758 Bancroft.—On the Xylem Elements of the Pteridophyta . 
References. 
1. De Bary : Vergleichende Anatomie der Vegetationsorgane. Hofmeister, Handbuch der 
physiol. Bot., Bd. iii, 1877. 
2. G wynne-Vaughan, D. T. : On the Real Nature of the Tracheae in the Ferns. Ann. of Bot., 
vol. xxii, 1908, p. 517. 
3. Halft, Fr. : Die Schliesshaut der Hoftiipfel im Xylem dev Gefasskryptogamen, 1910. 
Dissertation. 
4. Kershaw, E. M.: A Fossil Solenostelic Fern. Ann. of Bot., vol. xxiv, 1910, p. 683. 
5. Kidston, R., and Gwynne-Vaughan, D. T. : On the Fossil Osmundaceae, Pt. I. Trans. Roy. 
Soc. Edin., vol. xlv, Pt. Ill, 1907, p. 759. 
6. - — -: lb., vol. xlvi, Pt. II, 1908. 
7. Mangin, L. : Sur la presence des composes pectiques dans les v^g^taux. Bull, de la Soc. bot. de 
France, t. cix, 1889, p. 579. 
g, -- ; Sur les reactifs colorants des substances fondamentales de la membrane. Ib., 
t. cxi, 1890, p. 120. 
9. -: Sur la substance intercellulaire. Ib., t. cx, p. 295. 
10. Russow : Vergleichende Untersuchungen. Mem. de l’Acad. Imp. des Sci. de Saint-P^tersbourg, 
t. xix, 1872. 
11. San 10 : Anatomie der gemeinen Kiefer. Pringsh. Jahrb., Bd. ix, 1873. 
12. Seward, A. C. : Fossil Plants. Vol. i, 1898, pp. 215-16. 
13. ~—--- : Ib., vol. ii, 1910, pp. 470-2. 
14. Sinnott, E. W.: Foliar Gaps in the Osmundaceae. Ann. of Bot., vol. xxiv, 1910, p. 107. 
15 . Stevens, Wm. C.: Plant Anatomy. Second ed., 1910, p. 313. 
16. Strasburger, E.: Uber den Bau und die Vorrichtungen der Leitungsbahnen in den Pflanzen. 
1891. 
17. -——-: Text-book of Botany. Third English ed., 1908, p. 99. 
(Further references may be found in the works quoted.) 
EXPLANATION OF PLATE LVI. 
Illustrating Miss Bancroft’s paper on the Xylem Elements of the Pteridophyta. 
(The figures are semi-diagrammatic, the magnification being 1,500 diams. in each case). 
Fig. 1. Matonia pectinata . Transverse section of xylem elements of rhizome, showing the 
middle lamella traversing wide spaces between them. 
Fig. 2. Matonia pectinata. Longitudinal section, showing narrow connexions of the thickening 
bars. 
Fig. 3. Marattia fraxinea. Transverse section of xylem of petiole. The thickening bars are 
closely connected ; no spaces show between them. 
Fig. 4. Marattia fraxinea. Longitudinal section through a series of lignified bars. Note the 
wide connexions between successive pairs. A pointed end of an element is also shown ( a ). 
Fig. 5. Angiopteris evecta. Longitudinal sections. Cf. Fig. 4, showing the same type. 
Fig. 6. Gleichenia dicarpa. Transverse section of xylem of rhizome, showing the torn lignified 
bars and the projecting lamella. 
Fig. 7. Sclaginella Wildenovii. Transverse section of xylem of stem. The spaces between 
the bars are relatively narrow. 
