Wwe ee pe eer Fa SPR et he ow » a Sb A —————— eC a 4. Digitized by the Internet Archive in 2009 with funding from Ontario Council of University Libraries | htto://www.archive.org/details/transactionspro21bota 7 a. P - J . My — = Feel Lae | TRANSACTIONS AND PROCEEDINGS OF THE BOTANICAL SOCIETY OF EDINBURGH. ANSACTIONS AND PROCEEDINGS OF THE BOTANICAL SOCTETY OF EDINBURGH. VOLUME XxXI. INCLUDING SESSIONS LXI.—LXIV, (1896-1900), WITH NUMEROUS ILLUSTRATIONS, EDINBURGH : PRINTED FOR THE BOTANICAL SOCIETY, MDCCCC, CONTENTS OF VOL. XXI. PAGE OFFICE-BEARERS, 1896-97, 1897-98, 1898-99, 1899-1900, i., ix., XVii., xxix. AccounTs, 1895-1896, 1896-97, 1897-98, 1898-99, Vi, Xl., NIX. KANT, PRESIDENT’S ADDRESS, 1896 : : Experiments with Nitragin. By W bert Somerv ante D. Gie., D.Sc. Bacteria of the Soil. By R. S. MacDougall, M.A., B.Sc. : Excursion of the Scottish Alpine Botanical Club : Clova. By Dr. William Craig ; : : : : Photomicrography of Opaque saad eines hy R. A. Robertson, M.A., B.Sc. i P gee ; : Bohalosicn Structure of Fossil roods Part I. (with two Plates). By R. A. Robertson, M.A., B.Sc. : : A Method of Injection- eee Plant Haccake sat By R. A. Robertson, M.A., B.Sc. . ‘Pyrus Aria and its Saeaiies in Arran. By ag: D. heeedeeedaee Gleichenias. By P. C. Waite PRESIDENT’S ADDRESS, 1897 ; : : : Girth of Coniferous Trees at Braemar (w ith Mate By R. Turnbull, B.Se., and P. C. Waite : Diameter-increment of the Wood of Conifer ous ie at Braniar (with Plate). By R. Turabull, B.Sc. Excursion of the Scottish Alpine Botanical Club to Killin, B y Dr. William Craig . : : : Apodya lactea, Cornu (with Plate). ts R. Turnbull, B.Se. Relation between the Colour of Daffodils and the Composition of the Soils in which they are grown. By A. P. Aitken, D.Sc. . Hybrid Violas. By J. Grieve . Astragalus alpinus albus. By R. Tasty Hybrid Veronica. By R. Lindsay PRESIDENT’S ADDREss, 1898 Fusion of Nuclei among Plants. By P. Eagel M. ‘ Andromeda Polifolia, Linn. By Symington Grieve . : Development of Quadrifoliar Spurs in Pinus Laricio, Poir fiat Plate). By A. W. Borthwick, B.Sc. Interfoliar Buds in Pines. By A. W. Borthwick, B. Se. Micro-Methods. By A. Lundie : Contact Negatives for the Comparative Study of W abs (with Pl: ait) By R. A. Robertson, M.A., B.Sc. : : : First Record of Plants from Hepes Island, Barentz Sea. Collected by W. S. Bruce : : , Ferns, Mosses, and Lichens of Bek By Bait G. M‘Conachie CONTENTS PAGE Flora of West Inverness. By S. M. Macvicar . : ; ‘ . es Abnormal Conjugation in Spirogyra (with two Plates). By R. A. Robertson, M.A., B.Se. : . ‘ . : y . , 86 Histology of some Fossil Woods. Part IT. (with Plate). By R. A. Robertson, M.A., B.Sc. . ; : : : ; Pree) Witches’ Broom of Pinus Sylvestris. By A. W. Borthwick, B.Sc. . 196 Botanical Notes of a Tour in Upper Engadine and South-East Tyrol by three Fellows of the Edinburgh Botanical Society. By Rev. G. Gunn, M.A. ; - 198 Germination of See a of Ciena Manguant Baka (with Plate). By J. H. Wilson, D.Sc... F - : : 5 PF wi) i teed Discovery of Gentiana nivalis, Linn., in Sutherlandshire. By Dr. J. Lowe . : ; ; 3 : Le Occurrence of Ascoidea rubpseoe! Boas in Scotland. By J. A. Terras, B.Sc. . : F ; ‘ 2 LeeLee Exhibits shown at Meeting of ith Mag 1399. By Prof. Scott Elliot, M.A., B.Sc. . : 218 Obituary Notice of the late Malcolm Dupe, Vic M. H. By R Digi 220 Obituary Notice of the late Dr. George C. Wallich. By the President 222 Obituary Notice of the late Dr. James Edward Tierney Aitchison, Surgeon-Major Bengal Army. By J. Rutherford Hill A 3), 224 PRESIDENT’S ADDRESS, 1899. i ‘ ; : < : . 233 Tree Measurements (with Plates) By C. E. Hall . : 2 rh 245 Additional Notes on Andromeda Polifolia, Linn. By Symington Grieve 258 Excursion of the Scottish Alpine Botanical Club to Kirkby Lonsdale. By Dr. William Craig. 270 Obituary Notice of Rev. George Gur M. A. By et David Paul, NM. A,, LED... 277 Visit to the Dovrefjeld, Norway, By Foliti Moutguneiis Bell, W. 8. 281 Variations in Lycopodium clavatum, Linn. (with Plates). By R. A. Robertson, M.A., B.Sc. . , 290 Mehnert’s (1) Principle of “Time Displscamene rt (2) anaitied n ‘ds development of the Sporophyte. By R. A. Robertson, M.A., B.Sc. 298 Artemisia stelleriana, Boss., in Scotland. By G. Claridge Druce, M.A. 307 Witches’ Brooms. By R. A. Robertson, M.A., B.Se. : ; 313 Germination of Winter Buds of Hydtochauis Morsus- Ran. By J. A. Lerras; B.Sc. . 2 3 : : . ‘ ‘ Parte fit.’ Potentille (with Plates). By R. A. Robertson, M.A., B.Se. . i Bee. Relation between Lenticels and Adventitious Roots of Solanum Dulcamara (with two Plates). By J. A. Terras, B.Sc. . 341 Contributions to the Flora of Spitsbergen, especially of Red Fiord, from the collections of W. S. Bruce, F.R.S.G.S. By R. Turnbull, B.Se. ; : : : , : : < 0 4858 APrPrENDIX— Objects and Laws of the Society : : : . 359 Roll of the Society, corrected to Novetsber. 1900 : : «2865 List of Publication Exchanges . , ‘ . ; : >» iota INDEX . ; ‘ . ; ‘ ¢ . ‘ : ; sake TRANSACTIONS AND PROCEEDINGS OF THE BOTANICAL SOCIETY OF EDINBURGH. SESSION LXI. MEETING OF THE Society, November 9, 1896. Dr. A. P. ArrKen, President, in the Chair. The following Officers of the Society were elected for the Session 1896-97 :— PRESIDENT. ANDREW P. AITKEN, M.A., D.Sc., F.R.S.E. VICE-PRESIDENTS. Colonel Frep. BatLey, R.E. ANDREW SEMPLE, M.D., F.R.C.S.E. Professor F. O. Bower, Sc.D., Rospert TurNnBuLy, B.Sc. F.R.SS. L. & E., F.L.S. COUNCILLORS. W. Bonnar. | SYMINGTON GRIEVE. Sir ALex. Curistison, Bart., M.D. | J. Rurwerrorp HI. Wituram Craig, M.D., F.R.S.E.,| Commander F. M. Norman, R.N. F.R.C.S.E. Rev. Davip Pau, M.A., LL.D. T. CuTHBERT Day, | Witiram Watson, M.D. Professor Cossark Ewart, M.D., | F.R.SS. L. & E. | Honorary Secretary—Professor Sir DouGuas MactaGan, M.D., LL.D., Hon. V.-P.R.S.E. Honorary Curator—The Proressor oF Borany. Foreign Secretary—ANDREW P. ArrKeN, M.A., D.Se., F.R.S.E. Treasurer—RicHarD Brown, C.A. Assistant Secretary—James ADAM TerRas, B.Sc. Artist—Francis M. Cairp, M.B., C.M., F.R.C.S.E. Auditor—Ropert C. Mitvar, C.A. TRANS. BOT. SOC. EDIN. VOL. XXI. A Issued November 1897. il TRANSACTIONS AND PROCEEDINGS OF THE LOCAL SECRETARIES. Aberdeen—Professor J. W. H. Trait, M.A., M.D., F.L.S. Argyllshire— JoHN CAMPBELL, Ledaig. Bathgate—RoseErt Kirk, M. ie F.R.C.S Beckenham, Kent—A. D. Wester. Berwick-on-Tweed—FRANcIS M. Norman, R.N. Birmingham—Grorce A. Panton, F. RS. E., 73 Westfield Road. : W. H. Witkrnson, FL. S., F.R.M.S., Manor Hill, Sutton Coldfield. Bridge of Allan—ALEXANDER Paterson, M.D. Bromley, Kent—D. T. PLayratr, M.D. Calcutta—Grorce Kina, M.D., F.R.S., Botanic Garden. s Davip Pratn, M.D., F.R.S.E., F.L.8., Botanic Garden Cambridge—ArtTuuR Evans, M.A. Chirnside—CuarLes Stuart, M.D. Croydon—A. BENNETT, F.L.S. Dehra-dun, India—JAmes SYKES GAMBLE, M.A. Dundee—Professor P. GepDpDES, F.R.S.E. a5 W. G. Sry, B.Se., Ph.D. Glasgow—Professor F, O. Bower, Sc.D., F.R.S., F.LS. i Professor J. CLELAND, M.D., F.R.S. Professor Scott-Exuiot, F.L.S. Kelso—-Rev. GEORGE GUNN, M.A., Stitchel Manse. Kilbarchan—Rev. G. ALISON. Leeds—Dr. Joun H. Witsoy, Yorkshire College. Lincoln—Gerorce May Lowe, M.D. London—WILLIAM CARRUTHERS, F.R.S., F.L.S. * EK. M. Homes, F.L.S., F.R.HL.S. a JoHn ArcurIBALD, M.D., F.R.S.E. Melrose—W. B. Boyn, of Faldonside. Otag», New Zealan: 1—Professor JAMEs Gow Biack, D.Se., University. Perth—Sir Ropert Pouar, F.R.S.E. Philadelphia, U.S.A.—Professor JoHN M. MACFARLANE, D.Se., F.R.S.E. Saharunpore, India—J. F. Dutuir, B.A., F.L.S. Silloth—Joun Leircu, M.B., C.M. St. Andrews —Professor M‘Inrosu, M.D., LL.D., F.R.SS. L. & E. Ropert A. ROBERTSON, M. AS By Se. Toronto, Ontario—W. R. RIDDELL, B. Sc., B.A. < Professor RAMSEY Wricut, M.A., B.Sc. Wellington, New Zealand—Sir James Hector, M.D., K.C.M.G., F.R.SS. L. & E. Wolverhampton—Joun Fraser, M.A., M.D. Professor H. MarsuaLL Warp, of Cambridge, and Mr. J. G. Baker, F.R.S., F.LS., Keeper of the Herbarium, Kew, were, on the recommendation of the Council, elected sritish Honorary Fellows of the Society. Professor BAYLEY Batrour informed the Society that Mr. George William Traill had presented a large collection of Diatoms to the Society. | | BOTANICAL SOCIETY OF EDINBURGH lil -Mr. CAMPBELL sent for exhibition, from the open ground of his garden at Ledaig, Argyllshire, cut blooms of JMont- bretia (sp.), Escallonia macrantha, and other half-hardy plants. The PresipENT (Dr. A. P. Aitken) delivered the opening address of the session. The President made the following announcement re- garding the Roll of the Society :— During the past year the Society has lost by death :—2 Honorary Foreign Fellows—D. Henri Ernest Baillon; Baron Ferdinand von Mueller. 2 Resident Fellows——The Rev. Thomas Anderson ; Andrew Moffat. 2 Non-Resident Fellows—James Carter; Dr. George Lawson. 1 Corresponding Member—Professor J. E. Bommer. 1 Associate—John Buchanan, C.M.G. During the same period the Society received the following accession :—1 Resident Fellow—Somerville Grieve. The Roll of the Society stands at present thus :— Honorary Fellows— Royal 3 British + Foreign 22 — 29 Resident Fellows . , ; : 4 : 126 Non-Resident Fellows . ; : : of SwkoG Corresponding Members : i ; : 50 Associates. é : : . ; : 23 Lady Associate. : : : : : 1 Lady Members. : ‘ : ‘ P 5 Total of Roll . . ‘ 370 The following paper was read :— Notes from the Royal Botanic Garden, Edinburgh. MEETING OF THE Society, Thursday, December 7, 1896. Dr. A. P. ArrKen, President, in the Chair. Mr. S. C. MAHALANOBIS, B.Sc., was elected a Resident Fellow of the Society. Intimation of the death of Ropert ELtior, a Resident Fellow of the Society, was made by the Chairman. iv TRANSACTIONS AND PROCEEDINGS OF THE Colonel F. BAiLEy exhibited a mass of tree roots taken from a water-pipe. The following papers were read :— I. Some Xerophytic ere By James A. Terras, B.Sc. IT. Notes from the Royal Botanic Garden, Edinburgh. MEETING OF THE SoctEty, Thursday, January 14, 1897. Dr. A. P. A1rken, President, in the Chair, Intimation of the death of Dr. Jonn Lerrcn, a Resident Fellow of the Society, was made by the Chairman. Miss MAppEN exhibited a number of seeds from North (Jueensland. Mr. RurHeRFORD HI 1 exhibited two species of Ti/landsia, from South America. Dr. AITKEN exhibited an apple showing carpellary proliferation. The following papers were read :— I. Experiments with “ Nitragin.” By Prof. William Somerville. II. Notes from the Royal Botanic Garden, Edinburgh. MEETING OF THE Society, Thursday, February 11, 1897. Captain Norman, R.N., in the Chair. The following papers were read :— I. Bacteria of the Soil, with special reference to Soil Inoculation. By R. Stewart MacDougall, M.A., 3c, Il, Notes from the Royal Botanic Garden, Edinburgh. BOTANICAL SOCIETY OF EDINBURGH Vv MEETING oF THE Socinry, Thursday, March 11, 1897. Dr. A. P. AIrKEN, President, in the Chair. The TREASURER submitted the following Statement ot Accounts for the Session 1895—96 :— INCOME. Annual Subscriptions, 1895-96; 62 at 15s.=£46, 10s., and 1at10s. . , : ; : : ; £47 0 0) Do., 1894-95, 2 at 15s. . ; : ere: dao” 0 Compositions for Life Membership. : 6) 6 0 Transactions. ete., sold. : : ‘ : é 5m OF 2 Subscriptions to Illustration Fund . ais 0) £60 11 2 EXPENDITURE. Printing Transactions, £44; Billets, ete., £7, 4s. . £51 4 0 Rooms for Meetings, Tea, and Hire of Screens 6: =2° ‘0 Commission paid to Collector of Subscriptions : | Ua eas Stationery, Postages, Carriages, etc. 410 0 Fire Insurance on Books, ete. : , : ; ; 05 0 Expenditure ; i eGo ke Ss Balance of Income Oar Ad £63 11 2 STaTe oF Funps. Amount of Funds at close of Session 1894-95 : oe SGt) 118) -5 Add—Increase during Session 1895-96, as above : Oe t. Amount of Funds at close of Session 1895-96 : ‘ £62 8 4 Being:—Sum in Current Account with Union Bank . : § Pie: me (ee Sum in Deposit Receipt with do. 60 0 0 Due by Treasurer : ; ‘ 12 16.8 a1 4-3 Deduct—Accounts not paid till after close of Session . , 54 15 11 62 8 4 Note.—Subscriptions in arrear, 1894-95, 15s, ; 1895-96, £5, ds, vi TRANSACTIONS AND PROCEEDINGS OF THE On the motion of Dr. Craic, seconded by Professor BaYLEY BA.rour, the report was adopted and the Treasurer thanked for his services. The following papers were read :— I, Report on the Excursion of the Scottish Alpine Botanical Club to Clova in 1896. By Dr. William Craig. II. On the Photomicrography of Opaque Stem Sections, Recent and Fossil By R. A. Robertson, M.A., B.Sc. III. Notes from the Royal Botanic Garden, Edinburgh. MEETING oF THE Society, Thursday, 8th April 1897. Dr. A. P. AirkEen, President, in the Chair. Mr. A. F. BAINBRIDGE was elected a Resident Fellow of the Society. Mr. TURNBULL exhibited a hyacinth grown in an inverted position, in a glass of water, with the inflorescence sub- merged. Mr. R. S8. MacDovuGAa.u exhibited a specimen of Bipalium Kewense found in one of the houses at the Royal Botanic Garden, Edinburgh. The following papers were read :— I. The Histological Structure of Fossil Woods. By R, A. Robertson, M.A., B.Sc. II. A Method of Injection-Staining Plant Vascular Systems. By R. A. Robertson, M.A., B.Sc. III. Notes from the Royal Botanic Garden, Edinburgh. = — BOTANICAL SOCIETY OF EDINBURGH vil MEETING Or THE Society, Thursday, May 13, 1897. Dr. A. P. AITKEN, President, in the Chair. Intimation of the death of Mr. CAMPBELL, of Ledaig, and of Mr. W. G. TRAILL, both Associates of the Society, was made by the Chairman. Mr. G. H. Ports exhibited a number of seedling Saxi- frages in pots, along with cut blooms of hybrid Primulas. Miss MappeEn exhibited a twig of nettle bearing a well- developed colony of Xeidium Urtice. Mrs. AITKEN exhibited a remarkably perfect example of a skeleton cabbage stem due to natural decay. The following paper was read :— Notes from the Royal Botanic Garden, Edinburgh. MEETING OF THE Society, Thursday, June 10, 1897. Dr. A. P. AITKEN, President, in the Chair. Mr. Symers M. M‘Vicar was elected a Non-Resident Fellow of the Society. Mr. R. Stewart MacDovucati exhibited specimens of Ash damaged by Hylesinus crenatus; of Acer attacked by Bostrichus dispar; a portion of the woodwork of an inn damaged by Callidiwm bajulum; and a number of living locusts from Natal. Mr. Rosert TuRNBULL exhibited a series of natural hybrids between the primrose and the cowslip obtained from North Berwick. Vill TRANSACTIONS AND PROCEEDINGS Mr. Srasier, of Levens, Westmoreland, exhibited a fasciated inflorescence of Hubenaria biflora, from a plant in his garden. Mr. Symincron GRIEVE exhibited pine shoots attacked by Helobius abietis and Phyllobius argentea. The following paper was read :— Notes from the Royal Botanic Garden, Edinburgh. MerKriNG oF THE Society, Thursday, July 8, 1897. Dr. Witttam Crate in the Chair. Mr. F. C. CRAWFORD was elected a Resident Fellow of the Society. Sip ARCHIBALD BucHaN Heppurn, Bart., exhibited an inflorescence of Oncidiwm Phymatocheilum, 9 feet 7 inches in length, and bearing 38 lateral branches, the longest of which reached a length of 2 feet 8 inches. The following papers were read :— I The Rare Arran Pyrus: new stations, and a new type. By Rev. D. Landsborough. IL. Pyrola uniflora in Forfarshire. By J. 5S. Miller. III. Notes from the Royal Botanic Garden, Edinburgh. -_ TRANSACTIONS AND PROCEEDINGS OF THE BOTANICAL SOCIETY OF EDINBURGH. SESSION LXII. MEETING OF THE Society, November 11, 1897. Dr, A. P. ArrKeN, President, in the Chair. The following Officers of the Society were elected for the Session 1897—98 :— PRESIDENT. Wittram Watson, M.D. VICE-PRESIDENTS. J. RUTHERFORD HILL. ANDREW SEMPLE, M.D., F.R.C.S.E. Captain F. M. Normay, R.N. Rosert TURNBULL, B.Sc. COUNCILLORS. Colonel Frep. Battey, R.E. Professor Cossark Ewart, M.D., W. Bonnar. | F.R.SS. L. & E. Witiiam Craic, M.D., F.R.S.E., | SymineTon GRIEVE. F.R.C.S.E. Rev. Davip Pau, M.A., LL.D. W. CaLpDWELL CRAWFORD. T. Bonp Spracue, M.A., LL.D., ArTuour E. Davis, Ph.D., F.L.S. F.R.S8.E. T. Curupert Day, Honorary Secretary—Professor Sir DouGtas Mactaaan, M.D., LL.D., Ex-P.R.S.E. Honorary Curator—The Proressor oF Borany. Foreign Secretary—ANDREW P. AITKEN, M.A., D.Se., F.R.S.E. Treasurer—RicHARD Brown, C.A. Assistant Secretary—JAMES ADAM TERRAS, B.Sc. Artist—Francts M. Catrp, M.B., C.M., F.R.C.S.E. Auditor—Rosert C. MILuar, C.A. TRANS, BOT. SOC. EDIN. VOL. XXI. Issued November 1898. - x TRANSACTIONS AND PROCEEDINGS OF THE LOCAL SECRETARIES. Aberdeen—Professor J. W. H. Tratt, M.A., M.D., F.L.S, Bathgate—Rosert Kirk, M.D., O.M., F.R.C.S.E. Beckenham, Kent—A. D. WEBSTER. Berwick-on- Tweed—F rancis M. Norman, R.N. Birmingham—Gerorce A, Panton, F.R.S.E., 73 Westfield Road. W. H. Wirxinson, F.L.S., F.R.M.S., Manor Hill, Sutton Coldfield. Bridge of Allan—ALEXANDER Paterson, M.D. Bromley, Kent—D. T. Puayratr, M.D., C.M. Calcutta—GerorGE Kine, M.D., F.R.S., Botanie Garden. re Davip Pratn, M.D., F.R.S.E., F.L.S., Botanic Garden. Cambridge—ARTHUR Evans, M.A. Chirnside—Cuar.es Stuart, M.D. Croydon—A. BENNETT, F.L.S. Dehra-dun, India—JAMes SYKES GAMBLE, M.A. Dundee—Professor P. GEpDpES, F.R.S.E, Glasgow—Professor F. O. Bower, Se.D., F.R.S., F.L.S. Professor J. CLELAND, M.D., F.R.S. As Professor Scorr-Euuiot, F.L.S. Kelso—-Rev. GEORGE GUNN, M.A., Stitchel Manse. Kilbarchan—Rev. G. ALISON. Lincoln—Gerorce May Lowe, M.D., C.M. London—WILLIAM CARRUTHERS, F.R.S., F.L.S. “9 E. M. Homes, F.L.S., F.R.H.S. a JOHN ARCHIBALD, M.D., F.R.S.E. Melrose—W. B. Born, of Faldonside. Otago, New Zealand—Professor James Gow Buack, D.Se., University . Oxford—Dr. GUSTAV MANN. Perth—Sir Ropert Pouxar, F.R.S.E. Philadelphia, U.S.A.—Professor Joun M. MACFARLANE, D.Se., F.R.S.E. Saharunpore, India—J. ¥. Dutuie, B.A., F.L.S. St. Andrews —Professor M‘INtosH, M.D., LL.D., F.R.SS. L. & E. Ropert A. Ropertson, M.A., B.Se. = Dr. J. H. WILSON. Toronto, Ontario—W. R. Rivet, B.Sc., B.A. ” ‘ Professor RamsEY Wricut, M.A., B.Se. Wellington, New Zealand—Sir JAMES Hector, M.D., K.C.M.G., F.R.SS. L. & E. Wolverhampton—Joun Fraser, M.A., M.D. th) 49 BOTANICAL SOCIETY OF EDINBURGH xi The TREASURER submitted the following Statement of Accounts for the Session 1896—97 :— INCOME. Annual Subscriptions, 1896-97; 60 at 15s.=£45, and lat 10s. . ; Do., 1895-96, 4 at 15s. . : Compositions for Life Membership . Transactions, etc., sold Subscriptions to Illustration Fund . Interest. on Deposits in Bank EXPENDITURE. Printing Transactions, £18, 13s. 2d.; Billets, etc., So,es00, .. : : ; : : Rooms for Meetings, Tea, and Hire of Screens Stationery, Postages, Carriages, etc. Fire Insurance on Books, etc. Expenditure Balance of Income STATE OF FuNnDs, Amount of Funds at close of Session 1895-96 Add—Increase during Session 1896-97, as above Amount of Funds at close of Session 1896-97 Being:—Sum in Current Account with Union Bank of Scotland Ltd. . £30 7 4 Sum in Deposit Receipt with do. SOC eG Due by Treasurer , : . ie = 8 £120 16 0 Deduct—Account not paid till after close of Session 2616 8 LAD ONO 5) (0) 0) jit ealal (0) Ate) 3) 1K) ao) TL alg) sal #258) 1b) al SOMO 2c (ROY Ao Oma: O sfate) (0) a Silas S69) 1 S62 8 4 Siete 4) £93 19 4 93 19 4 Note.