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~ . w a j eo ‘ ads : Gy SA hem ' , , a i MA 4 — EM os : K ae t ' Ci ay. " . Aiea: aed 9 as ee 2499° ANNALS OF BOTANY VOL. VII <S STANFORD Wn Se emmamnentiiititensaninetel OPT IE RARY, ” “” Nivea W.B.5571. Orford PRINTED AT THE CLARENDON PRESS BY HORACE HART, PRINTER TO THE UNIVERSITY ANNALS OF BOTANY EDITED BY ISAAC BAYLEY BALFOUR, M.A., M.D., F.R:S. QUEEN'S BOTANIST IN SCOTLAND, PROFESSOR OF BOTANY IN THE UNIVERSITY AND KEEPER OF THE ROYAL BOTANIC GARDEN, EDINBURGH SYDNEY HOWARD VINES, M.A., D.Sc., F.R.S. FELLOW OF MAGDALEN COLLEGE, AND SHERARDIAN PROFESSOR OF BOTANY IN THE UNIVERSITY OF OXFORD D. H. SCOTT, M.A., PH.D., F.LS. HONORARY KEEPER OF THE JODRELL LABORATORY, ROYAL GARDENS, KEW AND WILLIAM GILSON FARLOW, M.D. PROFESSOR OF CRYPTOGAMIC BOTANY IN HARVARD UNIVERSITY, CAMBRIDGE, MASS., U.S.A. ASSISTED BY OTHER BOTANISTS VOLUME VII With XXVII Plates, in part coloured, and 5 Woodcuts Bondon HENRY FROWDE, AMEN CORNER, E.C. OXFORD: CLARENDON PRESS DEPOSITORY, 116 HIGH STREET 1893 CONTENTS. No. XXV, March, 1893. PAGE SEWARD, A. C.—On the genus Myeloxylon (Brong.). (With Plates I NOTES. and II)... I Scott, D. H., and BREBNER, G. —On the Secondary Tissues i in certain Monocotyledons. (With Plates III, IV, and V) . . 21 CORMACK, B. G.— On a Cambial Development 4 in Hquisetaon. (With Plate VI). . . se 63 GREEN, J. R.—On Vegetable Ferments , . . . . . 83 OVERTON, E.—On the Reduction of the Chromosomes in the Nuclei of Plants . . . - 8 . . 139 Groom, P.—Botanical Notes : No. 4. On the Velamen of Orchids. . 143 No. 5. The Influence of External Conditions on the Form of Leaves . 152 Swan, A.—On the resisting Vitality of the Spores o of Bacillus. Megs terium to the condition of dryness . . 153 No. XXVI, June, 1893. CAMPBELL, D. H.—On the development of Azolla filiculoides tam.) (With Plates VII, VIII, and IX) . ‘ 155 BAKER, J. G.—A Synopsis of the Genera and Species of Museae . 189 Groom, P.—On Dischidia rafflesiana (Wall.). (With Plate X) . . 223 Scott, D. H., and SARGANT, E,—On the Pitchers of Dischidia raffle- siana (Wall.). (With Plates XI and XII, and 3 Woodcuts) 243 NOTES. Brown, H. T., and Morris, G. H.—A contribution to the Chemistry and Physiology of Foliage-leaves . . - - 2 2yr HEMSLEY, W. B., and ZAHLBRUCKNER, A.—The genus Tremato- vi Contents. No. XXVIII, September, 1893. PEIRCE, G. J.—On the Structure of the Haustoria of some Phanerogamic Parasites. (With Plates XIII, XIV, and XV). Bower, F. O.—On the Structure of the Axis of Lepidostrobus Brownii, Schpr. (With Plates XVI and XVII) . HARVEY GIBSON, R. J.—On the Siliceous Deposit in the Cortex of certain species of Selaginella, Spr. (With Plate XVIII) Bower, F. O.—A Criticism, and a Reply to Criticisms NOTES. MASTERS, M. T.—Synanthy in Bellis. (With Woodcut) . Acton, E. H.—Changes in the Reserve Materials of Wheat on keeping Groom, P.—The Aleurone-layer of the Seed of Grasses. FarMgR, J. B.—On Nuclear Division in the Pollen-mother-cells of Lilium Martagon. (With Woodcut) ‘ . STapF, O.—The Genus Trematocarpus CHURCH, A. H.—A Marine Fungus . No. XXVIII, December, 1893. MACFARLANE, J. M.—Observations on Pitchered Insectivorous Plants Cer II. (With Plates XIX, XX, and XXJI). . . DARWIN, F.—On the Growth of the Fruit of Cucurbita. (With Plates XXIT and XXII) . . WaGerR, H.—On Nuclear Division in the Hymenomycetes. (With Plates XXIV, XXV, and XXVI) . . . MASSEE, G.—On Trichosphaeria Sacchari. (With Plate XXVII) PAGE 2g! 329 355 367 381 383 387 392 396 399 403 459 489 515 INDEX. PAGE A. ORIGINAL PAPERS AND NOTES. AcToN, E. H.—Changes in the Reserve Materials of Wheat onkeeping 383 BAKER, J. G.—A Synopsis of the Genera and Species of Museae . 