the Leaf of Welwitschia mirabilis . 357 
13. Rothert, W. : Ueber die anatomischen Differenzen der Gattungen Dracaena und Cordyline. 
Bull. Dep. Agr. Ind. Norland., No. 24, 1909. 
14. Scheit, M. : Die Tracheidensaume der Blattbiindel der Coniferen, etc. Jenaische Zeitsch. f. 
Naturwissenschaft, xvi, 1883. 
15. Solereder, H. : Systematic Anatomy of the Dicotyledons. Engl. Trans., 1908. 
16 . Solms-Laubach, Graf zu : Ueber einige geformte Vorkommnisse oxalsauren Kalkes in 
lebenden Zellmembranen. Bot. Zeitg., 1871. 
17 . Strasburger, E. : Die Coniferen und die Gnetaceen. 1872. 
18. : Leitungsbahnen. 1891. 
19. Sykes, M. G. : The Anatomy and Morphology of the Leaves and Inflorescences of Welwitschia 
mirabilis. Phil. Trans., cci, ser. B, 1910. 
20. : The Anatomy of Welwitschia mirabilis , Hook, f., in the Seedling and Adult 
States. Trans. Linn. Soc. London, Bot., ser. 2, vii, 1910. 
21 . Takeda, H. : A Theory of ‘ Transfusion-tissue ’. Ann. Bot. xxvii, 1913, p. 359. 
22. : Development of the Stoma in Gnetum Gnemon. Ibid., p. 365. 
23. Zimmermann, A. : Ueber das Transfusionsgewebe. Flora, lxiii, 1880. 
EXPLANATION of figures in PLATE XXIX. 
Illustrating Mr. Takeda’s paper on the Leaf Anatomy of Welwitschia mirabilis. 
All figures were drawn with the aid of Abbe’s drawing apparatus. 
Fig. 1. Cotyledon showing the nervation, x 4|. C.b. = central bundle. L.b. = lateral bundle. 
M.b. — marginal bundle. Conn. = connate portion at the base. 
Fig. 2. Stoma in surface view. From a horizontal section cut at the level of the outer ridge of 
the guard cell, x 450. 
Fig. 3. Epidermis of the under surface of the leaf. Stoma are cut at the median portion, 
x 450. C. = cuticle. C.l. = cuticularized layer. M.l. = middle lamella. C.w. = cellulose wall. 
Scl. f. = sclerenchymatous fibre. Spic. = spicular cell. Pal. — palisade parenchyma. 
Fig. 4. Surface view of the epidermis of the under side of the leaf, x 285. 
Fig. 5. A portion of a transverse section of the cotyledon (under surface), x 450. 
Fig. 6. Longitudinal section of a stoma of the upper surface of the leaf, x 450. Lettering is 
same as in Fig. 3. 
Fig. 7. Transverse section of a vascular bundle of the leaf, x 285. Pr. x. = protoxylem. 
W. t. = water-storing tracheides. X.p. = xylem parenchyma. 
Fig. 8. Water-storing tracheides of the cotyledon. From a longitudinal section ; compare with 
Fig. 9. x 500. Chi. = chlorophyll-containing cell. 
Fig. 9. Transverse section of the main bundle of the cotyledon, x 450. Pr.x. = protoxylem. 
Pr.ph. — protophloem. Scl. f. — sclerenchymatous fibre. W. t. = water-storing tracheide. 
Fig. 10. Portion of the xylem-parenchyma. From a longitudinal section of the leaf ; compare 
with Fig. 7, X.p. x 285. 
Fig. 11. Portion of sieve-tubes and phloem-parenchyma. From a horizontal section of the 
leaf, x 500. 
Fig. 12. A portion of a longitudinal section of vessels. X 450. 