—Subscriptions in arrear, 1895-96, £1, 10s.; 1896-97,£6, 15s. xi TRANSACTIONS AND PROCEEDINGS OF THE On the motion of Dr. WiLLIAM CraiG the report was adopted and the Treasurer thanked for his services. The Presidential address for the Session was read by Dr. A. P. AITKEN. MEETING OF THE Society, December 9, 1897. Dr. Wiutiam Watson, President, in the Chair. A communication on the Measurement of Girth of Coniferous Wood at Braemar was read by Messrs. TURNBULL and WaAITE. A paper on a Comparison of Plants with Animals was read by the PRESIDENT. MEETING OF THE SOCIETY, January 13, 1898. Dr. Witi1am Watson, President, in the Chair. The Laws of the Society were signed by Mr. F. C. CRAWFORD. A further communication on the Increment of Girth of Coniferous Trees at Braemar was read by Mr. RosBert TURNBULL, B.Sc. The report of the Scottish Alpine Botanical Club’s Excursion to Killin was read by Dr. WILLIAM Cratc, BOTANICAL SOCIETY OF EDINBURGH Xili MEETING OF THE Soctety, February 10, 1898. Dr. Wiit1am Warson, President, in the Chair. Miss R. Orrock was proposed as a Resident Fellow of the Society by Mr. Ropert TuRNBULL, B.Se., seconded by Dr. WiLLiAm Watson. Mr. Duny, of Dalkeith, exhibited a number of plants in flower in the open air, as illustrating the mildness of the season. A paper on the Changes which take place in the Nucleus of Secreting Cells was read by Miss L. H. HUte. Two caterpillars, infested with Cordyceps Militaris, trom India, were exhibited by Miss ORROCK. MEETING OF THE Soctety, March 10, 1898. Dr. ANDREW SEMPLE, Vice-President, in the Chair. Miss R. Orrock, proposed by Mr. Ropert TURNBULL, B.Sc., seconded by Dr. Wm. Watson, was balloted for and duly elected a Resident Fellow of the Society. A communication on Apodya lactea was read by Mr RoBeRT TURNBULL, B.Sc., and was illustrated by means of the lantern. A communication on the Colour of Daffodils in relation to the Character of the Soil on which they grow was read by Dr. A. P. AITKEN. X1V TRANSACTIONS AND PROCEEDINGS OF THE MEETING OF THE Society, April 10, 1898. Mr. J. RurHERFORD HILL, Vice-President, in the Chair. A Herbarium of the rarer Alpine Plants collected in the neighbourhood of Braemar in 1854—55 by the late A, CROALL, Esq., was exhibited by Mr. Ropert TURNBULL, BSe. Mr. TURNBULL communicated a paper on the Flora of Franz-Josef Land, and exhibited a number of specimens collected by Mr. W. 8. Bruce, Naturalist to the Jackson- Harmsworth Polar Expedition. Mr. J. RuTHERFORD HILu read a paper on the Alkaloids of Cephaélis Ipecacuanha, and exhibited a number of specimens. Mr. J. XUTHERFORD HILL read a paper on the, Insecticidal Properties of the Flower Heads of Pyrethrwm rosewm, ~P. carneum, and P. cinerariefolium. Specimens of Douglas Fir attacked by Phoma pithya were exhibited to the Society by Mr. Matcotm Duny, of Dalkeith. MEETING OF THE Society, May 12, 1898. Dr. WILLIAM WATSON, President, in the Chair, Davip RussELL, Esq., 7 Strathearn Road, was proposed a Resident Fellow of the Society by Miss R. Orrock, and seconded by Mr. Robert TURNBULL, B.Se. A note on the Hybridisation of Violets was read by Mr. J. Grieve, who also exhibited a number of illustrative specimens. BOTANICAL SOCIETY OF EDINBURGH XV MEETING OF THE Society, June 9, 1898. Dr. WiLLIAM CraliG in the Chair. Davip Russet, Esq., 7 Strathearn Road, proposed a Resident Fellow of the Society by Miss R. Orrock, and seconded by Mr. Ropert TURNBULL, B.Se., was balloted for and duly elected. Several specimens of Cuscuta Epithymum were exhibited by Miss ORROCK. MEETING OF THE Socirty, July 14, 1898. Dr, WILLIAM WATSON, President, in the Chair. Mr, PANTLING, of the Royal Botanic Garden, Calcutta, was duly balloted for and elected an Associate of the Society. A communication on the discovery of a White variety of Astragalus alpinus, Linn., on Ben Vrackie, Perthshire, was read to the Society, and specimens of the plant were exhibited by Mr. Roperr LINDSAY. Mr. Rospert Linpsay also exhibited, in flower, specimens of a hybrid shrubby Veronica. TRANSACTIONS AND PROCEEDINGS OF THE BOTANICAL SOCIETY OF EDINBURGH. SESSION LXIIT. MEETING OF THE Society, November 10, 1898. Dr. Wm. Watson, President, in the Chair. The following Officers of the Society were elected for the Session 1898—99 :— "PRESIDENT. WiLiiaAm Watson, M.D. VICE-PRESIDENTS. Wiitiiam Craic, M.D., F.R.S.E.,| Professor Cossar Ewart. M.D.. F.R.C.S.Ed. F.R.SS. L. & E. J. RUTHERFORD HILL. | Captain F. M. Norman, R.N. COUNCILLORS. Colonel Frep. Barttey, R.E. | Dr. R. Srewart MacDovueatt, W. Bonnar. | M.A. W. CaLDWELL CRAWFORD. | Rev. Davip Pau, M.A., LL.D. Artuour E. Davis, Ph.D., F.L.S. | T. Bonp Sprague, M.A., LL.D., G. F. Scotr Exxior, M.A., B.Sc.,| | F.R.S.E. F.LS. | Rosert TURNBULL, B.Sc. SYMINGTON GRIEVE. Honorary Secretary—Professor Sir DouGLas Mactaa@an, M.D., LL.D., Ex-P.R.8.E. Honorary Curator—The Proressor oF Borany. Foreign Secretary—ANDREW P. A1rKEN, M.A., D.Sc., F.R.S.E. Treasurer—RIicHarD Brown, C.A. Assistant Secretary—JAMES ADAM TERRAS, B.Sc. Artist—FRancis M. Carrp, M.B., C.M., F.R.C.S.Ed. Auditor—Ropert C. Mituar, C.A. XVlll TRANSACTIONS AND PROCEEDINGS OF THE LOCAL SECRETARIES. Aberdeen—Professor J. W. H. Trait, M.A., M.D., F.L.S. Bathgate—Rosert Kirk, M.D., F.R.C.S.Ed. Beckenham, Kent—A. D. WEBSTER. ' A y Berwick-on- Tweed—F rancis M. Norman, R.N. Birmingham—GeorGE A. PANTON, F.R.S.E., 73 Westfield Road. i. W. H. Wivxrnson, F.L.S., F.R.M.S., Manor Hill, Sutton Coldfield. Bromley, Kent—D. T. Puayratr, M.D., C.M. Calcutta—GrorGE Kine, M.D., F.R.S., Botanic Garden. ‘ Davip Prain, M.D., F.R.S.E., F.L.8., Botanic Garden. Cambridge—ARTHUR Evans, M.A. Cardiff—S. C. MAHALANOBIS, B.Sc. Chirnside—CHARLES Stuart, M.D. Croydon—A. BENNETT, F.L.S. Dehra-dun, India—JAMES SYKES GAMBLE, M.A. Dundee—Professor P. GeppEs, F.R.S.E. | Glasyow—Professor F, O. Bower, Sc.D., F.RS., F.L.S. Professor J. CLELAND, M.D., F.R.S. ae Professor Scotr-Enuiot, F.L.S8. Kelso—-Rev. GrorGre GuNN, M.A., Stitchel Manse. Kilbarchan—Rev. G. ALISON. Lincolm—GerorGE May Lowe, M.D., C.M. London—WILLIAM CARRUTHERS, F.R.S., F.L.S. # E. M. Houmes, F.L.S., F.R.H.S. . JOHN ARCHIBALD, M.D., F.R.S.E. Melrose—W. B. Boyn, of Faldonside. Otago, New Zealand—Professor James Gow Brack, D.Se., University. Perth—Sir Ropert Puuwar, F.R.S8.E. Philadelphia, U.S. A.—Professor JouN M. MACFARLANE, D.Se., F.R.S.E. Saharumpore, India—J. F. Dutuir, B.A., F.L.S. St. Andrews —Professor M‘Intosu, M.D., LL.D., F.R.SS. L. & E. 7 Rosert A. Ropertson, M.A., B.Se. A, Dr. J. H. WILson. , Toronto, Ontario—W. R. RippEti, B.Sce., B.A. rf a Professor RaMseEY Wricut, M.A., B.Se. Wellington, New Zealand—Sir James. Hecror, M.D., K.C.M.G., F.R.SS. L. & E: Wolverhampton—Joun Fraser, M.A., M.D. BOTANICAL SOCIETY OF EDINBURGH X1X The TREASURER submitted the following Statement of Accounts for the Session 1897—98 :-— INCOME. Annual Subscriptions, 1897-98; 60 at 15s.=£45, and fati0s.... 3 Do., 1896-97, 3 at lis. . Transactions, ete., sold Subscriptions to Illustration Fund . Interest on Deposits in Bank EXPENDITURE. Printing Billets, etc. : Rooms for Meetings, Tea, and Hire of Screens Stationery, Postages, Carriages, etc. Fire Insurance on Books, ete. Expenditure : Balance of Income, subject to awircts of Printing Transactions for Session 1897-98 (about £20) STATE oF Funps. Amount of Funds at elose of Session 1896-97 Add—Increase during Session 1897-98, as above Amount of Funds at close of Session 1897-98, subject to Expense of Printing Transactions (about £29) Being:—Sum in Current Account with Union Bank of Scotland Ltd. . pO A Sum in Deposit Receipt with'do. 13110 7 SIsG LF Less—Due to Treasurer . ; 218 9 Note.—Subscriptions in arrear, 1896-97, £2, 5s. ; £45 10 0 Bh. © 12-0 south PEO Es 7 AS 4 WT Boer ety hs WF 6 11 11 Jo 8 Oo: Ss) 0 £18. 14° 2 aoe St 16 BY oan Af Aaa | £93 19 4 39 3 6 £133 10 1355 2 10 1897-98, £3, 14s. XX TRANSACTIONS AND PROCEEDINGS OF THE On the motion of Dr. WILLIAM CraiG the report was adopted and the Treasurer thanked for his services. Dr. Craic then referred to the recent death of Dr. AITCHISON, a well-known and valued Member of the Society. The Presidential address for the Session was read by Dr. WATSON. On the motion of Dr. Cratc, seconded by Rev. A. B. Morris, a vote of thanks was conveyed to the President for his address. Mr. RuTHERFORD HILL exhibited to the Society a number of winter buds of Anacharis alsinastrwum. Mr. F. C. Crawrorp exhibited a plant of Primula farinosa, gathered by himself at the West Linton station, where, as he assured the Society, the plant is not yet extinct, though its existence is threatened by the en- croachments of cultivation. MEETING OF THE Society, December 8, 1898. Abe Dr. Witi1am Watson, President, in the Chair. Mr. A. W. Bortuwick, B.Sec., was proposed as a Resident Fellow of the Society by R. A. Ropertson, M.A., B.Sc., and seconded by JAMES A. TERRAS, B.Sc. Mr. ALEX. Morton, B.Se., was proposed as a Resident Fellow of the Society by R. TURNBULL, B.Se., and seconded by F. C. Crawrorp, F.R.S.E. Dr. Craic called attention to the death of Dr. ALLMAN, a distinguished Fellow of the Society. BOTANICAL SOCIETY OF EDINBURGH =X Dr. R. Stewart MacDouea tt, M.A., exhibited a number of Apples injured by Phyllopertha hortieola, two specimens of Birch attacked by Scolytus Ratzeburgii, and other two in which the Scolytus had been in turn attacked by wood- peckers. Mr. J. Ruruerrord Hitt exhibited a large collection of Arrow and Ordeal Poisons, as well as a number of Poisoned Arrows. Mr. J. Rurwerrorp Hitt communicated an Obituary Notice of the late Dr. J. E. T. Atrcuison, LL.D., C.LE., F.RS. Mr. Percy Groom, F.L.S., communicated a paper entitled The Significance of Nuclear Fusions in Plants. MEETING OF THE SOCIETY, January 12, 1899. Dr. Wiui1am Warson, President, in the Chair. Mr, A. W, Borruwick, B.Sc., proposed by R. A. Roperr- son, M.A., B.Sc., seconded by JAMES A. Terras, B.Sc.; and Mr. ALEX. Morton, B.Sc., proposed by R. TuRNBULL, B.Sc., seconded by F. ©. Crawrorp, F.R.S.E.—were balloted for and duly elected Resident Fellows of the Society. They thereafter signed the Laws of the Society. The PRESIDENT exhibited to the Society specimens of Tremellodon gelatinosum. Dr. R. Stewart MacDovGat, M.A., exhibited specimens of Goes tigrina, with examples of the damage inflicted by it on timber. Mr. SYMINGTON GRIEVE read a communication entitled Notes on Andromeda polifolia, Linn., with special reference to a new station for the plant in Liddesdale. XXil TRANSACTIONS AND PROCEEDINGS OF THE Mr. A. W. Bortuwick, B.Sc., read a communication on the occurrence of Quadrifoliar Spurs in Pinus Laricio, Poir. Mr. A. W. Bortuwick, B.Sc., read a further communica- tion on the Interfoliar Buds of Pinus Laricio, Poir. Mr. R. A. Ropertson, M.A., BSe., communicated a paper entitled Some new Micro-Methods, by ALEX. LUNDIE. Mr. R. A. Ropertson, M.A., B.Sc., read a communication on the Value of Contact Negatives in the Comparative Study of Woods. MEETING OF THE SoctEty, February 9, 1899. Dr. WittrAm Watson, President, in the Chair. Miss PEARSON exhibited to the Society a collection of Paintings of French and Swiss Flowers. Myr. J. Ruruerrorp Hitt exhibited a Double Orange, and also a plant of Zaraxacum officinale showing a peculiar formation of roots. Miss L. Huig read a communication entitled Notes on the Relations existing between the Cell Plasm and the Nucleus in Drosera Tentacles. The paper was illustrated by means of the lantern. Mr. R. TurNBULL, B.Sc., communicated a paper by W. S. Bruce, of the Jackson-Harmsworth expedition, entitled A First Record of Plants from Hope Island, Barentz Sea. The PRESIDENT communicated a paper by the Rev. G. M‘Conacuig, of Rerrick, entitled Notes on the Ferns, Mosses, and Lichens of the Parish of Rerrick. i ate aral BOTANICAL SOCIETY OF EDINBURGH Xxill MEETING CF THE Soctety, March 9, 1899. Dr. WiturAM Watson, President, in the Chair. Mr. Matcotm Dunn exhibited the following early flowering Plants and Shrubs sent him from the garden of Mr. Maxwett of Munches:—Andromeda floribunda: Alnus incana aurea: Buxus arborea; Corylus avellana, and its varieties aurea, atropurpurea, and variegata: Crypto- meria Japonica; Cornus mascula; Hammamelis Japonica : Jasminum nudiflorum; Laurustinus viburnum; Mahonia agquifolia; Pyrus Maulei; Pyrus Japonica, three varieties : Skimmia Japonica; S. fragrans; Taxus baccata; Nuttalia ceraforniis. He also exhibited the following Plants from the garden of Dalkeith Palace:—Amygdalis Davidianus, alba and rosea: Andromeda floribunda; A. Japonica ; Arbutus Andrachne : A. Unedo; Azara microphylla; Berberis Darwinii: B. Mahonia: Busus sempervirens; Chimonanthus fragrans, Choisya ter- nata; Coryllus avellana; Cornus mas; C. florida; Cryptomeria Lobbii; Cupressus macrocarpa, cones; C. Sinensis; Cydonia Japonica, four varieties; Daphne Laureola; D. hybrida: D. Mezereum, four varieties: Erica herbacea, four varieties: E. Mediterranea; Eleagnus glabra variegata; Edgeworthia papyrifera; Ercilla spicata; Exchorda grandiflora; Garrya elliptica, male and female; Hammamelis arborea; H. Japonica; Juniperus Communis; J. Sinensis, var. aurea: Jasminum nudifiorum; Laurus nobilis; Ligustrum ovali- folium aureum; Mahonia aquifolia; Viscum album, with berries; Phillyrea latifolia; Pernettia mueronata; Rhodo- dendron Nobleanum; R. precox; Salix caprea pendula: S. viminalis; Skimmia Japonica; S. Formani, male and female, also with berries; Viburnum rugosum; V. tinus: Vinca minor, three varieties; Taxus baccata: Hypatica angulosa; Sisyrinchium grandiflorum; Single and Double Snowdrops; Crocus, vars.; Apricot, scarcely opened: also Peach and Pear in the same condition. Mr. SyMINGTON GRIEVE read a communication by Mr. Symers M. Macvicar, entitled Notes on the Flora of West Inverness. XX1V_ TRANSACTIONS AND PROCEEDINGS OF THE Mr. R. A. Roperrson, M.A., B.Se., read a communica- tion entitled Notes on a Number of Abnormal Modes of Conjugation in Spirogyra. Mr. R. A. Ropertson M.A., B.Sc., communicated the second part of his paper on Fossil Stems. Mr. A. W. Borruwick, B.Sc., read a paper entitled Notes on the Witches’ Broom of Pinus sylvestris. MEETING OF THE Society, April 13, 1899. Dr. WitittAM Watson, President, in the Chair. Dr. J. H. Witson exhibited to the Society a series of coloured drawings, by himself, of Fungi, chiefly from Aberdeenshire. Rev. Dr. D. Paut, M.A., exhibited a series of water-colour drawings, illustrative of some of the rarer Fungi. tev. GEORGE GuNN, M.A., communicated a paper entitled The Botany of a Tour in the Upper Engadine and South- East Tyrol. Dr. J. H. Witson read a paper on the Germination of the Seeds of Crinwin Macowanii. The paper was illustrated by means of the lantern. Dr. J. H. Witson exhibited a series of lantern slides showing the mode of growth in Agarieus (Collybia) buty- raceus and Phallus impudicus. Dr. Craic read a communication by Dr. Joun Lowe, entitled A Note on the Discovery of Gentiana nivalis in Sutherlandshire. i _— Te BOTANICAL SOCIETY OF EDINBURGH XXV MEETING OF THE Society, May 11, 1899. Dr. WixuiIAM Craic, Vice-President, in the Chair. Professor G. F. Scott-E.LLior exhibited a herbarium of Spanish Plants. Professor G. F. Scott-E.Luiot also exhibited a number of the rarer Mosses and Fungi from the Glasgow district. Mr. James A. Terras, B.Sc., read a communication entitled Notes on the occurrence of Ascoidea rubescens, Bref., in Scotland. MEETING OF THE SociEtTy, June 8, 1899. Dr. WILLIAM CraiG, Vice-President, in the Chair. Mr. WILLIAM Boyp exhibited several specimens of Poa Suecica, an introduced grass which has established itself in the neighbourhood of Galashiels. Mr. MILNE exhibited a number of remarkably fine specimens of Luphorbia Myrsinites. Mr. hk. Linpsay read an Obituary Notice of the late Mr. Maucotm Duyy. A specimen of Hormiscium pithyophyllum found growing on Yew trees in the Clachan Avenue, Roseneath, by Mr. JoHN PaTeErRsON, and sent to the Society by Professor Scotr-ELLIoT, was exhibited to the Society by the ASSISTANT-SECRETARY. XXV1 TRANSACTIONS AND PROCEEDINGS MEETING OF THE SoctEetTy, July 13, 1899. Dr. WILLIAM WATSON, President, in the Chair. The PRESIDENT exhibited to the Society a specimen of Hierochloe borealis, sent by Rev. G. M‘Conacuig, of Rerrick, from a new station in Kirkcudbrightshire. Mr. R.. Turnsputy, B.Se., exhibited an inflorescence of Nasturtium officinale showing flowers, each petal of which bore in its axil a small flower with only four stamens, the antero-posterior pairs of stamens being replaced by a single stamen each, while in the large flower the stamens were normal. The specimens were obtained at North Berwick, and were abundant in the particular situation whence they were taken. The PRESIDENT read an Obituary Notice of the late Dr. GEORGE C. WALLICH. ' y . “ * , : 9 - ) x 14 al 7 | “ jl . ’ G TRANSACTIONS AND PROCEEDINGS OF THE BOTANICAL SOCIETY OF EDINBURGH. SESSION LXIV. MEETING OF THE Socrety, Thursday, November 9, 1899. Dr. Wu. Watson, President, in the Chair. The following Officers of the Society were elected for the Session 1899-1900 :— PRESIDENT. Rey. Dr. DAviD PAUL, M.A. VICE-PRESIDENTS. WILLIAM Bonnar. | WittiaM CraiG, M.D., F.R.S.E., SYMINGTON GRIEVE. le EROS: wd, Professor Cossark Ewart, M.D., F.R.SS. L. & E. COUNCILLORS. Colonel Frep. BatLey, R.E. | ALEXANDER SOMERVILLE, B.Sc., W. CaLpWELL CRAWFORD. F.L.S. Arruur KE. Davis, Ph.D., F.L.S. | T. Bonp Spracur, M.A., LL.D., G. F. Scotr Extiot, M.A., B.Sc., F.R.S.E. F.L.S. RosBerT TURNBULL, B.Sc. Dr. R. Srewart MacDovuaatt, | Professor J. W. H. Trait, M.A., M.A., D.Se. M.D., F.L.S. Witiiam Watson, M.D. Honorary Secretary—Professor Sir Dovucias Macta@ay, M.D., LL.D., Ex-P.R.8.E. Honorary Curator—The Proressor oF Borany. Foreign Secretary—ANDREW P. AITKEN, M.A., D.Sc., F.R.S.E. Treasurer—RIcHARD Brown, C.A. Assistant Secretary—JAMES ADAM TERRAS, B.Sc. Artist—FRancis M. Cairp, M.B., C.M., F.R.C.S.Ed. Auditor—Ropert C. MILLAR, C.A. XXX TRANSACTIONS AND PROCEEDINGS OF THE LOCAL SECRETARIES. Aberdeen—Professor J. W. H. Tratt, M.A., M.D:, F.L.S. Bathgate—Rosert Kirk, M.D., F.R.C.S.Ed. Beckenham, Kent—A. D. WEBSTER. Berwick-on- Tweed—FRrancis M. Norman, R.N. Birmingham—Georce A. Panton, F.R.S.E., 73 Westfield Road. A W. H. Witxisson, F.L.S., F.R.M.S., Manor Hill, Sutton Coldfield. Bournemouth—Joun ARCHIBALD, M.D., F.R.S.E. Bromley, Kent—D. T. Puayrarr, M.D., C.M. Calcutta—Davip Prat, M.D., F.R.S.E., F.L.S., Royal Botanic Garden. Cambridge—Artuur Evans, M.A. Cardiff—S. C. Manaranosis, B.Sc. Chirnside—CHARLES Stuart, M.D. | Croydon—A. BENNETT, F.L.S. Dundee—Professor P. Gepprs, F.R.8.E. East Liss, Hants.—JAMes SYKES GAMBLE, M.A. Glasgow—Professor F. O. Bower, Se.D., F.R.S., F.L.S. _ Professor J. CLELAND, M.D., F.R.S. ¢ Professor Scotr-E.uiot, F.L.S. Kelso—Rev. GEorGE GUNN, M.A., Stichill Manse, Kilbarchan—Rey. G. ALISON. Lincola—GeEorGE May Lowe, M.D., C.M. London—WILLIAM CARRUTHERS, F.R.S., F.L.S. : E. M. Homes, F.L.S., F.R.H.S. ‘3 Sir GrorGe Kine, M.D., F-.R.S. Melrose—W. B. Boyn, of Faldonside. Otago, New Zealand—Professor JAMES Gow Buack, D.Sc., University. Perth—Sir Ropert Puivar, F.R.S.E. Philadelphia, U.S.A,—Professor Joun M. MACFARLANE, D.Sce., F.R.S.E. Saharumpore, India—J. ¥. Dutuir, B.A., F.L.S. St. Andrews —Professor M‘Intosu, M.D., LL.D., F.R.SS. L. & B. = Rospert A. Ropertson, M.A., B.Se. by Dr. J. H. Witson. Toronto, Ontario—W. R. Rippe i, B.Se., B.A. fg ” Professor Ramsey Wriaut, M.A., B.Se. Wellington, New Zealand—Sir James Hecror, M.D., K.C.M.G., F.R.SS. L. & E. Wolverhampton—JOUN FRAsER, M.A., M.D. BOTANICAL SOCIETY OF EDINBURGH XXXl1 The TREASURER submitted the following Statement of Accounts for the Session 189S— Report thereon :— INCOME. Annual Subscriptions, 1898-99; 57 a and 1 at 10s. Do., 1897-98, Transactions. etc., sold : Subscriptions to Illustration Fund . Interest on Deposits in Bank 2 at 15s. . EXPENDITURE. Printing Transactions, £36 ; Billets, etc., £6, 10s. . Rooms for Meetings, Tea, and Hire of Screens Stationery, Postages, Carriages, etc. Fire Insurance on Books, ete. Expenditure Balance of Income STATE OF FUNDs. Amount of Funds at close of Session 1897-98, subject to Expense of Printing Transactions : : Deduct—Cost of Printing Transactions for Session 1897-98 Add—Increase during Session 1898-99, as above Amount of Funds at close of Session 1898-99 Being:—Sum in Current Account with > Union Bank of Scotland Ltd. . Bes 0 Sum in Deposit Receipt with do. 100 0 0 Due by Treasurer : ; : 8 5 § 99, with the Auditor’s FAS nO LAD 2 oto 'O aoe G6 Dev ame’ £56 14 11 £42 10 O 6 11 11 Se aes O* 5°20 £54 16 7 Lots .4: S56 14514 £133" 2 10 Ay-13), 6 See Oy 4: 118. 4 Shin’ 2S SHSAe Ss Note.