189 Bower, F. O. On the Structure of the Axis of Lepidostrobus Brownii, Schpr. (With Plates XVI and XVII). . 329 A Criticism, and a Reply to Criticisms . . . . . 367 BREBNER, G.—.See Scott. Brown, H. T., and Morris, G. H.—A contribution to the Chemistry and Physiology of F oliage-Leaves . 271 CAMPBELL, D. H.—On the development of Azolla liculoides (Lam. (With Plates VII, VIII, and IX) . 155 CHURCH, A. H.—A Marine Fungus . . 399 CoRMACK, B, G.—On a Cambial Development i in Equisetum (With Plate VI). 63 DARWIN, F.—-On the Growth of the Fruit of Cucurbita. (With Plates XXII and XXIIT) . . 459 FARMER, J. B.—On Nuclear Division in the Pollen-mother-ell of Lilium Martagon. (With Woodcut) . . 392 GREEN, J. R.—On Vegetable Ferments .. . . . 83 Groom, PERCY. Botanical Notes: No. 4. On the Velamen of Orchids... 143 » No.5. The Influence of External Conditions on "the Form of Leaves . . : 152 On Dischidia rafflesiana (Wall.). ” (With Plate X) . - +. 2323 The Aleurone-layer of the Seed of Grasses . . 387 HARVEY GIBSON, R. J.—On the Siliceous Deposit in the Cortex of certain species of Selaginella, Spr. (With Plate XVIII) . 355 HEMSLEY, W. B.,and ZAHLBRUCKNER, A.—The Genus Trematocarpus 289 MACFARLANE, J. M.—Observations on Pitchered Insectivorous Plants (Part IT). (With Plates XIX, XX, and XXI). . 403 MASSEE, G.—On Trichosphaeria Sacchari. ~ 8 ew BIS MASTERS, M. T.—Synanthy in Bellis. (With Woodcut) . . - 381 Morris, G. H.—See Brown OVERTON, E .—On the Reduction of the Chromosomes i in ‘the Nuclei lants . 139 PEIRCE, G. J.—On the Structure of the Haustoria of some Phane- rogamic Parasites. (With Plates XIIT, XIV, and XV) . 23g! SARGANT, E.— See Scott Index. PAGE SEWARD, A. C.—On the Genus Myeloxylon (Brong.). (With Plates I and II). . I Scott, D. H., and BREBNER, G. —On the Secondary Tissues i in certain Monocotyledons. (With Plates III, IV, and V) . . a1 Scotr, D. H., and SARGANT, E.—On the Pitchers of Dischidia rafflesiana (Wall. ). cuts) Starr, O.—The Genus Trematocarpus . A.—On the resisting Vitality of the Spores of Bacillus Megs terium to the condition of dryness. WaceErR, H.—On Nuclear Division in the Hymenomycete. Plates XXIV, XXV, and XXVI) . . . Swan, A (With Plates 2 XI and XII, and 3 Wood- 243 396 1§3 (With 489 ZAHLBRUCKNER, A.—Sce Hemsley. B. LIST OF ILLUSTRATIONS. a. PLATES. I, II. IIl, IV, V. VI. VII, VII, IX. X. XI, XII. XIII, XIV, XV. XVI, XVII. XVII. XIX, XX, XXL XXII, XXIII. XXIV, XXV, XXVI. XXVII. On Myeloxylon (SEWARD). Secondary Tissues in Monocotyledons (ScoTT BREBNER). On Equisetum (CORMACK). On Azolla filiculoides (CAMPBELL). On Dischidia rafflesiana (GROOM). On Dischidia raffiesiana (SCOTT and SARGANT). Haustoria of Phanerogamic Parasites (PEIRCE). On Lepidostrobus Brownii (BOWER). Siliceous Deposit in Selaginella (HARVEY GIBSON). On Pitchered Insectivorous Plants (MACFARLANE). On the Growth of the Fruit of Cucurbita (DARWIN). On Nuclear Division in the Hymenomycetes (WAGER). On Trichosphaeria Sacchari (MASSEE). and 6. WoopcuTs. 1-3. Dischidia rafflesiana (ScoTT and SARGANT) . . 263-5 4. Synanthy in Bellis (MASTERS) . . 382 . Nuclear Division in the Pollen-mother-clls of Lilium 1 Martagon > (FARMER) 394 On the Genus Myeloxylon (Brong.). BY A. C. SEWARD, M.A., F.GS., Lecturer in Botany in the University of Cambridge. —oo— With Plates I and II. —eo— N Myeloxylon' we have one of those genera of palaeozoic plants with which palaeobotanists have long been familiar, but as to whose botanical affinity the balance of opinion appears to be fairly equally divided. Numerous examples have been figured from English, German, and French localities, but none with tissues sufficiently well- preserved to admit of a complete examination of their anatomical characters. Without claiming for the specimens described in the present paper that they settle the botanical position of the genus, I hope to show that they afford further evidence in support of the view that Myeloxylon agrees more closely with recent Cycads than with Ferns. Before considering our new material in detail, it will be well to review the descriptions of previous writers and note the arguments advanced in support of the different opinions as to the relation of A/yeloxylon to recent plants. 