of initial cells) of definite form being 
present in each. Passing onwards through the series, this 
simplicity and regularity is departed from ; the structure be- 
1 This question was discussed by the author at the Royal Horticultural Society’s 
Conference on Ferns, in July, 1890, and a statement of his views then put forward 
is printed in the Journal of the Society, N. S, vol. XII. pp. 496-505. 
[Annals of Botany, Vol. V. No. XVIII. April, 1891.] 
I 