—Subscriptions in arrear, 1898-99, £1, 10s. XXXii TRANSACTIONS AND PROCEEDINGS OF THE On the motion of the Rev. Dr. DAvip Paut, M.A., seconded by Dr. Wittiam Craic, the Statement of Accounts was adopted, and the Treasurer thanked for his services. The retiring President, Dr. WM. Watson, delivered the Presidential address. The Chair was taken by the Rey. Dr. Davin Paut, M.A., the President elect. Specimens of lewrotus Serotinus were exhibited by the PRESIDENT. The following paper was read :— Notes on Tree Measurements at San Jorgé, Uruguay. Part ii. By C. E. Hall, Esq. Communicated by Dr. David Christison. MEETING OF THE Society, December 14, 1899. Rev. Dr. Davin Paut, M.A., President, in the Chair. Mr. RurHerrorp HIiLi exhibited specimens illustrating the preparation of Betulin and Pyrobetulin from Birch Bark, and some of the applications of these substances in the Arts, and to Medicine. . Mr. F. C. Crawrorp exhibited specimens of Carex limosa from Arran, constituting a first record for this plant from’ that island. The PRESIDENT exhibited specimens of Carex limosa from toxburghshire. Mr. ALEXANDER SOMERVILLE exhibited specimens of Carex limosa and C. Megalanica, illustrating the character- istic differences which exist between the species. Mr. ALEXANDER SOMERVILLE exhibited, and afterwards presented to the Society, a Chart enumerating the Watsonian vice-Counties, and giving details of their boundaries, — ea BOTANICAL SOCIETY OF EDINBURGH XXXlll The PrEsIDENT exhibited a number of species of (easter, including G. fimbriatus, G. Bryanthii, G. coliformis, ete. The following paper was read :— Supplementary Notes on Andromeda polifolia, being an account of Observations made during 1899. By Symington Grieve, Esq. MEETING OF THE Society, January 11, 1900. Rey. Dr. Davin Pau, M.A., President, in the Chair. Mr. R. Linpsay exhibited a plant of Andromeda hypnovdes. Mr. F. C. CrawrorD exhibited a complete series of dried specimens of the plants collected during the Excursion of the Scottish Alpine Botanical Club to Kirkby Lonsdale, in 1899. The following papers were read :— I. The Report of the Excursion of the Scottish Alpine Botanical Club to Kirkby Lonsdale, in 1899. By Dr. William Craig, F.R.S.E. Il. Notes on the Lenticels of Solanum Duleamara. By James A. Terras, B.Sc. MEETING OF THE Socrety, February 9, 1900. Rev. Dr. Davin Paut, M.A., President, in the Chair. Miss SPRAGUE exhibited a number of herbarium speci- mens of Norwegian plants. XXXIV TRANSACTIONS AND PROCEEDINGS OF THE The following papers were read :— I. An Obituary Notice of the Rev. George Gunn, M.A., late of Stichill. By the President. II. Notes on a Tour in the Dovrefjeld, Norway. By John Montgomery Bell, W.S. The last paper was illustrated by a large herbarium of plants collected by the Author in Norway. MEETING OF THE SociETy, March 8, 1900. Rev. Dr. Davip Patt, M.A., President, in the Chair. ALEXANDER CowAN, Esq., of Woodslee, Penicuik, was elected a Resident Fellow of the Society. Mr. RurHErFORD HiLt exhibited specimens of Caffeine, and some of its salts, together with the Teas from which it is extracted. Dr. R. Stewart MacDouGAtt exhibited— I. A stem of a Poplar attacked by Cossus ligniperda, and showing the Cossus galleries occupied by rhizomorphs of Agaricus melleus, II. Specimens of the Galls of Retinia resinella. Mr. ALEXANDER SOMERVILLE exhibited a mounted speci- — men of the Goat Moth. The following paper was read :— Contributions to the Flora of Spitzbergen, especially of Red Fiord, from the Collections of W. 5S. Bruce, F.R.S.G.S. By Robert Turnbull, M.A., B.Sc. The paper was illustrated by dried specimens of the plants deserfbed, and by lantern slides of the vegetation, prepared by W. S. Bruce, F.RS.G.5. ) el BOTANICAL SOCIETY OF EDINBURGH XXXV MEETING OF THE Society, April 12, 1900. Dr. T. B. Spracus, in the Chair. Mr. F. C. Crawrorp exhibited a series of microphoto- graphs, illustrating the structure of the stem in British Boraginee and Caries. Mr. W. G. Buack exhibited an oil painting and a number of photographs of a clump of trees blown down by the gales of November and December 1886. Dr. R. Stewart MacDovucatu, M.A., exhibited a case of specimens illustrating Mimicry among European Lepidop- tera. Mr. R. Linpsay exhibited flowering pot plants of Primula denticulata, P. marginata, P. floribunda, P. verti- cillata, P. frondosa, and a blue form of P. vulgaris. The following papers were read :-— I. Artemisia stelleriana, Boss., in Scotland. By G. Claridge Druce, M.A., F.L.S. Communicated by Dr. R. Stewart MacDougall, M.A. II. The Functions of the Climbing Roots of Ivy. By Commander F. M. Norman, R.N. III. On a Deciduous Cedrus Atlantica. By Commander F. M. Norman, R.N. ITV. On an Elder growing on an Apple. By Com- mander F. M. Norman, RN. MEETING OF THE Society, May 10, 1900. Rev. Dr. Davin Pau, M.A., President, in the Chair. The following papers were read :— I. Variations in Lycopodium clavatum. By R. A. Robertson, M.A., B.Sc. II. Mehnert’s Principles of “Time Displacements ” applied to the development of the Sporophyte. By k. A. Robertson, M.A., B.Se. XXXV1 TRANSACTIONS AND PROCEEDINGS MEETING OF THE Society, June 14, 1900. Rev. Dr. Davin Paut, M.A., President, in the Chair. Mr. R. A. Ropertson, M.A., B.Sc., exhibited specimens of Lucalyptus ficifolia in fruit. Miss R. Orrock exhibited specimens of Aucalyptus sp. in flower. The PresmDENT exhibited flowers of Geranium sylvaticum, var. album, sent by Dr. Stuart, of Chirnside. The following papers were read :-— I. A Preliminary Note on some Witches’ Brooms. By R. A. Robertson, M.A., B.Se. II. Notes on the Germination of the Winter Buds of Hydrocharis Morsus-Ranw. By James A. Terras, B.Sc. MEETING OF THE Society, July 12, 1900. Rev. Dr. Davip Paut, M.A., President, in the Chair. Mr. R. A. Ropertson, M.A., B.Se., exhibited fresh speci-— mens of Hucalyptus citriodora. Mr. A. Murray exhibited a specimen of JMJelanogaster ambiguus, found by him in the garden of the Royal Blind Asylum, Craigmillar Park. The following paper was read :— A Preliminary Note on the Flower of the Potentillez. sy R. A. Robertson, M.A., B.Se. ii TRANSACTIONS AND PROCEEDINGS OF THE BOTANICAL SOCIETY OF EDINBURGH. SESSION LXI. ADDRESS DELIVERED AT THE OPENING OF THE SESSION BY Professor A. P. AITKEN, M.A., D.Sc, President of the Society. —12th November 1896. THE NITROGENOUS FOOD OF PLANTS. In the year 1674 a very remarkable discovery was made by John Mayow, viz. that the air, which from all time had been regarded as an elementary substance, was really a mixture of at least two gases—one of them was a gas which enabled things to burn, and the other was one that did not. Moreover, he found that the gas which enabled things to burn, or which “supported combustion,” as it is commonly expressed, was also the gas that enabled animals to breathe or that supported respiration, and that the other did not. He carried his researches even further, and found that this active gas, which he called the “nitrous spirit of the atmosphere,” took part in the making of acids, though it was not sour itself, and also that it was contained in large quantity in nitre or saltpetre. Strange to say that discovery seemed to create no interest at the time, the story of it was told to listless ears and it fell into oblivion. Exactly one hundred years later (1774) that same nitrous spirit of the air was discovered by Priestley, who called it “dephlogisticated air,’ and it was thereafter described by Lavoisier, who called it “oxygen” or the acid maker. The other constituent had been discovered by Rutherford in the Botanic Garden of Edinburgh in 1742, and shown to be a gas that animals could not live in, and he called it “mephitic air.” I do not know how it was that Professor Rutherford was led to make the experiment that resulted in this discovery, but it was a very satisfactory experiment, TRANS, BOT. SOC, EDIN. VOL. XXI. B 2 TRANSACTIONS AND PROCEEDINGS OF THE [Suss, LXI. made with very simple apparatus, viz. a bell jar, a basin and some lime-water, and a few mice. He put the lime- water in the basin and inverted over it the bell jar. Under the bell jar he slipped a mouse and watched its behaviour. When it began to show signs of distress he pulled it out by means of a string tied to its tail and slipped in another in its place. The second mouse showed signs of distress much sooner than its predecessor, and another mouse was substituted, who succumbed in a still shorter time. On continuing the experiment it was found that the air under the bell jar had grown smaller in bulk, and that it was of a kind that a mouse could not endure with comfort for a moment. This was the second great constituent of the atmosphere, to which Lavoisier in after years gave the name of Azote, to signify that it was a gas in which animals could not live. For the same reason the Germans call it stickstoff or choking stuff, while we in this country call it nitrogen, which means the nitre maker, for it is found in nitre as a very characteristic constituent along with oxygen— the nitrous spirit of Mayow. Later researches showed that this gas, nitrogen, in which an animal could not breathe and a candle could not burn, occupied about four-fifths of the entire atmosphere, the remaining fifth being oxygen. The properties of nitrogen were studied by many chemists, but it was found to be a very uninteresting subject. It formed very few compounds, and its disinclination to unite with other elements earned for it the name of the chemical bachelor. It was found to be an idle, inert kind of a loafer, good for nothing but to get in the road of the molecules of oxygen and interfere with their oxidising work, for before a molecule of oxygen could get at anything to burn it, it must needs knock four molecules of nitrogen out of its way and heat them up into the bargain, thereby greatly diminishing the energy of combustion all over the globe. It was found, however, that when nitrogen did get into combination with other elements it could form very powerful and important substances such as ammonia, its compound with hydrogen, and nitrie acid, its compound with oxygen. Besides these two gases, there were found in the air others in small quantity but of immense importance, water ciate pee ce —a Nov. 1896. ] BOTANICAL SOCIETY OF EDINBURGH 3 vapour usually forming less than one but often more than two per cent. of the air, and carbonic acid present to the extent of about three or four parts in ten thousand. Still more elaborate analyses have shown that ammonia is in the air to the amount of one part per million, or less, and that traces of nitric acid are also sometimes to be found. The relation of these gases to plant life very soon began to be noticed, speculated about, and experimentally investigated. Priestley, the year before he discovered oxygen, had, with the watchful eye of genius, made a very interesting observation. He found that air which had been “depraved,” as he called it, by burning a lamp in it, or by Breathing in it, could be restored to its former purity by putting a growing plant in it and exposing it to the sunlight. The explanation of that curious circumstance did not come till a good while later. Indeed, it was not till the beginning of this century that botanists were assured that plants with green leaves took their carbon from the carbonic acid of the air, and gave out a corresponding quantity of oxygen, and that one of the great functions of plant life was the restoration to the atmosphere of the oxygen of which it had been bereft in the universal processes of respiration and combustion. Familiar as we are with that fact at the present day, it never ceases, and never can cease, to be a subject of great interest and continual wonder that the green vegetation that clothes the globe, from the tiniest alga to the greatest forest tree, derives the half of the dry matter of which it is composed, viz. its carbon, from the carbonic acid of the air, although that gas is present in the atmosphere only to the limited extent above mentioned. It was found that this formative process, which is called assimilation, went on only in daylight, and most vigorously in sunshine. During the night or in the dark, plants were found to give out only carbonic acid, and further investigation showed that plants were constantly giving out carbonic acid both by night and by day in common with all other organised beings, whether vegetable or animal, and that act is known as respiration. Every living thing must breathe; it must take in oxygen to burn up its waste carbonaceous matter, and give it out as carbonic acid. 4 TRANSACTIONS AND PROCEEDINGS OF THE [Szss. uxt. The quantity of oxygen that is used up, and the corre- sponding quantity of carbonic acid that is given out by such a torpid creature as a plant during the night, is very small, and is more than compensated by the reverse process which takes place during half an hour’s sunshine in the morning. Although it is about a hundred years since the main fact concerning the process of assimilation was known —what may be called the upshot of the process—we are yet very far from knowing how it is that plants take their carbon from carbonic acid gas and convert it into their own tissues. We can see the formation of starch in the chlorophyll.cells during sunshine, and its disappearance during darkness, but as yet we know nothing certain regarding the steps which lead up to the formation of starch. Whether the chlorophyll takes a formative part in the making of starch, or whether it simply acts as a screen to allow only select rays of light to reach the laboratory where the carbonic acid is being decomposed, and whether this product is hypochlorin, as Pringsheim suggests, or formic aldehyde as some have supposed, we know nothing sure. The chemistry of the carbohydrates is a very intricate subject, and difficult of exploration, and only the rudiments of it are as yet known. If that is the case with the carbohydrates, it 18 so in a still more marked degree with the nitrogenous constituents of plants. The molecule of starch is simplicity itself compared with the molecule of albumen, which may be regarded as the finished article of the nitrogenous kind that is built up in the tissues of plants. It has been estimated that the molecule of albumen may consist of from 5000 to 5000 atoms. Such estimates are mere guesses, scarce worth considering, but they serve the purpose of impressing upon the mind the extreme complexity of some of the nitrogenous substances of which plants are composed, and the enormous difficulties which that complexity places in the way of their investigation. It is to the nitrogenous parts of plants, and especially the nitrogenous food of plants, that I wish to direct your attention for a short time; and I have been prompted to do so from the knowledge that there will be brought before Noy. 1886.] BOTANICAL SOCIETY OF EDINBURGH 5 the Society during the present session some interesting information on the recent advances of a practical kind that have been made in the growth of plants, arising out of our better acquaintance with the manner in which they obtain their nitrogenous nourishment. I have already referred to the fact that four-fifths of the atmosphere consists of free nitrogen gas. With such an enormous store of nitrogen around them it would seem, at first sight, that whatever difficulty plants might find in obtaining the other constituents of which they are composed they ought to experience no difficulty in obtaining an abundant supply of nitrogen. Practical experience, however, shows us very clearly that it is the constituent most difficult for them to obtain, as it is the most expensive for us to supply. The natural conclusion to arrive at from that consideration is that the nitrogen of the air must surely not be an available source of plant nourishment. Up to the present decade there was no dogma more firmly rooted in the minds of botanists than this, that plants could make no use of the free nitrogen of the air. Careful experiments made by Boussingault, who was a most accurate experimenter, and whose manifold experiments may be said to have laid the foundation of agricultural chemistry, seemed to prove that plants could not assimilate free atmospheric nitrogen. No excuse is needed to ask you to look for a minute into the details of one of his now classical experiments. Weight | Weight | Nitrogen of of in Seed. | Plant. | Seed. Duration| Number of Ex- of periment} Seeds. Nitrogen Gain or in Loss of Plant. | Nitrogen. Gin. Gm. Months. | Gm. Gin. Gm Bean, nain 2 1 | °780| 1°87 | -0349 | °0340 | — "0009 | ae tat 2 1 | -792| 2°35 | 0354 | 0360 | +-0006 | i pe 2h 1 "665 | 2°80 | 0298 | 0277. - °0021 3, AMES, 3 1 +530 °89 | 0210 | 0189 | — 0021 es 5. 3 | 1 | °-618| 1°13 | 0245 | 0226 | — °0019 Lupine, white 14 | 2 *825 | 1°82 | ‘0480 | 0483 | +°0003 mi a's 2 6 | 2:202| 6°73 | 1282 | "1246 | — -0036 os iy 12 | 2 “600 | 1°95 | 70349 | 0339 | —:0010 23 nee ts | 1 | -343| 1-05 | -0200 | -0204 +0004 | 93 - 14 2 | -686| 1-53 | -0399 | -0397 | —-0002 | Oat . 2 10 | °377| ‘54 | -0078 | 0067 | —-0011 | eS : moles 4 139 | 44 | 0031 , 0030 - “0001 | riss A 3h REMnE GOS IG.ce Nh Sanda Mae : 5, aS Manure ve | 10 026 |) a 0013 | “0013 6000 | | 6 TRANSACTIONS AND PROCEEDINGS OF THE [Suss. LXI. He grew plants of various kinds in an air-tight case in soils that were composed of sand, to which he added the ashes of plants to serve as manure, but which contained no nitrogen in any form of combination. Tubes were inserted in the case through which he could water the plants with pure distilled water, and others through which air was led in after passing through sulphuric acid, to deprive it of any ammonia, and over bicarbonate of soda, to deprive it of any nitric acid. Thus no nitrogen was allowed to reach the plants but that of the free nitrogen of the air. He weighed the seeds at the beginning, and the whole plants at the end of each experiment, and you will see from the table that the whole plant was usually only two or three times the weight of the seed itself. He estimated the nitrogen in the seeds from an analysis made of a number of others of the same kind, and, at the end, he determined the total amount of nitrogen in the plant and in the small quantity of soil it grew in. You will see that there was usually a loss of nitrogen, and in one or two cases a trifling gain. He varied his experiments, afterwards, by giving the plant a small ascertained amount of nitrogenous manure, but the results were similar, and he felt entitled to conclude from all his experiments that plants could not assimilate the free nitrogen of the air. Coming from such a weighty authority, this view obtained general acceptance. About the same time (1850) M. Georges Ville, Director of the Ag. Exper. Station at Joinville, Paris, was engaged in a series of experiments with a similar object in view. He had no confidence in Boussingault’s experiments on account of the unnatural conditions under which he attempted to grow his plants, and he despised a crop which weighed only two or three times the weight of the seed. He also grew his plants within an air-tight case, and had complete control of the water and air supplied to them, but he gave them some nitrogenous manure, and plenty of soil and air. The result was that his plants grew to normal size, 50 or 100 times the weight of the seed they sprang from, and he found that they had assimilated free nitrogen, sometimes in a very marked degree. He grew cereals, leguminous plants, and cruciferous plants, and found that ee it Nov. 1896. ] BOTANICAL SOCIETY OF EDINBURGH 7 in every case there was an assimilation of atmospheric nitrogen, but mostly in the case of leguminous plants. He published his researches, but the results were received with incredulity. They differed so totally from those of Boussingault, a distinguished member of the French Academy, that scientific men felt sure he had made some mistake, and the bitter things said against poor Georges Ville’s researches rendered his life miserable. He never lost confidence, however, in the accuracy of his work, and eventually he threw down a challenge to the French Academy to appoint a committee of experts to superintend one of his experiments. The Academy took it up, and a committee of very eminent men were appointed—Dumas, Regnault, Payen, Decaisne, Peligot, and Chevreul. They superintended the experiments for several months; one important part of their supervision was to see that no nitrogenous matter was supplied to the plants in the water they were watered with. Accordingly, every time the plants were watered the residue of the water was put into a large vessel for after investigation. At the close of the experiment this water was analysed, and it was found to contain some ammonia. This staggered Ville very much, and on inquiring into the matter he found that a few days before the water was tested some of the pupils in the Museum of Natural History, where the experiment was conducted, had been making ammonia gas, which, being a penetrating gas, had very probably reached the water and been absorbed by it. The committee were of course constrained to report that they were not satisfied that the plants had not received some ammonia from the water used in watering them. But the Academy voted Ville 2000 francs to defray the expenses of the investigation, and other 2000 to enable him to go on with it. Thereafter two English experimenters entered the field, viz. Messrs. Lawes and Gilbert, at Rothamsted. They resolved to repeat Boussingault’s experiments, but with the adoption of a number of elaborate precautions, so as to prevent any possible chance of error. The result of their investigation was to confirm the accuracy of Boussingault’s conclusion, and that practically disposed of the question for 8 TRANSACTIONS AND PROCEEDINGS OF THE [Szss. LXI. the time, but it did not silence Ville. He published a new edition of his researches in 1867. After having repeated many of his former experiments, and found them accurate, he was able, from his added experience, to see how Boussingault’s method could not end in anything but failure. The plants, he maintained, could never be anything but sickly, misthriven objects under the conditions of growth he imposed on them, and he pointed out that on account of these conditions the puny plants were not allowed to arrive at that stage of development when it was possible for them to utilise the free nitrogen of the