'T use this name because it has been adopted by Solms-Laubach in his ‘ Einleitang in die Paldophytologie,’ as better known than the generic name of Stencelia, although the latter has ten years’ priority according to Goeppert and Stenzel (Die Medulloseae, p. 10 [Palaeontographica, vol. XXVIII. 1881]). [Annals of Botany, Vol. VII. No. XXV. March, 1893.) B f 2 Seward.—On the genus Myeloxylon (Brong.). In Corda’s great work, Flora der Vorwelt! (1845), a figure is given of a transverse section of a plant, from Radnitz in Bohemia, under the name of Palmacites carbonigerus. As the name implies, this was considered to be a Palm. In his description of the specimen Corda points out that much of the bundle-tissue has been destroyed, and the spaces filled with mineralizing material. In some places (Figs. 4 and 5, Pl. XX.) sclerenchymatous elements are shown in close con- nection with the vascular bundles. The tracheids are described as scalariform: no mention is made of mucilage- canals, but in Fig. 5 Corda has represented what we may in all probability regard as such. This species of Palmacttes bears a strong resemblance to Myeloxylon (Myelopteris) radiata. In 1832 Cotta? instituted three species of Medullosa ; M. elegans is the only one with which we are at present concerned. This species is recorded from Rothliegende (Permian) rocks near Chemnitz and Kohren. In the Robert Brown collection in the British Museum is a specimen which was no doubt cut from the same piece as the section figured by Cotta in Pl. XII. Fig. 2; in this section a number of dark lines of crushed cells are seen in the parenchymatous ground- mass surrounding small ‘islands ’ of mineralized tissue. This mode of fossilization is fairly common in A/yeloxylon and well marked in some of the examples to be described later. Brongniart, in his Tableau des genres de végétaux fossiles, changes the name Medullosa to Myeloxylon, and classes Myeloxylon elegans as a doubtful Monocotyledon. Goeppert * describes the hypodermal tissue of Myeloxylon as wood ; he considers the dark lines in the ground-tissue as part of the natural structure of the plant and not as an accident of ‘ Corda, Beitrage zur Flora der Vorwelt, Pl. XIX. Fig. 2. * Cotta, Die Dendrolithen, Pl. XII. Figs. 1 and 2. * Brongniart, A., Tableau des genres de végétaux fossiles, considérés sous le point de vue de leur classification botanique et de leur distribution géologique (Dictionnaire universe] d'Histoire Naturelle, vol. XIII. p. §9 [1849]). * Goeppert, Die fossile Flora der Permischen Formation, p. 218 (Palaconto- graphica, XII. 1864-1865). Seward.—On the genus Myeloxylon (Brong.). 3 mineralization. The tracheids are described as scalariform and reticulate. In conclusion Goeppert refers Myeloxylon elegans to those plants which must be looked upon as proto- types or synthetic types; he recognises Ferns, Gymnosperms, and Monocotyledons as represented in certain structural details of this palaeozoic species. Binney ', in 1872, refers to Medullosa elegans of Cotta as the rachis of a Fern or of a nearly-allied plant. In 18737 Williamson refers the same plant to the Ma- rattiaceae: Schimper, on the other hand, classes Myeloxylon with the Cycads. In 18763 Renault contributed an important paper in which a