262 
Browne . — The Anatomy of the 
11. The sporangiferous annulus is regarded as derivative in the genus 
£ guise turn, and the reasons for this view are briefly examined. 
12. In E. giganteum the uppermost vegetative node of the fertile 
branch shows no persistent diaphragm. 
In conclusion I wish to express to Professor F. W. Oliver, F.R.S., in 
whose laboratory these investigations were carried out, my thanks for his 
encouragement and help, as well as for the material of E. hyemale which he 
placed at my disposal. My thanks are also due to Professor R. C. Maclean, 
D.Sc., for cones and for a dried specimen of E> giganteum collected by him 
in Chile, and to the authorities at Kew who assisted in the determination of 
the material of this species* 
Literature quoted. 
Bower, F. O. : Studies in the Morphology of Spore-producing Members. No. V. Comparisons 
and Conclusions. Philosophical Transactions of the Royal Society, Series B., vol. cxcvi, 
1903, pp. 191-257. 
Browne, I. : (1) Contributions to our Knowledge of the Anatomy of the Cone and Fertile Stem of 
Equisetum. Annals of Botany, vol. xxvi, No. ciii, 1912, pp. 663-703. 
: (2) A Second Contribution to our Knowledge of the Anatomy of the Cone and Fertile 
Stem of Equisetum. Annals of Botany, yol. xxix, No. cxiv, 1915, pp. 231-64. 
Duval-Jouve, J. : Histoire naturelle des Equisetum de France. Paris, 1864. 
Milde, J. : Monographia Equiseterum. Nova Acta Academiae Caesareae Leopold : Carol. 
Germanicae Naturae Curiosorum, vol. xxiv, Part II, Dresden, 1867. 
Vaucher, J. P. E. : Monographic des Preles. M&noires de la Society de Physique et d’Histoire 
naturelle de Geneve, vol. i, Part II, 1812, pp. 329-91. 
EXPLANATION OF PLATES VIII AND IX. 
Illustrating Lady Isabel Browne’s paper on Equisetum. 
PLATE VIII. 
Fig. 1. Tangential longitudinal section through the annulus and lower part of the cone 
of E giganteum. At the base of the section is the annulus, near the edge of which may be seen 
three annular bundles, x 20. 
Fig. 2. Radial longitudinal section of the annulus and the lower part of the cone of E. 
giganteum , showing two of the annular bundles and sporangia. The sporangium on the reader’s 
right is partially covered by a sporangiophore which was accidentally bent down during the pre- 
paration of the section. The section passes through the point of attachment of the bundle running 
to the insertion of this sporangium, but just misses that of the bundle corresponding to the sporan- 
gium on the reader’s left, x 25. 
Figs. 3, 4, 7, and 9. Transverse sections of axial bundles of E. giganteum below the insertion 
of the annulus. Note the persistent tracheides adherent to the inner side of the carinal canals. The 
tendency of the carinal canals below the cone to be widest transversely is still to be seen at this 
level, x 20Q. 