air. In his experiments he gave the plants sufficient soil to enable their roots to grow, and he supplied them with a certain small amount of nitrate of soda, just enough to tide them over their childhood, so to speak, but not enough to pamper them and make them lazy in the vigour of their youth. He held the view that plants, like other beings of a higher type, when they found within their reach two sources of nourishment, took the one that was easiest got at; so that if a plant found nitrogenous food among its roots it absorbed that, and did not exercise its power of taking, with more difficulty, its nitrogen from the air. By careful experiment he discovered how much nitrate of soda was needed to give his plants a good start, and he stopped there, and let them find the rest of their nitrogenous food in the free nitrogen of the air he supplied to them. So far as I can discover, no particular attention was given to Ville’s further publication, and almost nobody had any confidence in his conclusions. Happening to be in Paris just twenty years ago, I paid a visit to the Experiment Station at Joinville, and knowing it was a public institu- tion, I gave no notice of my coming. Unfortunately I did not get access to the grounds, as M. Ville was from home, but the inquiries I made regarding the work carried on there among some leading scientists in Paris were usually answered by that characteristic shrug of the shoulders with which our neighbours across the Channel are able to convey a wonderful amount of tacit information. It was quite evident that he was not regarded by the Parisian scientists as one of their set. Noy. 1896.] | BOTANICAL SOCIETY OF EDINBURGH 9 Seeing that the free nitrogen of the air was regarded by the highest authorities to be unavailable for plant nutrition, it became necessary to cast about and find What stores of combined nitrogen were available in the world. I have already referred to the ammonia, which, as carbonate of ammonia, is a constant though minute con- stituent of the atmosphere. Its amount has been often estimated, and the estimates show extraordinary variations, from 1 part in twenty millions to as much as 34 parts in one million; depending on the locality where the sample of air was taken. Over the land it is more than over the sea; and it is greatest near towns where coals are being burned, and in places where organic matter is decaying. According to Angus Smith the ammonia in its rain-water over England is just about 1 part per million; in Scotland it is only half as much. In towns in England it is 5 parts on an average; in Scottish towns it is somewhat less, but in Glasgow it is 9 parts per million. It is very soluble in water, and is washed out of the air by rain. After thunderstorms there is also found nitric and nitrous acids, or their salts, in the air, and these too are washed down by rain. Rain-gauges at various observatories in Europe, notably at Rothamsted in England, have been in use for many years, to determine not only the quantity but also the quality of the rain that falls throughout the year; and the total combined nitrogen brought to the earth by them has been found to be some- where between 4 and 10 lbs. per acre. That is a very welcome addition to the nitrogenous food of the soil; but it forms only about one-tenth of what is removed by a moderate cereal crop, and is insufficient to recoup the soil for the loss which it is constantly incurring by drainage. Always there is nitrogen in some form of combination flowing down the rivers to the sea, and the store of it on the land is being diminished. It forms an important manurial constituent for the nourishment of seaweeds, and these again are the food of fishes, many of which are brought back to the land to be consumed as food; but any such restoration goes but a very little way in making good the drain of nitrogen in some form of combination which the land is constantly suffering. Still more serious is the loss of combined nitrogen from 10 TRANSACTIONS AND PROCEEDINGS OF THE [Szss. Lx1. the decomposition of nitrogenous compounds in a number of ways. When, in the ordinary course of nature, living things, be they animal or vegetable, fall into decay, the nitrogenous compounds they contain do not all escape into the air as ammonia, as was at one time believed. Liebig, in his famous book on “ Organic Chemistry in its Applica- tion to Agriculture and Physiology,” published in the middle of this century, taught that from carbonic acid gas, water, and ammonia, came the food of the world, and back to carbonic acid, water, and ammonia it all returned, either directly in its decay, or indirectly in the life and death of the animals whose frames it temporarily served to support. It was a beautiful generalisation, this cycle of change through which all organic life was held to pass; but careful investigation of the products of organic decay has shown that much of the albumen, and other nitro- genous matter contained in living organisms, is decomposed during their life, as well as at their death, into something even simpler than ammonia, viz. into the element nitrogen itself. The proportion of the albuminoid matter reduced in this way may be very considerable, and may even amount to one-fourth of the whole of the nitrogen of the substance if conditions are favourable. Even when the nitrogenous organic matter has had its nitrogen converted into the inorganic form of nitrates, or nitrites, it is not safe; for apart altogether from the extreme ease with which these salts are washed out of the soil and into the water-courses by rain, they are, while resident in the soil, liable to be reduced in the presence of much organic matter, especially if cut off from a circulation of air; and that reduction, stopping short of ammonia, liberates their nitrogen in the uncombined state. It has been observed that these instances of reduction are greatly hastened, if they are not entirely brought about, through the instrumentality of micro-organisms in the soil, or in any place where organic matter is accumulated. But also in the presence of air there are decompositions taking place in decaying organic matter, whereby oxidised and unoxidised products re-act upon each other and liberate the whole of their nitrogen as free nitrogen gas. Noy. 1896.] | BOTANICAL SOCIETY OF EDINBURGH 11 It would take me too far to enter into any detail regard- ing chemical processes of that kind, and it is the less necessary because, although they are known to occur, I have no idea of the extent to which they are operating, and I cannot estimate their importance. As when organic substances are being consumed by the slow processes of putrefaction and decay, so also when they are being burned a considerable part of the nitrogen is set free as such. The burning of wood and of coal are opera- tions in which a very appreciable amount of uncombined nitrogen is set free. It may be said of coal that its com- bustion is a gain rather than a loss to the available nitrogen of the world, because far more of the nitrogen it contains is set free as ammonia than as nitrogen gas. No doubt that is so, but the nitrogen contained in the coal measures must have been got from the atmosphere at the time when the plants that made the coal were growing, and we can regard the nitrogenous matter locked up in them only as part of the funded capital of the combined nitrogen of the world, and any process of combustion which sets the com- bined nitrogen free is an expenditure of that capital, and it is evident that if the process of spending goes on long enough, there will by and by be no capital of combined nitrogen to draw upon. Besides the sources of loss which I have indicated as going on in what may be called dead organic matters, there are others which are known to be going on in the bodies of living animals,—fermentations in which the nitrogen contained in the albuminoid matter of their food is to some extent liberated in the uncombined form. It will be seen that the circumstances in which combined nitrogen becomes free are very various, and as we do not know them all, but probably only a few of them, we are forced to conclude that, unless there are some means whereby free nitrogen is brought again into combination, and unless these means are not only active but abundant, we must be hastening on to a time when life in any form upon the globe must become extinct for want of nourish- ment. A survey of the history of the globe shows us, however, that life is on the increase, and that organic matter is 12 TRANSACTIONS AND PROCEEDINGS OF THE _ [Szss. x1. constantly accumulating. We have only to look at the rocks of which the earth’s crust is composed to be assured that at one time this planet was a molten ball on which there was no organic matter, and now it is clad in a dress of living green, and teeming everywhere with life. That vegetable and animal life should have increased so abundantly, requires that either there must at one time have been an immense store of ammonia in the atmosphere, which has gone on constantly diminishing, or there must have been, and there must be now, some process going on on a large scale whereby ammonia is being formed out of the free nitrogen of the air. We have no reason to suppose, however, that there ever was a larger store of ammonia in the air than there is at present. The certainty is rather that at one time, viz., when the earth was at a white heat, there was no ammonia in our atmosphere at all. A red heat suffices to decompose it into its two component gases, nitrogen and hydrogen—one volume of the former and three of the latter,—and these on cooling do not again unite. It is hard to see how ammonia, if it did exist in the atmosphere at that time, could escape decomposition, and the fact that in the atmosphere there is scarcely a trace of hydrogen, and, moreover, that what little there is can be easily accounted for by volcanic action, we naturally come to the conclusion that there was no ammonia in the original atmosphere of the earth. We have therefore good reason to believe that the total amount of ammonia in the atmosphere is now not less, but probably more than it ever has been. Seeing that there are so many ways in which combined nitrogen may be set free, and that the quantity of com- bined nitrogen on the globe is on the increase, there must be some process of a widespread general kind going on around us whereby the free nitrogen of the air is being brought into combination. Despite the dictum of weighty chemical authorities that plants could not convert free into combined nitrogen, there remained many who believed that they must possess that power; for if it were not possessed by plants, there seemed to be no other direction in which to account for the ordinary conditions of organic life on the globe. Noy. 1896.] BOTANICAL SOCIETY OF EDINBURGH 13 Moreover, there were some curious facts known to agriculturists that could scarcely be explained in any other way. It was well known, from the time of the Romans, that when leguminous plants were grown on land under rotational cultivation, an abundant crop of that kind was followed the next season by a good cereal crop. They were of opinion that the leguminous crop enriched the soil, Farmers in this country, too, have known for ages that a good crop of wheat was certain if a good crop of clover had preceded it. Now chemical analysis shows us that the clover crop is very rich in nitrogenous matter; and if we assume that this nitrogenous matter comes to the crop from the soil, it stands to reason that the removal of a clover crop should leave the soil poorer in nitrogenous matter than before. Such, however, is not the case. Chemical analysis shows that the soil is richer in nitrogenous matter after the clover crop has been carried away; so that either the roots of the clover left in the ground must have got their nitrogen from deep down in the ground, or it must have come to the plant from the air and have been stored up to some extent in the roots. Another common observation was that when a crop of maslum was grown, which is a mixture of beans and oats, or when tares and oats are grown together, the oat plants are stronger and taller than those on any part of the field where the oats have grown separately. So also it is commonly observed that in pastures the places where clover is most abundant are the places where the grasses are growing greenest. A very striking example of the power of leguminous plants to enrich the soil in nitrogen was furnished by Mr. Schultz, a farmer who owned the farm of Lupitz,in Altmark, N. Germany. The soil was little better than sand when he came into possession of it, and he could not afford to buy nitrogenous manures to bury in it, neither did he feed cattle to provide farmyard manure for it. He adopted the system of green manuring. He grew leguminous crops, chiefly lupines, and ploughed them in, and he manured his land with potash and phosphates, following Liebig’s 14 TRANSACTIONS AND PROCEEDINGS OF THE — [Szss. uxt. recommendations, and he also limed it, but he put on no nitrogenous matter. The result was that his land grew more and more fertile. He used to plough in a// his leguminous crop; by and by he reaped it, but still the fertility of the land increased. At first he followed his green manuring with a crop of rye, for the land was too poor to grow other cereals, but by and by he found he could grow oats and barley, and, in short, after a period of twenty years, he had converted a sandy waste into a rich, fertile soil containing abundance of nitrogenous matter. He declared that the nitrogen in his soil came from the air, and that the leguminous plants had brought it. He called them nitrogen collectors, and the cereal crops he called nitrogen consumers. This remarkable experiment soon gained notoriety, and farmers and scientists came annually in numbers to see it; and the impression left on their minds, when they com- pared this fertile farm with the barren, sandy land adjacent to it, was that leguminous plants at least must surely have the faculty of making use of the free nitrogen of the air. It had the effect of causing a number of the scientists who had charge of agricultural experiment stations to institute experiments anew, to test again the old vexed question. The first of these to arrive at satisfactory conclusions were Professor Hellriegel and his coadjutor, Dr. Wilfarth. They began their experimental inquiry in 1883, and three years later, in 1886, Hellriegel communicated to the Agricultural Section of the German Naturalists, at their meeting in Berlin, the interesting information that he had succeeded in proving that the leguminosze were able to assimilate the free nitrogen of the air, and what added immensely to the interest of that fact was the curious way in which they did it. I am not aware that the subject of Hellriegel’s discovery has ever been formally brought before the notice of the Society, although most of the fellows present are doubtless well acquainted with it; but as it is what is called an epoch making discovery, I think a short description of it, even at this late date, would be welcome to some of you, wa Noy. 1896 ] | BOTANICAL SOCIETY OF EDINBURGH 15 and an occasion like this is an appropriate one for the purpose. Time will not permit me to do more than trace its salient features in brief outline. The gist of Hellriegel’s discovery is this,—he found that leguminous plants of the sub-order Papilionacez were able to make their albuminoid matter by assimilating the free nitrogen of the air, and that that power was associated in some way with the growth of warty tubercles on the roots of the plants, and that these tubercles contained peculiar cells called bacteroids, due to the agency of bacteria which entered the roots of the plant from the soil. I shall explain how he came to the full possession of that knowledge immediately, but in the first place I would like to refer shortly to the tubercles or nodules themselves. Hellriegel did not discover the nodules. They have been known for a long time. The first mention of them that I am aware of was made by the famous Italian anatomist Malpighi, who described them in the year 1660. He thought they were galls, but he was surprised to find that they never contained eggs or larve. Coming to recent times, Treviranus describes them in a paper communicated to the Botanische Zeitung in 1853, but the first careful description of them was made by Woronin in 1866. He studied those found on the roots of Alnus glutinosa and Lupinus mutabilis. He described them as consisting of two distinct kinds of parenchymatous tissue, an inner and an outer, separated by a layer of vascular bundles proceeding from the vascular bundles of the root of which they were lateral excrescences. He noticed that the outermost cell of the inner parenchyma multiplied by division, and that the older cells contained a slimy mass of plasma, full of tiny little bacteria-looking bodies, which, when put into water, moved about just as bacteria do, and he thought that they were the cause of the nodules. Erikssen, in 1874, published a paper accurately de- scribing the development of the nodules on the roots of the Faba vulgaris, and observed that the region where the bacteroids were rapidly multiplying by division was entered by the hyphz of a fungus, which appeared like a knotted thread ramified through the mass. 16 TRANSACTIONS AND PROCEEDINGS OF THE [Szss. uxt. Frank and Prillieux, in 1879, described them, and regarded them as due to the attack of a parasitic fungus. Schindler, at the same time, studied them, and came to the conclusion that the fungus was associated with the leguminous plant in a symbiotic manner; and Brunchorst, some years later (1885), described the nodules as store chambers, where the plant laid up a store of albuminoid matter which it utilised during ripening. This view was suggested before by De Fries (1877), who held that the nodules were absorbers of nitrogen, which the plant utilised for making its albumen. Schindler, in 1885, thought they were connected with the plant in a symbiotic manner, and that their function was to absorb nitrogenous organic matter from the soil. Ischirch thought that these nodules grew best on soils that were poor in nitrogenous matter, and that they not only stored up nitrogen for the use of the ripening plant, but that they also went back partly to the soil and enriched it in nitrogenous matters also. It was when observations and views of that kind were current that Hellriegel and Wilfarth published an account of their experiments. These experiments commenced, as I said, in 1883. He found that when he grew leguminous plants and gramineous plants, say peas and oats, in the same soil—a soil consisting of sand, to which nutritive solutions were added—that the oats grew and flourished in proportion to the quantity of nitrate of soda supplied in the manure. When the amount added was small, the growth was small; when the amount was doubled, the growth was doubled; when the amount was trebled, the growth was trebled; and so on, until sufficient was added to produce a full crop, when, of course, the further addition of nitrate produced an ever- diminishing increase. It was quite plain that the oats derived their nitrogenous food precisely from the nitrate of soda provided for them. The peas, on the other hand, erew in quite a capricious manner; showing that they were not dependent for their nitrogenous food supply on the nitrate of soda, or at least not on it alone. As a matter of fact, the pot which got least nitrate grew the largest plants. _— Noy. 1896.] | BOTANICAL SOCIETY OF EDINBURGH 17 He further noticed that when the plants were grown in a poor soil—poor as regards nitrogen—they all came up equally well at first, and made a healthy braird, but as soon as the supply of nourishment contained in the seed was used up, they began to grow pale and yellow, and the oats died down. ‘The peas, however, did not die down, but after a period of ill-health they began to regain their green colour, and thereafter their growth was rapid, and eventu- ally they attained to full development. He found that those plants that flourished best had most nodules on their roots, and those that were most backward had fewest. This proved that vigorous growth and the development of root nodules were related to each other in some way. To test whether the growth of the nodules was dependent on the attack of micro-organisms in the soil, he grew some peas and other leguminous plants in pots whose soil he had previously sterilised by heating, and he found that in such soils the peas succumbed just as the oats