number of silicified specimens of Myeloxylon (Myelopterts of Renault, Stenzelia of Goeppert) from Autun and Saint Etienne are figured and described in detail. Several of the French specimens are much larger than any found in English rocks. The vascular bundles, which, especially in the small petioles, are arranged in fairly con- centric lines, Renault describes as consisting of large scalari- form vessels with smaller barred and spiral tracheids: the vacant space, which occurs in each bundle next to the group of xylem-elements, is referred to as a gum-cavity. In Plate IV. Fig. 27, one of these spaces is shown containing several cells or ‘tubes’ with their walls considerably thickened ; these are certainly not such elements as one would expect to find forming part of the phloém which originally occupied the vacant spaces in each bundle. Probably these so-called gum- cells with thick walls have found their way into the cavity left by the decay of the phloém. In a later work, Renault * makes no mention of the thick-walled cells, and speaks of the bast- part of the bundles as nearly always absent. Certain varia- tions in the arrangement of the hypodermal prosenchyma have ’ Binney, Proc. Lit. and Phil. Soc. Manchester, vol. XI. * In a communication to the Brit. Assoc. meeting at Bradford. > Renault, Recherches sur les végétaux silicifiés d’Autun—étude du genre Myeloplerts (Mém. par divers savants; Acad. des Sci., Instit. de France, vol. XXVII [1876)). * Cours de botanique fossile, vol. III. p. 162 (1883). . B 2 4 Seward.—On the genus Myeloxylon (Brong.). been made use of by Renault as a basis of classification: in one type, Myelopteris Landriotti, the fibrous bundles of the hypoderm are circular, elliptical, or reniform ; in the second type, 7. radiata, they are flattened and arranged as radiating bands of sclerenchymatous tissue. Our English specimens agree more closely with the 7. radiata type. Whilst ad- mitting a few points of difference between Myelopteris and recent Ferns, Renault concludes that its true position is with the Marattiaceae. One of the arguments considered by him of great weight in favour of this decision is the common associa- tion of Alethopteris-leaflets and J/yelopteris-petioles ; and in one casearachis of Alethopteris aquilina is figured showing the same structure as that of A/yelopteris. The force of this and other arguments will be considered at the conclusion of these notes. Before passing on to Williamson’s description of Myeloxylon, 1 may briefly refer to a specimen in the British Museum collection! which throws a little more light on the structure of the vascular bundles. This specimen, unfor- tunately with no record of locality, came in all probability from one of the places from which Renault’s silicified speci- mens were obtained: its general structure and mode of preservation strongly support this view. In Fig. 1, where I have represented one bundle and two canals, a number of thick-walled elements are clearly shown at s in contact with the xylem, and at p what we may probably consider as one of the protoxylem-tracheids. In the space next to the pro- toxylem are traces of torn and delicate tissue (a2), no doubt remnants of phloém: surrounding the phloém half of the bundle is a sheath of small parenchymatous cells. In his seventh memoir? on the Organization of the fossil plants of the Coal-measures, Prof. Williamson gives some account of the history of A/yelopteris and describes a number of specimens from the English Coal-measures. In these ' For access to specimens in the British Museum my thanks are due to Mr. Carrathers. ? Williamson, On the organization of the fossil plants of the Coal-measures, Pt. VII. Phil. Trans. Royal Society, 1876.