had done; there was no revival of colour and strength as before. When, to such a sterilised soil, he added a little of a fertile soil, in which peas grew on a few cubic centimetres of the watery extract of such a soil, the peas grew as before, and pro- duced nodules on their roots. When he planted his peas in a sterilised soil to which nitrogenous manure was added, the peas grew, but they did not produce any nodules on their roots. What was proved then by these experiments was, that leguminous plants could grow in a soil supplied with proper nitrogenous nourishment just as other plants could, but that they could also grow in soils containing very little nitrogenous matter if well supplied with other essential manurial ingredients, and that the plants contained far more nitrogenous matter than was contained in the soil; that this gain of nitrogen was dependent on the growth of nodules on the roots, and in proportion to their abundance; that the appearance of nodules was possible only in soils where a certain organism, or certain organisms, were present, and not otherwise; that the interference of these organisms enabled the plant to take up free nitrogen, either by its roots or by its leaves, from the air in the soil, or from the TRANS. BOT. SOC. EDIN. VOL, XXI. Cc 18 TRANSACTIONS AND PROCEEDINGS OF THE [Szss. Lxt. air above the soil, in some unknown manner; that in the nodules there was a supply of nitrogenous matter which disappeared as the plant grew older, and that some of the nitrogenous matter of the nodules, and the organisms along with it, found their way back to the soil, and caused it to become richer in nitrogenous compounds. This beautiful, interesting, and important discovery was, as I have said, first communicated by Professor Hellriegel and his coadjutor, Dr. Wilfarth, but there were a good many others engaged in the same inquiry, and whose experiments led to similar conclusions. Chief among these were Professor Prazmouski, Berthellot, Attwater, and Marshall Ward. The last of whom has shown, in a paper read before the Royal Society of London (1887), that the organism which attacks the roots of the leguminosz, causing the growth of nodules, is not a bacterium, but a fungus whose minute germs are all but universally distributed in the soil. The much debated question is now solved. The loss which is constantly going on over the world in the con- version of combined into free nitrogen is being constantly recouped by the conversion of free atmospheric nitrogen into combined nitrogen by at least one sub-order of plants that is found abundantly distributed all over the world. The question naturally arises, are the leguminous the only kind of plants possessing this faculty of nitrogen assimila- tion? It would add vastly to the wonder of the process if that were so, and it would invest this sub-order of plants with a fascinating and absorbing interest. It is not natural to suppose that this power should be limited to only one sub-order of plants, and it would seem that other orders of plants are now recognised as in active, though it may be feeble competition. There is, however, one important set of plants that has been found to possess the faculty in a marked degree, viz. unicellular alge, which, though among the most minute of plants, make up by their number what they lack in size. This very important discovery was made by Berthellot and André. They found that soils in which no visible plants were growing, and from which all combined atmospheric nitrogen was excluded, did become richer in nitrogen, whose only source can be the free nitrogen of the air; and a microscopic examination of such soils shows the Noy. 1896.] BOTANICAL SOCIETY OF EDINBURGH 19 presence of minute unicellular alge, which they found to be the active agents in that fixation. That being so, there is no end to the possibilities of nitrogen assimilation by plants, for these unicellular plants resemble the cells of which most plants are composed, and it may yet be found that all plants possess in some degree, however small, the power of assimilating free nitrogen by their leaves. In most cases such power of assimilation may be so small in comparison with the demands which the plants make upon the nitrogenous matter in the soil, as to entirely escape observation until some specially devised methods of detecting and determining it are provided. Before closing my remarks I would ask you to recall the results I have already referred to that were obtained by Georges Ville. He knew nothing about the nodules on the roots of the leguminous plants he grew, nor did he know what was the modus operandi by which the plants he worked with obtained their nitrogen, but he discovered the main fact, that they did assimilate free nitrogen, and that the power to do so was not confined to the papilionacee, but shared by plants of other orders. Moreover, he laid down quite accurately the conditions under which that assimila- tion took place. And as it is right that those who have been pioneers, and who have made important discoveries, should get full recognition, it is important to recall the fact that Ville’s discovery was made forty-five years ago, and that his experiments were not matters of doubt or hear- say, but experiments whose results are all carefully and accurately recorded. I have called this paper “The nitrogenous food of plants.” It might be expected that I should proceed to describe in detail the various forms in which nitrogenous matters are provided for plant food. Any such description would far exceed the bounds of time at my disposal and of the patience at yours. I need only say in a sentence that numerous as the forms of nitrogenous food are, they are convertible into one very soluble form—nitric acid—which is believed to be the form in which chiefly, if not solely, plants take up their nitrogenous nourishment from the soil. Moreover, it is known that there are processes going 20 TRANSACTIONS AND PROCEEDINGS OF THE [ Sess. Lx, on in the soil whereby nitrogenous matters are converted into nitric acid; and that these processes, ike most other chemical processes going on in the soil, are achieved through the instrumentality of living organisms. The characters of some of these organisms, their life history, the work in which they are engaged, and the means by which that work may be controlled in some measure, so as to serve specific ends, will, I understand, be demonstrated at an early meeting of the Society, and it is to form a kind of introduction to that practical aspect of the subject that I have asked you to listen to this short historical sketch. EXPERIMENTS WITH NITRAGIN. By WILLIAM SOMERVILLE, D.(&c., D.Se., Professor of Agriculture, Durham College of Science. (Read, Thursday, 14th January 1897.) Those who have been following the various developments of “the nitrogen question” during the past few years would be more or less prepared for the announcement that appeared in the “ Deutsche Landwirtschaftliche Presse,” on the 8th of April last, to the effect that the bacteria, which establish themselves on the roots of Papilionaceous plants, and enable them to utilise the free nitrogen of the air, were on sale as a commercial article by the firm of Meister Lucius & Briining’s successors at Hochst am Main. The work of many distinguished investigators during the past decade had established the fact that the Papilionaceous family of the Leguminosze could make use of the supplies of atmospheric nitrogen in a way that was impossible for other plants. This power, however, is not inherent in the plants themselves, but is due to colonies of bacteria, which find a habitation in the wart-like nodules that are normally present in abundance on their roots. Without these bacteria the plants in question are in no better a position than others, and although our clover, peas, vetches, etc., may usually be trusted to find in the soil a sufficient number of the particular bacteria that they consort with, still there is always the chance that ——————— —— a JAN. 1897. ] BOTANICAL SOCIETY OF EDINBURGH 21 these minute organisms may be absent, and that, in con- sequence, the vigorous development of the plants may be prevented. Professor Nobbe, of Tharandt, and Dr. Hiltner, devoted much attention to the subject, and proved, amongst other things, that each Papilionaceous plant has its own varietal, if not specific, organism, and that for full development it is necessary that the roots of a Papilionaceous crop should have access to the bacterium which is specially adapted to it. They therefore instituted a series of pure cultures of the various varieties of bacteria that inhabit the roots of our more important Papilionaceous plants, and having patented these cultures, they entrusted their manufacture to the well-known chemical firm above mentioned. This pure gelatinous culture is known as “ Nitragin,” and is sold at M. 2°75 per bottle, this quantity being sufficient to dress a morgen. It will thus be seen that for 4s. 6d. one can obtain as much Nitragin as will treat an acre, so that if it produces practically any good effects at all, its use can hardly fail to be profitable. To apply the Nitragin to the land or the crop one is recommended either to mix it with water and then to add the seed to the solution immediately before sowing, or to mix it with some soil and afterwards scatter the mixture over the field. Early in May I obtained a few bottles of Nitragin, and at once started some small experiments to test its practical value. Without going into the details of the arrangement and conduct of these experiments, | may say that I was eareful (a) to apply the same quantity of seed to compar- ative plots, (>) to see that the Nitragin was not exposed to light, and was liquified at a temperature of less than 100° F., and (c) that in the various cultural operations of covering the seed, weeding the plots, etc., the worker should never go from inoculated to uninoculated ground. Asa matter of fact the weeding was all done from planks, each plot being provided with a sufficient number, which were utilized as occasion required. EXPERIMENTS WITH PEAS. Each plot consisted of a row 24 feet long, an interval of 24 feet occurring between adjoining rows. Five 22 TRANSACTIONS AND PROCEEDINGS OF THE [Sess. x1. grammes of Nitragin were taken for each plot and mixed with half a pint of water, after which the seed (1 pint) was poured into the mixture and rendered thoroughly wet. Dry sand was next added to absorb the surplus moisture and facilitate the distribution of the seeds. The peas (“Dicksons’ First and Best”) were then sown in a drill and covered in the usual way. This experiment was carried out in duplicate. The following are the weights of produce in an air-dry condition :— | | CA SPlots: ‘1B Plots: Total eee ENR Seep Pe shit of Straw : Straw gees. Seed. and Seed and wea Masks. Husks. Husks. — | oz. 07. OZ. Oz. oz. Not Inoculated 3 30°15 37°50 44°50 40 00 155°75 Inoculated - Sl pOOE2D 38°75 45°50 42°50 16600 Gain by Inoculation 5°50 1°25 1°00 2°50 10°25 In both sets of plots the Nitragin has apparently increased the yield, the gain of total produce being 6°6 per cent. EXPERIMENTS WITH BROAD BEANS. This experiment was carried out in exactly the same way as the preceding one, except that here the rows were 2 ft. apart, and only two thirds of a pint of seed (“ Early Long Pod”) was employed. SA Plots: Bi Plots ots ots Total Straw Straw Weight of | Seed, Straw Seed. and Seed. and and "iin, ks 2 Husks. Husks. re OZ. 02. OZ. 07. 0z. Not Inoculated ‘ 38°50 59°50 | 45°75 58°75 202°50 Inoculated. e01) (8D 2b 54°50 34°75 5425 | 178°75 Loss by Inoculation 3°25 5°00 | 11°00 4°50 23°75 In this case the inoculation failed to increse the yield, and, as before, the “B” plots confirmed the “A”s. The total produce is 11:7 per cent. less when Nitragin was added than when it was withheld. cf Jan. 1897. ] BOTANICAL SOCIETY OF EDINBURGH 23 EXPERIMENTS WITH LUCERNE AND BroAD RED CLOVER. Here each plot measured 24 ft. by 9 ft.,a path 2} ft. wide being left between adjoining plots. Three ounces of seed were employed for each plot of lucerne, and 1} oz. for _each clover plot. In neither case were the plots duplicated. The produce was weighed green immediately after cutting, with the following result. Weight of | Weight of | Lucerne. Clover. lbs. lbs. | Not Inoculated . Z 105 159-5 | Inoculated. : - 102 155°0 Loss by Inoculation . 3 | 4°5 In neither case did the Nitragin benefit the plants, the uninoculated produce being heavier by 2°9 per cent. in the case of the lucerne, and 2°8 per cent. in the case of the clover, than that grown upon inoculated ground. It will thus be seen that only in the case of the peas did the application of Nitragin result in an increase in the yield, but in any case the variations in the weights of of produce are too small to make it possible to say definitely that the inoculating substance had affected growth either one way or another. These experiments were carried out in a garden attached to the College, in which it may be assumed that peas and beans have frequently been cultivated during recent years. As the soil will thus be well supplied with the bacteria that associate with the roots of these plants, it is not surprising that the application of a pure culture of these bacteria should have been inoperative. But as regards red clover and lucerne, it may safely be assumed that neither of these plants has ever been cultivated in the garden, and the probability is that not a single plant of lucerne ever grew in the garden or indeed in any fields in the neigh- bourhood. The conditions, therefore, were to be regarded as distinctly favourable for exhibiting the action of the specific bacteria of these plants, and yet they faild to produce any effect. 24 TRANSACTIONS AND PROCEEDINGS OF THE [Sgss. Lx. Our experiences in the North of England appear to have been much the same as those of the few other investigators who have tried Nitragin in a practical manner in two or three other parts of the country. Nor does a greater measure of success appear to have attended the use of the substance on the Continent. The manufacturers of Nitragin recently sent a communication to the press, in which they contended that the many cases of failure that had been brought to their notice were to be ascribed to lack of care on the part of investigators, who, it was asserted, had exposed the Nitragin to too much heat or light, or had allowed the bacteria to be conveyed from inoculated to uninoculated ground. Such an explanation carries no conviction to the mind of anyone who is acquainted with the inoculation of soil by bacteria. At a recent meeting of the Associated Chambers of Agriculture, held at Halle, Dr. Kiihn gave an account of the experiments with Nitragin which had been carried out during last season by himself, Menzel, and Falcke. All the more important leguminous crops were made use of in these investigations, with the result that in no case did Nitragin produce an increase that could be said to be beyond the range of experimental error admissible in field experiments. In some cases the uninoculated crop was considerably better than that which had been treated with Nitragin, and Kiihn finishes his paper by expressing the hope that improvements in the methods of manufacture or application may yet make Nitragin of service in agriculture and horticulture. There is no doubt that Nitragin will next season get a_ very careful and extended trial on the part of scientists and practical farmers, although it would have been more encouraging had the trials of the past season given more successful results. i Fes. 1897. | BOTANICAL SOCIETY OF EDINBURGH 25 THE BACTERIA OF THE SOIL, WITH SPECIAL REFERENCE To Som InocuLation. By R. Stewart MacDovuGaAL.t, M.A., BSc. (Read 11th February 1897.) Up till about twenty years ago the soil was looked upon as made up merely of so many bits of dead material—stone and lime, and clay, etc. Tillage was a mechanical opera- tion, and changes that followed it were explained purely on chemical and physical grounds. In these last years, however, it has come to be recognised that the soil teems with myriad minute forms of life—useful, and harmful, and neutral; in a word, for the tiller of the ground the problem is not solely chemical, but also biological. Many workers in soil bacteriology have given their attention to the exact numbers of germs present in the soil, and in different layers of it. It would weary the reader to give lists of the numbers which vary in a gramme {just over 15 grains) of earth, according to the circum- stances, from only a few up to some millions. Let me rather give the general principles determining their number as enunciated by Maggiora:'—(1) The number of bacterial germs, in otherwise resembling circumstances, is in forest soils less than in arable land, and in these less than in the soil of inhabited places. (2) In non-cultivated soils the number of bacteria changes with (a) the geological formation and the height above the sea; (+) with the imperviousness or the aeration of the soil, the germs being much less numerous in the former than in the latter; (c) with the nature of the soil,—sandy soil is less rich in bacteria than, say, humus soils. (3) In cultivated soils the number of germs increases with the culture activity and with the bringing of dung. Strongly dunged soils are much richer than poorly dunged or undunged. The greatest bacterial richness is at a depth of 8 to 20 inches; below this the number quickly decreases. This is true for both cultivated and non-cultivated soils. If I say that Kramer, as an average of three experi- lMaggiora, Journal de la Agricole du Brabant, 1888. 26 TRANSACTIONS AND PROCEEDINGS OF THE [Szss. 1x1. ments with the same soil, found in one gramme of earth— At a depth of about 8 inches . : . 650,000 germs, y Ray ne ; - 500,000 ,, pa ‘ - 276,000. ,; ie : . 36,000 ,, ase is . , 5,600 _,, om ; ‘ 700, e ; ‘ rf : , ; . ss = ; a APR, 1897, } BOTANICAL SOCIETY OF EDINBURGH vO under a stain, as eosin, will be found injected to a considerable distance. There is also a method of injection by means of the filter pump (Darwin’s Physiology of Plants, p. 87). But there are many specimens which do not lend themselves to injection by either of these methods. I find the following simple method extremely useful both for class purposes and for private work. The apparatus once set agoing requires little attention, and a large number of specimens for laboratory work may be injected in succession in a short time with a minimum amount of trouble. I submit a few sections of stems injection-stained by this method, to show the amount of penetration it is capable of giving.* The practical worker will, however, find it useful for all kinds of plant members. To the end of a large glass funnel a length of india- rubber tubing is securely wired. The funnel is fixed at a convenient height, and the lower end hangs free eight feet or more in length; at the lower end is fixed a compressor clip. The stem, air-dried (I show an Aspidium stem injected after lying in laboratory for years), preserved in spirit, or fresh (perhaps in many cases preferably the latter), has its end cut smooth and circular, and securely wired into the lower free end of the tube. In the case of delicate stems, it is preferable to lute with Canada balsam or asphalt to avoid crushing. A beaker is placed beneath to catch the escaping fluid. The funnel and tube are now filled with a weak aqueous solution of fuchsin, the compressor clip removed, and the stem left to itself for a few hours. At the end of that interval it will be found that a con- siderable quantity of the stain has passed through the conducting elements, staining them en route. One advantage of using the living stem is that the stain is pretty well confined to the conducting elements, and hence a good differentiation staining may afterwards be obtained. The compressor clip is again applied, and the stem removed and transferred to a duplicate tube containing a solution of weak picric acid. This washes out the stain held in the conducting elements by capillarity, and darkens the stained elements, and at the same time fixes the tissues. * Aspidum stem (air-dried) ; Cycas stem (fresh) ; Dracaena (spirit material). 56 TRANSACTIONS AND PROCEEDINGS OF THE [ Sess. LXI. When the picric acid comes through clear, the stem is ready for the next part of the process. It is removed, and, if intended for sectioning purposes, is cut up into small pieces and placed in alcohol of at least 90 per cent. strength. In this it is decolorised, and after a few days is in good condition for sectioning purposes. The liquified elements of the conducting system are stained a fine pink. A good contrast is obtained by ground staining with hematoxylin on the slide. If the stem be intended for dissection of vascular system, the picric injection may be omitted and the preparation allowed to lie for a time in weak picric acid, and then preserved in aleohol until required. Pyrus ARIA AND ITS VARIETIES IN ARRAN. By Rev. Davin LANDSBOROUGH. (Read 8th July 1897.) I know the island of Arran well, and it seemed to me strange that its Rare Pyrus should be confined to a small portion of the north. There are places in other parts of the island seemingly suitable for its growth. Might it not also be found in some of these? I determined to search Arran for it. I wished, further, to ascertain if it could not be had in additional varieties; and if the varieties were accidental, or resulted from discoverable causes. This led to several excursions. I mention the principal :— UNSUCCESSFUL EXCURSIONS, First—At the end of May, with one of my sons, I started from Brodick, in the centre of the east coast; went up Glen Rosa to the Garbh Allt (24 miles); ascended this stream; descended into Glen Jorsa; forded it; ascended the connecting stream to Loch Tana; thence to Loch Dubh; descended Glen Schaftigill; passed into Allt-na-h- Airidhe ; descended to Dougrie; thence to Shedog Inn.— Twelve hours afoot.—No success. Second Excursion—Next day we took, for four miles, the road to Brodick; at Glen Loig, turned up the Craigan, the most considerable glen running southward through the Jvty1897.] BOTANICAL SOCIETY OF EDINBURGH 57 centre of the island; examined it and its tributaries; crossed the highway between Lamlash and Lag at its saddle: ascended to Loch Urie; descended by the Knock- enkelly Glen to Whiting Bay; thence to Kildonan—134 hours.—No success, save finding a magnificent plant of the Guelder Rose (Viburnum Opulus) overhanging a waterfall in Craigan Glen. Third Excursion—With the Rev. Robert Drummond, Lothian Road, Edinburgh. From Lochranza, in the north of Arran, we passed along the hillside southward, visiting the Fairy Dell and the Great Rent, the latter about 950 feet above the sea, and nearly forty feet in depth (recognisable by a mountain ash growing at its entrance) ; descended at the Old Salt Pans; advanced to Lagan, famous for its fossil beds; ended at Corrie-——No success. Fourth, Fifth, and Sixth Excursions.—Visited North Glen Sannox ; ascended its greatest gorge to the east shoulder of the first of the high Sannox range (Suidhe Fhearghas) ; passed by it into South Glen Sannox. Visited the glens and gorges on the side of Glen Sannox, and also those above Corrie to Maol Donn —half-way to Brodick. Ascended the gorges on both sides of Glen Chalmadale. —No success. SUCCESSFUL EXCURSIONS. First Successful Excursion Having been unsuccessful in south, east, and west, both in the centre of the island and by the coast, I drew nearer the already-known habitats of the Rare Pyrus. Having landed by the Fairlie and Campbeltown steamer at Pirn Mill, six miles south of Lochranza, I ascended the Allt Gobhlach to the beautiful little waterfall (The Raven’s Nest), two or three hundred feet above sea-level. Above this the botanical feature of the stream is the abundance of the aspen (Populus tremula). This was a good omen, as a plant of it grows with the Rare Pyrus in the tributary at the head of Glen Catacol. From the Allt Gobhlach stream I passed by the south shoulder of Beinn Bharain to Loch Dubh. In it I found Lobelia Dortmanna and Utricularia vulgaris, both of which grow also in Loch Tana and in Loch-na-Davie (1182 feet above sea-level). 58 TRANSACTIONS AND PROCEEDINGS OF THE [Szss. Lxr. A Striking Peculiarity.—Loch Dubh is a quarter of a mile in length and is about twelve hundred feet above sea- level. It is situated on the shoulder of Beinn Bharain, and must receive a very copious supply of. water, yet in the map of the Ordnance Survey no outlet is assigned it. At the northern extremity there is the bed of a stream leading to Loch Tana, yet, though there had been con- siderable rain recently, in the upper portion there was no water, though there was abundant evidence that at times in it there is the rush of a torrent. The explanation must be that the basin and sides of the loch are so gravelly that in ordinary weather the water finds through them sufficient exit. I now passed to Loch Tana (the Long Loch) and thence directed my course eastward. Mr. Smith, Monkredding, Kilwinning, in a remarkable paper, entitled “New View of the Arran Granite Mountains,” read March 1895 to the Glasgow Geological Society, and since printed, writes: “The Allt-an-Champ (the Camp Burn) gets its name from an old practice of the natives to camp here with their cattle during summer, and remains (traces) of their huts are still to be seen. It presents us at one part with a little glen cut in the solid rock to a depth of perhaps twenty feet. Growing out of a joint of the granite and overhanging the glen is a much-branched specimen of Pyrus aria, rare in this country. This is one of the few trees in the granitic area, and has not escaped the notice of the natives, who have a tradition that ‘ once upon a time a strange bird brought a seed and planted it here, and out of the seed grew this tree.” The Allt-an- Champ is a western tributary of the Iorsa and joins it 2% miles south of Loch-na-Davie. Guided by Mr. Smith’s interesting statement, and with the hope that the plant he mentions might not be a solitary example, I struck this stream half-way up and followed it up and down. I was successful, as I found several of the rare tree. I now pushed on by Loch-na-Davie to Corrie-—Eleven hours. Second Successful Kxcursion—When visiting, on former occasions, the head of Glen Catacol at its eastern division, where the Rare Pyrus has long been known to grow, I had noticed the steep gorge here ascending from its left Sbstielttienetiteie ec esate i a ee ee er Juty 1897.] | BOTANICAL SOCIETY OF EDINBURGH 59 side, and thought it also a likely habitat for the Rare Pyrus, all the more that a young plant grows near its junction with the stream. I determined to examine it. I was rewarded by finding the Rare Pyrus in consider- able abundance. One of the plants, of the intermediate type, had the largest leaves I had yet noticed in any of the varieties—one, not including stalk, 5x34 inches. Here also I found a specimen of Sedum Telephium. 1 passed over the ridge, and descended the gorge on the opposite side. Great abundance in it of Pyrus Aucuparia, and of the Aspen; but none of the Rare Pyrus. Third Successful Exeursion—At the mouth of Glen Catacol is an amphitheatre of level ground, with a radius of half a mile. It has evidently been formed by detritus brought by the stream. In addition to the Catacol, four little torrents flow into it. The course of the two on the south side I examined without success. So also on the north, the Abhain Bheag (the Little Stream). But at the north-east corner is the Uisge Solus (the Water of Light, ae, the Sparkling Water). This is a remarkable stream. It is a main stream, and not a tributary. It comes down the side of a high steep, leaping and dancing in many a foamy fall, resembling the White Water at Corrie, only the falls more numerous and the body of water less. It was not likely to have on its banks the Rare Pyrus, as it was near the sea, and the rock was slate, while this Pyrus had hitherto been found only in the granite, and at a distance from the sea. The stream, however, was inviting, and I ascended. I had gone only half a mile (afterwards measured), and to the height of 400 feet, when, on passing a little sheep bridge, I came upon the Rare Pyrus, which continued at intervals till the bare moorland was almost reached. A number of things were notable. (1st) There was good shelter, for it was a cross stream, that is, a tributary, and thus not exposed to the tremendous blasts which render tree-life almost impossible in the great glens. (2nd) The stream abounded in little waterfalls, presenting specially cosy nooks. (3rd) The rock is contorted schist, “gnarled and twisted, with many minute cross grains” (Smith), which decomposes into a soil specially suitable for nourishing plants, while its many crevices provide 60 TRANSACTIONS AND PROCEEDINGS OF THE [Szss. 1x1. abundant hold for their roots. (4th) There is here a rare union of flora—Hawthorn (long stemmed and very narrow leaves), Honeysuckle, Scotch Rose, Juniper, Lycopodium, the Common Butterwort and the rare Seaside Butterwort (Pinquicula lusitanica), the Red Bearberry, this Rare Pyrus, Birch, Rowan, ete. (5th) The Rare Pyrus was all of one variety, the pinnate. It was the most pinnate I had seen in Arran, generally three of the lower segments cut to the mid-rib, while in those found at other stations rarely are even two of the lower segments thus deeply cut. (6th) This station is further remarkable as being situated in the slate, while all the others are in the granite; and also from being near the sea, only three-quarters of a mile from it, while those known previously are from 24 to 6. The discovery of this station is thus of special import- anze, as It introduces new data into the questions regarding the Rare Pyrus. Fourth Successful Excursion—The Rey. Duncan M‘Nicol, Dunoon, informed me that the Rare Pyrus grew at the stream side, near the foot of the steep ascent at the head of Glen Catacol. I visited the place and found a consider- able number. I ascended here Allt-na-Calmen (the Dove’s Glen-side Stream), the highest tributary of the Catacol. In it are various cascades, and beside them are a dozen of the Rare Pyrus. The peculiarity here is that it is much more common than the Rowan, of which there is only one tree standing. SUMMARY. I. By Mr. Smith’s discovery and my own, the number of main streams in which the Rare Pyrus is known to grow has been doubled—from two to four. II. By Mr. Smith’s discovery and my further search, it has been shown that the Rare Pyrus is not confined to the north of the dividing ridge in the north of Arran—that is, to the north of Loch-na-Davie and Loch Tana—but has an established habitat several miles south of this ridge. Ill. It has been shown that it is not confined to the granite area, nor to a distance from the coast-line. IV. Its range in altitude has also been increased It . j 4 : JuLy 1897.] BOTANICAL SOCIETY OF EDINBURGH 61 is from 300 feet in the Iorsa tributary, to 1100 feet on the north side of the range of North Sannox. V. There are three varieties in Arran—(lst) the leaf narrow, little cut, very white, downy underneath, and slightly downy on the upper side; this is by much the most rare: (2nd) that which has the largest leaf, not so downy as the previous, pinnatifid, but seldom pinnate, running however into the third: (3rd) the three lower segments of the leaf generally pinnate. VI. That the trees in the little stream at Catacol, where there is proximity to the sea and the rock—not granite but a slate—are all of the third variety. VII. The form of the tree conforms to the shape of the leaf. This is very notable in the first variety. In it the leaf being narrow, the branches and twigs are slender and drooping. VIII. The bloom of all is fragrant. IX. The range of the Rare Pyrus in Arran corresponds to that of the Red-berried Bearberry (Arctostaphylus Uva- CUrsi). This plant had previously been noted in the Holy Isle. The writer was the first to notice it in Arran proper. He now adds that he has found it in the neighbourhood of all the habitats of the Rare Pyrus, and that he does not know of it being found elsewhere in Arran. X. The known stations of the Rare Pyrus in Arran are— (1st) the Allt-an-Champ, a tributary of the Iorsa, fully two miles south of Loch-na-Davie; (2nd) a stream on the northern slope, at the head of the North Sannox range ; (5rd) the three streams into which the Easan Biorach divides at the foot of the steep slope to Loch-na-Davie, that on the east being the lower part of the same stream mentioned in number 2; (4th) the stream (not a tributary) at the mouth of the Catacol ; (5th) the eastern head of the Catacol ; (6th) the eastern tributary to it; (7th) the head of the Catacol ; (8th) Allt-na-Calmen, the Catacol’s highest tributary — ten stations in all. XI. In a letter to Professor Balfour, of which he was so kind as send me a copy, Professor Koehne, of Berlin, writes: “ Messrs. Ley and Landsborough, if they search more carefully, will find forms of the Rare Arran Pyrus, scarcely to be distinguished from Sorbus Aucuparia, since they have > 62 TRANSACTIONS AND PROCEEDINGS OF THE completely pinnate leaves, the upper leaves, however, a little decurrent on the mid-rib of the compound leaf, or are slightly fused together.” To some extent this has been realised, but the belief of the writer is that no more careful search in the formerly known habitats would have so resulted. It is entirely owing to the discovery of the new habitat in slate rock, and near the sea, in the Uisge Solus, at the mouth of Glen Catacol. I send leaves of (1st) the narrow-leaved variety, gathered from a tree on the west tributary at the head of Easan Biorach (Lochranza Stream) ; (2nd) the intermediate variety, from the tributary stream to the eastern head-water of the Catacol; (5rd) the Pinnate variety, from the Uisge Solus. I forward, also, the Ordnance Survey map of the north of Arran, on which I have encircled in red the area in which the Rare Pyrus has been found. NoTEs ON GLEICHENIAS. By PercrvaL C. WAITE. (Read 12th April 1894.) The following is an abstract of the chief characteristics which I have observed :— I. In the Mertensias the bundle of the petiole, as seen in T.S., is curved into a () shape; in the Lngleichenias the arms of the bundle unite, so that the cortex embraced by them, together with the portion of bundle-sheath which separates the cortex from the bundle, is nipped off. We have thus an annular bundle surrounded by its bundle- sheath, and containing within it a portion of the outer cortex with a few cells of the bundle-sheath surrounding it. This is the case in the young petiole; later on this inner patch of cortex disappears. That this pecuhar arrangement of the bundle is developed in the way above described may be proved by examining the petiole of the Lngleichenias, at different levels, as it emerges from the rhizome, where transition stages may be observed. There is first a stage resembling the arrangement in the Mertensias, then a little higher up . ¥ a ‘ a BOTANICAL SOCIETY OF EDINBURGH 63 the approach of the arms cutting through the neck of cortex which joins that inside to the surrounding mass, and, finally, the disappearance of this central portion of cortex and inner ring of bundle-sheath. Il. The bundle-sheath in the petiole and rhizome does not appear as a cortical layer similar to the bundle-sheath {endodermis) of roots, since the cortical cells do not lie opposite the cells of the bundle-sheath, but seem to form part of the bundle itself; it, however, shows the characters of the typical endodermis, with dark dots on the radial walls, and no intercellular spaces. The inner layer of the cortex is not differentiated from the other cortical layers. Ill. The layers of cells internal to the bundle-sheath are derived from it by division of its cells, and these divisions begin at a short distance below the apex, but do not form a pericycle. IV. The spore of the Mertensias is reniform; round and marked with a triradiate line in the Engleichenias. I consider that the differences in spores, petiolar bundles, general growth and appearance of the plants, justify the greater distinction formerly made between the JMertensias and Hngleichenias, when they were considered as different genera, and that these characters are sufficient to prevent the two genera being classified as merely sections of one genus. MORRISON AND GIBB LIMITED, PRINTERS, EDINBURGH. ; > ‘ ee es ae a » * il oh a cm bre ‘ , ni y i er a, eee TRANSACTIONS AND PROCEEDINGS OF THE BOTANICAL SOCIETY OF EDINBURGH. SESSION LXII, ADDRESS DELIVERED AT THE OPENING OF THE SESSION BY Professor A. P. AITKEN, M.A., D.Sc., President of the Society. —11th November 1897. At the meeting of the Society at this time last year I chose as the subject of my address “The Nitrogenous Food of Plants,” for the reason that it was a subject in itself interesting, and on which our knowledge was being rapidly developed, and also because, in treating it from a historical point of view, I might prepare the way for other papers of a practical kind on that subject that were to be read before the Society. The attention of the fellows was chiefly directed to the somewhat recent discovery that leguminous plants, and more especially those of the sub-order Papilionacex, possessed, in a remarkable manner, the power of assimilating the free nitrogen of the air and of converting it into their own albuminoid tissue. The interest attached to this dis- covery was greatly enhanced from two causes—first, because authorities of the highest repute in the domains of botany, chemistry, and agriculture, had, after what seemed to be satisfactory and complete investigation, considered that they were warranted in making the pronouncement that plants did not possess that power; and in the second place, that when, after fifty years’ negation, it was at length put beyond doubt that leguminous plants did possess that power, it was shown, at the same time, that they possessed it, not in themselves, but only when their life were TRANS. BOT. SOC. EDIN. VOL. XXI. F 66 TRANSACTIONS AND PROCEEDINGS OF THE [Sess. uxu. associated with the life of an exceedingly minute organism affecting their roots, causing the development thereon of nodules, in which they lived and brought about changes that were favourable to the growth of their host. Instances in which two distinct organisms, each living its own life, are associated together for their mutual advan- tage, are not infrequent in the animal world, and the word Symbiosis has been coined by De Barry to express that relationship. The classical researches of Darwin have familiarised us with instances of symbiosis between animals and vegetables, and have shown, with great wealth of illustra- tion, how much plants are dependent on insects for their cross fertilisation, and how whole species of plants may be dependent for their existence upon the regular and unfailing visitation of insects, and, on the other hand, how certain species of insects are dependent on certain species of plants for their food, which they obtain from no other source. ‘The visits of a determinate species of insect to a certain species of plant may be without any benefit what- ever to the plant. In that case, the relation of the insect to the plant is simply that of a parasite feeding on food provided by another, and giving nothing in exchange, and in abstracting its food from its host, it may not only do it some injury, but may even injure it so far as to kill it outright. The various species of aphides are an example of that kind. They are very numerous, and exhibit very distinct characteristics according to the kind of plant on which they feed. In how far species of aphis which are found constantly associated with one genus of plants could accommodate themselves to, and find means of subsistence upon, other genera I do not know, but the probability is that in few cases could the parasite subsist under the altered conditions. In such a case the insect has some modification of structure or of function suited to the particular genus on which it lives; but what we require to find in a case of symbiosis is, that the plant also has acquired a modification of structure suited to the char- acteristics of the insect which feeds on it. What we fail to find in pure parasitism is mutual adaptation, with the ultimate result of mutual advantage. Darwin and others after him have shown how the forms of flowers in some Noy. 1897.] | BOTANICAL SOCIETY OF EDINBURGH 67 species have been modified to suit the convenience of their insect visitors, and how the colour had been acquired to allure them; but in such cases the object of the insect’s visit, so far as it was concerned, was entirely to satisfy its own wants, yet, in so doing, it ministered unconsciously to the welfare of the plant it visited. Instances of such mutually advantageous connection between plants and insects are numerous, but cases in which plants of widely different order have been found to live in symbiosis with each other are, so far as I am aware, of rare occurrence. There are, however, two very notable instances of plant symbiosis which I would take the opportunity of referring to, though they are probably familiar to all who are here present. In examining under the microscope the substance of lichens, such as those to which old wayside walls owe their beauty and colour, it is noticed that, while the moss of the structure is composed of a fungus-like arrangement of tissue, having a mycelium whose long hyphe form a vegeta- tive network over the stone, penetrating its fine crevices, and, while there are disposed on some part of the organism the ordinary fungoid organs of reproduction, there are also to be found, entangled or entrapped within the body of the lichen, a number of little green-coloured cells, which in botanical treatises were called gonidia, and whose object in the economy of the lichen and connection therewith were not understood. But for the presence of these green- coloured cells, the plant would probably have been called a fungus. It was not until a few years ago that Schwendener, from a careful study of the matter, came to the conclusion that what were described as lichens were not a distinct elass of plant at all, but really a copartnery of two quite distinct organisms—a fungus and an alga. A fungus is a plant which, however varied its form and habit may be, is distinguished by one characteristic peculiarity, that it cannot make its own organic matter, but can only vegetate upon the organic matter made for it by other plants. On a bare wall a lichen cannot find that organic matter, for no vegetable organisms preceding it in time have left behind them residues in the form of organic matter sufficient for its needs. The only way in which-a lichen can grow im 68 TRANSACTIONS AND PROCEEDINGS OF THE [Szss, xm, such circumstances is by getting into co-operation with a plant that can make organic matter. Algze are the most convenient plants of that kind. They are provided with chlorophyll, and in their chlorophyll cells proceeds the wonderful process by which the carbon derived from the carbonic acid of the air is assimilated so as to form sugar, starch, and cellulose, and other organic matters. The small ereen-coloured cells enfolded in the fungus substance of the lichen are unicellular alge, which have been caught by it in some way. They have no roots, and are unprovided with the means of obtaining their mineral requirements from the soil. Thus we see in the lichen two distinct vegetable organisms closely associated for their mutual benefit—a fungus, whose mycelium, acting the part of roots, can find on the barest stone the mineral constituents necessary for plant growth, and an alga possessed of the power of obtaining from the air the carbon required to build up the organic tissues of the plant. That the lichen is really a composite plant of that kind has been proved in a very interesting way. Rees and Stahl chose fungi of various kinds, and also algz of various kinds, and by bringing them together brought about the conditions of lichens quite similar to known species, and by bringing together a species of lichen and a species of alga that had not been seen associated together before, they were able to manufacture what would have been called a new species of lichen, In course of time the fungus, having grown and flourished, and developed its organs of reproduction and produced a large number of fertilised spores, which are its seed, disintegrates and sets free the unicellular algze, which on their part have increased in number, and the two kinds of organisms are now ready to be blown away by the wind or carried away by water, and enabled to propagate a new generation of fungi and a new generation of algze capable of leading single lives in suitable circumstances, or of getting into symbiotic relationship of a similar, or it may be of a quite different, kind from that under which they had been nurtured. The second instance of plant symbiosis to which I would shortly refer, is one which is not only interesting, but of far-reaching importance, ee ee indeed, ott ae Noy. 1897.] BOTANICAL SOCIETY OF EDINBURGH 69 In 1885 Professor Frank published in the “ Berichte der Deutschen Botanischen Gesellschaft” a remarkable paper, explaining in a quite unexpected manner the mean- ing of the fungoid mantle which had been noticed in the fine roots of the Scots -fir, Pinus sylvestris, a few years previously by Rees. He found that not only in the case of the Scots fir, but also in the case of other conifers, and also most markedly in the case of the Cupuliferze, such as beech and the hazel, the finer and trophic roots were thickly en- veloped in the mycelium of a fungus. The constant occurrence of this fungoid envelope on the roots of all the trees of these orders persuaded him that it could not be an accident, and as he found that it existed on the roots of even the youngest and healthiest specimens, he felt satisfied that it could not be a parasite, or at least a destructive parasite. Heat once conceived the idea that this was a case of symbiosis, and worked diligently at the investigation of the roots of a great variety of plants from that standpoint. Among these were roots that had been sent to him from all quarters of the globe, and its presence in them all showed that the fungus was universally dis- tributed. This fungus, like others, lives upon organic matter provided for it by other plants. It is found as a fine thread-like mycelium ramifying through the mass of organic matter left by the fallen leaves and débris of forest trees, and is not met with where that organic matter is wanting. When a conifer or cupulifer is planted in such soil, it is not long before its roots are fastened upon by this fungus, and in time the growing points of the roots become closely wrapped round with it. In ordinary circumstances the growing rootlets of plants are beset with fine hairs, through whose delicate walls the nutritive mineral matter in an available soluble form passes from the soil into the circulation of the plant. In the case of the two orders referred to, when the fungus has established itself, the trophic rootlets have no _ hairs. Their place is taken by the fungus, from which proceed numerous fine filaments, that at first sight might be mistaken for hairs, but which, on microscopic examination, are seen to be aggregated mycelium filaments. That these 70 TRANSACTIONS AND PROCEEDINGS OF THE [Szss. LXI. filaments take upon themselves the office of roots he could not doubt, for owing to their universal distribution all over the growing root system of the plant, and the entire suppression of the root hairs, there was no other way in which the trees could obtain soil nourishment. It would thus seem that the fungus acted towards the tree the part of a nurse. Its delicate filaments, ramifying through the mass of organic débris, absorbed the nutritive matter found there ready made, and poured it into the roots of the trees. If that is a true account of what takes place in the nourishment of forest trees, it must be regarded as revolu- tionising our views regarding the physiology of plant nutrition. If the mineral food which these trees require is supplied to them by the organic sap of the fungus, it must be supplied in some form of organic combination, and in that case the trees must owe, not only their mineral, but also some of their organic constituents to the fungus that feeds them. Before the days of Liebig, that is to say during last century and a considerable part of this one, it was universally believed that plants obtained their organic matter from the soil, and humus was regarded as the one essential of fertility. The accumulation of humus in the soil was the aim the cultivator of the soil had before him ; and when we consider that it was the leading principle guiding the most intelligent farmers in their operations for centuries, there must have been, and there must still be, a good deal of permanent truth in it. It was Liebig’s greatest achievement to fight against and completely demolish this view, and cause it to be superseded by what was called by him the mineral theory of plant nutrition. This theory established, on the firm basis of actual experiment, the fact that plants did not require to be supplied with organic matter, that, on the contrary, it was the great function of their life to manufacture organic matter; and perfectly unexceptional experiments were carried out in which the plants of our ordinary field crops, chiefly cereals, were grown both in aqueous solutions and in mere sand containing no organic matter whatever, but only solutions of certain salts containing the mineral nourishment that the plants required, The organic matter of plants was proved to be made in their leaves, while the eo Al WE Se “ee 6 tll Noy. 1897.] BOTANICAL SOCIETY OF EDINBURGH 71 mineral matters required to enable the leaves to make this organic matter was abstracted from the soil by the roots. It cannot be doubted, for a vast mass of experimental evidence is at hand to prove it, that that describes what is in the main the theory of the nutrition of phanerogamous plants; but while that is so, we must not regard as altogether absurd and out of the question the probability that the roots of phanerogamous plants may in some way be able to absorb organic matter. That the plants can do without the absorption of organic matter is not a proof that they do do without it. Our forefathers were well aware that in the accumulation of organic matter at the roots of plants, lay the success of husbandry. Since their time we have come to know that by the addition to the soil of what are called fertilisers, which are frequently mineral substances contain- ing no organic matters, a great increase of crop can be obtained ; but evidence is not wanting to show that during recent times the mere application of fertilisers has been in many cases overdone, to the detriment of the texture and condition, and even to the fertility of the soil. The result is that at the present time there is a renewed appreciation among the best farmers of the great value of organic matter as an ingredient of the soil on which its fertility depends. If the observations of Professor Frank be correct, some- thing will have been done to reconcile two views of plant nutrition that have hitherto been sharply at variance; but there are some difficulties to overcome before his theory of the symbiotic relation of the fungus, which he calls a Mycorhiza, and the forest trees can be accepted, in so far at least as the fungus is able to be regarded as supplying the roots of the tree with organic matter. An obvious objection to this view is that conifers and cupuliferous trees are pro- vided with leaves whereby they can make their own organic matter; but,on the other hand, it may be said that there is no reason why trees should not obtain their organic matter from two sources. The one important observation which he adduces in support of that view is, that in the roots of trees nourished by the mycorhiza no nitrates are found. That is certainly a remarkable circumstance, which very distinctly differentiates them from most other plants in whose roots 72 TRANSACTIONS AND PROCEEDINGS OF THE [Szss. Lxu. nitrates are found as a constant constituent. Necent researches have shown that the nitrogenous matters in the soil, which are chiefly there in the form of albuminoid substances—the residues of former plants—are, in the process of decay, converted into ammonia salts, and these again into nitrates, through the agency of various bacteria inhabiting the soil; and that theseorganisms are so abundant and, in ordinary circumstances, so active that all nitrogenous matters which have become soluble in the soil are ultimately converted into nitrates, and that in that state they are absorbed by the roots of plants, and by means of proper chemical tests their presence can be detected. Professor Frank observes that in the roots of trees or other plants affected by the mycorhiza he has _ not succeeded in finding nitrates, and this would seem to show that these roots are receiving their nitrogen from the mycorhiza in the condition of nitrogenous organic substances, viz. of elaborated organic matter such as is found in humus. It may be objected to the symbiotic theory that conifers and cupuliferze can be grown in soil containing no organic matter. That is quite certain, and Professor Frank gives details of many experiments where trees of these orders were planted in sandy soils containing no mycorhiza both in pots and in the open, and in such cases no mycorhiza appeared upon the roots of the plants. They had the characters of normal roots, provided with hairs like the roots of other plants, and capable of taking up the soluble mineral matters contained in the soil. But he found that in such cases the plants, if they did not die down, maintained a sickly growth, which contrasted strongly with that of plants sown or planted under similar con- ditions, with the sole difference that they were supplied with humus in which the hyphe of the mycorhiza were abundant. The benefit that forest trees derive from the accumula- tion at their roots of the dead leaves and vegetable débris shed from above is known to all foresters, and also the injurious effects which follow the removal of this vegetable matter. It had hitherto been supposed that the benefit the roots derived from the covering of decaying vegetable stuff was simply that of protection against extremes of heat and * Noy. 1897.] | BOTANICAL SOCIETY OF EDINBURGH 73 cold, and of drought and washing, the maintenance of an equable temperature and an equable dampness, both of which are favourable to the decay of vegetable matter, and its conversion into humus, which, besides vegetable matter, contains also the mineral substances most essential for the nourishment of plants. But if Frank’s observations are thoroughly to be relied on, it would seem that humus has become invested with a new interest, as the dwelling-place, namely, of a fungus which assimilates what is most useful as plant food and conveys it to the roots of the trees. So far from the mycorhiza being a parasite invading the trees, it would rather seem that the trees themselves were the parasites living on the fungus. ; In order that a true case of symbiosis may be established, it would be necessary to show that the advantages enjoyed by the trees from the association with the fungus were reciprocated in some way. If the roots of the trees provided a nesting place for the fungus where it was able to breed or perform some function essential or advantageous to its development, then it might fairly be called a case of sym- biosis. It seems, however, that only the vegetative part of this universally distributed fungus has as yet been found, and it is not known whether the process of reproduction takes place in the soil or in the roots of the trees, and, until that is known, the truly symbiotic character of it can be but imperfectly understood. It would seem, how- ever, that its connection with the roots has this advantage, that it puts it in a position where it grows immensely more luxuriantly than it does when remaining unattached in the soil. Since Frank’s original paper was published, several investigators have made observations on the subject, with the result that the mycorhiza has been found affecting many other plants, notably Ericas and Orchids, and a number of plants whose connection with the soil, or I should rather say want of connection, has been a puzzle to botanists, such as Paris quadrifolia and the Droseras, which Schlicht, a pupil of Frank’s, has been able to identify as mycorhiza affecting internally the roots of a large number of plants belonging to many natural orders. To return to the subject of the assimilation of the free 74 TRANSACTIONS AND PROCEEDINGS OF THE [ Sess. LXII. nitrogen of the air by leguminous plants, you may remem- ber that a very considerable body of evidence was adduced in support of the view that that order of plants possessed the power in virtue of their living in symbiosis with the Bacillus radicicola of Beyerinck, or, as Frank called it, the Rhizobium leqguminosarum. That the Leguminose possessed a means of obtaining nitrogen which was denied to other orders, or at least possessed by them in a very subordinate degree, was known for ages; but it was not until quite recent years, culminating in Hellriegel’s experiments, and recorded in 1886, that it was satisfactorily proved that the store of nitrogen which the leguminous plants were able to tap so freely was the uncombined nitrogen of the air, and that this power was associated with the growth of the nodules which that order of plants develop so abundantly upon their roots. Since the publication of Hellriegel’s investigation, the formation and function of these nodules have been a subject of scientific research in all parts of the world, and these researches have been chiefly devised with the view of testing the accuracy of the symbiotic theory. To the results of such of these researches as have come under my notice, I wish now shortly to refer, If the roots of the ordinary leguminous plants grown in the open field are examined, it will rarely happen that they are found entirely devoid of nodules. Nevertheless, in certain soils it is not uncommon to find good, healthy specimens that are quite free of nodules, showing that nodules are not absolutely essential to their development. Some genera are more prone to nodulation than others, and among these the lupine is pre-eminent. The lupine is also distinguished among leguminous plants as best adapted for green manuring, on account of the large amount of nitrogen which it is able to assimilate. But lupines also may be found growing vigorously without nodules. That the nodules on the roots of leguminous plants are caused by the attack of a micro-organism in the soil is easily proved by growing the plants in a soil that has been sterilised by heat or otherwise, when it is found that no nodules then make their appearance. If to such a sterilised soil a few grains of unsterilised soil, or a few ——— se Pi © re een ee al Bye as Noy. 1897.] BOTANICAL SOCIETY OF EDINBURGH 75 drops of the washings of such a soil, be added, the roots of the plant are liable to develop nodules, and that lability becomes a certainty if the unsterilised soil is one in which similar plants well supplied with nodules have been growing. The nodules make their appearance at a very early stage in the plant's history usually, but it is not unusual to find quite newly-formed nodules on the roots of plants that are well advanced towards maturity. Nodula- tion may occur on the roots of almost any plants, and the nodules may be due to a variety of causes. The nodules here referred to are, however, of a special kind, and their anatomy has been carefully studied. They are due to the attack of a special organism. The generally accepted view is that it is a bacterium, and that it enters the plant by the hairs of the root. To discover the plan and mode of attack, and the propagation of the organism through the root tissue, is a matter of extreme difficulty, and it is not to be wondered at that there is considerable diversity of opinion regarding such matters. Frank, after much research, thinks he has discovered the spot on the root where a nodule will be formed, and around which will be clustered a mass of bacteria, allured to the spot by some inviting exudation emitted by the plant itself on purpose to attract them. When the nodule has at length been formed, the changes brought about in the tissues of the root are easily seen. In a diagram of Frank’s there is shown a microscopic preparation where the nodule from the root of a pea is permeated by what seems like the hypha of a fungus that has gained entrance by a hair and forced its way through the epidermis and cortical layer, and has caused the formation of modified cells in the meristem. These celis, under a high power, are found to be full of small Y-shaped bodies, to which the name of bacteroids has been given, and within the bacteroid are found very small highly refractive cocci, which are the bacteria which Frank calls Rhizobium leguminosarum. In another diagram is shown a section of a nodule, taken from the root of yellow lupine, in which the infection has spread over a considerable part of the meristem, and it is important to note how the cells have multiplied by 76 TRANSACTIONS AND PROCEEDINGS OF THE [Szss. rxu. division, and how the dividing cells are arranging them- selves in rows perpendicular to the point of attack in front of, and circumscribing, the infected cells, and, as it were, setting up a barrier between them and the endodermis and the vascular bundles farther in, which give access to the circulating system of the plant. I seem to see in this arrangement an effort of the plant to oppose the advance of the intruder, and prevent, if possible, his gaining access to the vascular tissue within. The way in which one interprets such things is hable to take its form from the preconceived notion he has entertained regarding it. Frank starts with the notion that this is a case of symbiosis, and he imagines the plant as fishing in the soil for the bacterium, preparing a door for it, and entertaining it within its root as a wel- come guest. . The manner in which the cells of the root increase and stand in between the infected cells and the vascular centre, pushing them out farther and farther until an excrescence in the form of a warty growth is made, calls to mind what takes place in animal bodies when invaded by parasites such as tubercle. The healthy tissue surrounding the intruder raises up a wall of defence, and endeavours to encapsule it, and so prevents it spreading. The bacteroids may, perhaps, not inaptly be compared with the phagocytes, which Metchnikof describes as mustering in force around the seat of an invasion, and not only surrounding, but incorporating the invading crowd of bacteria. Either view of the matter is not inconsistent with the further development of the nodule, which increases often to a great size, and is usually connected with the root by a narrow neck. Also there is, if not always, at least usually, established a connection between the nodule and the vascular tissue, and the organisms within the nodule increase so as eventually almost to fill it. These organisms, be they bacteria or bacteroids, or both, are bodies rich in albumen, which is a highly nitrogenous compound. The source of this albumen is a very vexed question. There are those who hold that the bacteria within the nodule get their nitrogen from the elementary nitrogen contained in the ground air. I believe that is the view which is generally entertained. It must, however, seem a ee — Noy, 1897.] | BOTANICAL SOCIETY OF EDINBURGH 7 curious circumstance that the bacteria, if such is their function, should exercise it through the thick, corky layer of cells in which they are enclosed in the nodule, and that as they increase in number, and correspondingly in their demand for nitrogen, the wall surrounding them should be gradually becoming less permeable. This is at variance with what is found in other parts of the plant, such as in the chlorophyll cells surrounding the stomata, where the walls of the cells are made exceedingly thin, in proportion to the activity with which gases are required to diffuse through them. To discover whether nitrogen gas is entering the nodule through the walls is a very difficult matter, So far as it has been attempted by Kossowitch, who grew nodulate plants in a soil supplied with an artificial atmosphere composed of hydrogen and oxygen, but containing no nitrogen, it has gone to show that nodules grow independently of soil nitrogen. One would naturally expect that if the nodules were for the purpose of absorbing nitrogen, they would be provided with delicate hairs, or in some way present an easily permeable membrane to the gas; but there is no such means provided, and there has been adduced no positive evidence in favour of the view that the nodule is a gas- absorbing structure. It has been suggested that the forked bacteroids within the nodule arrange themselves in a loose fashion, forming a network which presents a large surface to nitrogen gas, after the manner of the lungs of animals. This seems to me a fanciful notion, as it is highly improb- able that a lung-like provision should be made for air which was not allowed access thereto. We may now consider the other view held by Frank, and in which he is supported by Schlosing and Laurent, that the place where nitrogen assimilation takes place is the same as that wherein carbon assimilation takes place, viz. in the green leaves and other chlorophyll-containing parts of the plant. In support of that view there is the one very important piece of evidence, that the function of absorbing and assimilating atmospheric nitrogen and converting it into vegetable tissue has been. shown by Berthellot, and André, and others, to be possessed by unicellular alge which inhabit ordinary soils abundantly. 78 TRANSACTIONS AND PROCEEDINGS OF THE [Sess. rx. These unicellular plants containing chlorophyll are quite comparable with the single chlorophyll cells of compound plants, and are so like them in every way as to make it very difficult to deny to them the power of assimilating free nitrogen. But while that goes so far as to make it a reasonable view, it does not explain why it is that the faculty of absorbing free nitrogen should be possessed by the chloro- phyll cells of the Leguminosze any more than by those of any other order of chlorophyll-bearing plants. Frank has endeavoured to throw some light on this by following up, as far as possible, the fate and progress of the bacteroids within the nodules and without. From a minute examina- tion of the tissues of the root in the neighbourhood of the nodules, he finds that these organisms make their escape from the nodule in the root, and that they are to be found there especially in the riper stages of its life. It is his belief that long before the nodule softens and breaks down, and is in great measure absorbed by the plant, it is passing its bacteroids into the general circulation ; and he has been able to detect these Y-shaped or forked organisms in the cells of the stem, the leaves, the seed itself, and even in the cotyledons of the young embryo of Phaseolus vulgaris. The identification of these minute organisms is attended with great difficulty, and there is considerable liability to error ; but Frank is very strong upon the point that he is not mistaken in his search for these bodies, and if that is so, if his observation is to be trusted, and if it is really certain that the plant is permeated even very thinly with bacteroids, it makes it more easy to believe that under their stimulus the function of absorption of free nitrogen may be imparted to the chlorophyll cells, in virtue of their presence in some unknown way. It would, in that case, be more easy to compare the chlorophyll cell of the Leguminose with the unicellular algze of the soil, for it is quite possible that these also owe their power of assimilating free nitrogen to a stimulus received from similar bacteria contained in the soil. The finding of bacteroids in the cotyledons of Phaseolus vulgaris is also a matter of great interest, for if that is correct, and if the case is not an isolated one, it is evident a 4) (eae A Noy. 1897. ] BOTANICAL SOCIETY OF EDINBURGH 79 that the plant contains within it the means of producing nodules on its roots without having to be dependent on the friendly co-operation of bacteria resident in the soil. More- over, if it were so, it should be possible to grow leguminous plants having nodules on their roots, even in a sterilised soil. That, however, is against all experience, for there is nothing on the subject regarding which experimenters are more agreed than that the plants grown in a sterilised soil should have no nodules on their roots. Another important observation that militates against the view that the bacteria or bacteroids in the nodule are the direct assimilators of free nitrogen, is that when cultivations of the bacteria are made outside the plant in nutritive media containing organic matter of a suitable kind, they have not been found to absorb atmospheric nitrogen. They live upon the nitrogen contained in the nutritive solution, just as other bacteria do. It will thus appear that the view that the free nitrogen assimilation takes place in the chlorophyll cells has by far the most support from experimental facts. If that be so, then the store of albuminoid matter found in the nodules has not been brought to the plant as a free gift—it has been supplied by the plant itself, and the question arises: Is this then a case of symbiosis? Is it not rather a case of pure parasitism, where the invading organism is preying upon the tissues of its host? If it could be shown that the host was impoverished thereby, and especially if it were injured, that would be the true name for it; but it is alleged that the host plant is greatly benefited, inasmuch as the stimulus derived from the bacteria enables it to assimilate far more nitrogen than it otherwise could, and that even that which goes to the nourishment of the nodule is only lent it for a time. As soon as the life cycle of the bacteria is over, the nodule falls into a state of decay, and the host reabsorbs the albuminoid matter that he has stored in the nodule as a surplus manufacture. True it is that, in the breaking down of the nodule, some of its contents escape into the soil, but that is regarded as an additional proof of the symbiotic relationship, for the bacteria which escape into the soil remain there, and, for ought we know, increase 80 TRANSACTIONS AND PROCEEDINGS OF THE [Szss, Lxu. and prepare themselves for bestowing a similar service upon the succeeding generation of leguminous plants, t must be evident that in all this complicated symbiotic arrangement, an instance is presented to us of the danger of proceeding to investigate a chain of natural phenomena with a preconceived theory to which you hope that the facts will accommodate themselves. According to Frank, we are asked to believe that the plant baits its roots with something nice, to lure the bacteria to it; it opens the door to them, and leads them along through a lane into the body of the root, where they find a number of expectant cells organising themselves for their reception. These surround the bacteria as a kind of bodyguard, and conduct them to the vessels that enable them to enter the circulation of the plant. The plant constructs a special abode for them, and supplies them with nourishment, whereby they may increase and multiply; and only when it requires a large amount of albumen for the development and ripening of its seed, does it claim back the albumen it had lent. At the same time, with a prudent eye to the future, it allows a residue of the organisms to escape into the soil, sufficient in number to satisfy the requirements of all its progeny in the coming season. The symbiosis consists in this, that the plant supplies the bacterium with a breeding place and a store of food, and receives from the bacterium in return a stimulus which enables it to assimilate the free nitrogen of the air. This is an interesting theory, but it will be thought by many that it claims for the Leguminose a little too much intelligence, cunning, and providential care, There is a liability in working out a theory to select (unconsciously it may be) only those facts which fit in with it. Since the broaching of the symbiotic theory, other facts have come to light that can scarcely be said to fit in with it, When Hellriegel first recorded his experiments he claimed for the nodules this advantage, that they enabled the young plants to assimilate atmospheric nitrogen at the precarious period of the youth when they had used up the nutriment stored in the cotyledons, and were thrown upon their own resources, This does not accord with the general experience of investigators, who find that the advantage to the plant is eee ee ee ee eee “— 9 Noy. 1897.] BOTANICAL SOCIETY OF EDINBURGH 81 observable only during the latter part of its growth, when its seed is forming. As I have already observed, leguminous plants can grow to maturity quite well without the possession of nodules, so long as the nitrogenous matter they require for their growth ean be obtained easily from the soil. Plants grown in a sterilised soil and supplied with nitrates, as well as the other plant food required, grow to perfection, and in a natural unsterilised soil, rich in plant food, where the assistance of nodules to enable the plants to obtain nitrogen from the air is unnecessary, they may have their roots abundantly studded with nodules. Frank describes an experiment with Phaseolus vulgaris grown in a poor sandy soil containing only about ‘01 per cent. of nitrogen, where the plants grown in sterilised pots and unsterilised pots, with inoculated and uninoculated, grew in very much the same way, and that very poorly ; and when grown in a soil rich with nitrogenous organic matter the beans grew exceedingly well, but quite indifferently as to whether it had been previously sterilised or not, or whether it had been in- oculated or not. He came to the conclusion that Phaseolus behaved toward the Rhizobiwm as if it were a non-leguminous plant, but that, you may remember, was the plant within whose cotyledons he succeeded in tracing the presence of bacteroids. A very instructive series of experiments was carried out by Dr. Stocklasa in 1894, with the view of ascertaining whether there was any necessary connection between nodule formation and the formation of nitrogenous tissue in leguminous plants, and he chose for his subject of experiment Lupinus angustifolius, which he grew upon a light sandy loam, poor in nitrogen, in the open field. He selected, while in bloom, ten well-grown plants with nodules on their roots, and ten others of similar growth without nodules. The two sets of plants were as equal in every way as could be wished, having twenty-three and twenty-two leaves per plant respectively. These he analysed, and found that there was practically no difference in the amount of nitrogen they contained. The only difference noticed was that the nitrogen was somewhat unequally distributed. The plants with nodules had rather more TRANS, BOT, SOC. EDIN. VOL, XXI, G 82 TRANSACTIONS AND PROCEEDINGS OF THE [Sess. LXi. nitrogen in their roots, those without nodules had rather more in their leaves. The nodules themselves contained as much as 4'5 per cent. of nitrogen. He also grew lupines in pots containing washed sand, to which he added fertilising niaterials such as plants require, in the form of a solution made perfectly sterile, and with which the plants were watered, but in this nutritive solution there was no nitrogenous matter. Moreover, the pots were covered with wadding to protect them from infection of any kind by means of air-borne spores. Ten lupine plants thus grown assimilated from the air ‘191 grams nitrogen. These roots had no nodules. Ten lupine plants treated in the same way and grown in the same kind of soil, to which a few grams of unsterilised lupine soil were added so as to inoculate the earth, assimilated 1575 grams of air nitrogen, viz. about eight times as much as the others, and their roots were well studded with nodules. So much for the lupines grown in sterilised soil with and without inoculation, and, consequently, with and without nodules. He made a parallel experiment with lupines grown in an unsterilised poor soil, consisting almost entirely of sand dug out from several feet below the surface of the ground, and almost destitute of organisms. They were treated with the non-nitrogenous solution as the others, but the surface of the soil in the pots was left exposed to the air. He inoculated one-half of the pots with a few grams of lupine soil, and left the other half uninoculated. In the inoculated half the roots of the plant were well grown with nodules. On the uninoculated half, only a few imperfectly developed nodules appeared in several of the pots. He selected ten plants from each division, viz. ten plants with nodules, and ten plants without, but otherwise well grown, and analysed them, with the result that there was almost no difference in the amount of nitrogen the two lots had assimilated from the air. As it happened, the un- inoculated lot that had no nodules assimilated rather more than the other. The quantities were— Without nodules . 2°126 grams nitrogen. With nodules. <; 2:09 ”» ”» oe eee ee Noy. 1897. ] BOTANICAL SOCIETY OF EDINBURGH 83 These quantities are more than ten times as great as that assimilated by the plants grown in the sterilised and un- inoculated soil. The result of this experiment is to show that inoculation is of use in a sterilised soil protected from air-borne organisms. In that case the inoculation and the nodulation resulting therefrom increased the nitrogen assimilation eightfold, but, in the case of an unsterilised and unprotected soil, inoculation and consequent nodulation made no difference whatever. The explanation of this unexpected result is that the soil of the unsterilised pots was thickly grown with alge, and well supplied with bacteria; and it is to the activity and nitrogen-assimilating power of these that the plants owed their increased assimilation. In other words, the plants received their nitrogen from the soil, and that nitrogen was brought into the soil from the air by the alge and bacteria which flourished there. If this be the true explanation, it does away entirely with the symbiotic relation supposed to exist between the Leguminosz and the bacteria contained within the nodules. We are still left with the fact that nodulation is due to the interference of bacteria, and that the nodules are highly nitrogenous bodies whose nitrogen, however, is entirely derived from the plant, and utilised eventually by it for the growth of its own seed, should the plant ever arrive at the seeding stage. If that is all, the attack of the bacteria on the roots, and its subsequent lodgment there in the form of a nodule, must be regarded as pure parasitism, and that the plant eventually absorbs the organic matter of the parasite in its mature stage is due to its having sufficient vigour to confine the parasite within a nodule, and so to limit the sphere of its mischief. Whether, in the event of the plant’s not possessing that vigour, the bacteria would get the upper hand of it and kill it down, is a probability that has been suggested, but of which I have no proof. It is evident, however, that such a condition of matters may occur, and it may, upon further investigation, shed some light on the mysterious disease of clover sickness, and of some other apparently parasitic disease to which some leguminous crops are liable. 84 TRANSACTIONS AND PROCEEDINGS OF THE [ Sess. LXIt. It may be objected to the results of Stocklasa’s experiment that they do not explain why it is that leguminous plants should be the only ones able to derive benefit from the nitrogen brought to the soil by the alge and bacteria referred to. That question Stocklasa answers in a some- what unexpected manner. He gives the result of five years experimenting with buckwheat (Polygonum fagoyprum), a plant far removed from the Leguminose, and shows that it also has the power of assimilating atmospheric nitrogen, especially when grown in soils that are fairly well supplied with nitrogenous manure. Into the details of that experiment time will not permit one to enter, but the results are shortly as follows :— 100 plants grown in a sterilised soil assimilated of atmospheric nitrogen : : : .° 1188 grams. 100 plants in an wnsterilised soil . : : Pre sol RORY, (That is to say ten times as much.) 100 plants grown in a sterilised soil to which ammonium nitrate was added asa manure 3°385_,, 100 plants in an wnsterilised soil similarly manured . ; : é ; : . 76709 a This experiment, besides putting on record the fact that plants other than leguminous ones can utilise atmospheric nitrogen, shows how greatly dependent for that faculty they are upon the lowly organisms that inhabit the soil in which their roots are ramifying. Time will permit me to do no more than refer in a few words to an experiment, which, through the kindness of Professor Balfour, and with the valuable assistance of Mr. Harrow, I was able to carry out at the Botanic Garden last summer. The experiment was only a provisional and tentative one, as a prelude to one which I hope to try next summer. A soil made of a very poor subsoil, about three feet below the surface, which had been laid bare during the building improvements going on in the Garden, was chosen on account of its poverty in nitrogen, and it was mixed with sand in equal amount. To this was added a supply of fertilisers, viz. phosphate and potash salts, but no nitrogen. This was filled into three sets of pots, measuring eight inches across, and containing about five pounds of soil each. One-third of the pots was left without further manure, and the other Giabis A04% + = Se ee ee er Noy. 1897.] | BOTANICAL SOCIETY OF. EDINBURGH 85 two-thirds were supplied with nitrogenous manure, one- half with sulphate of ammonia, and the other with flesh meal, and these in varying quantities. Half of these were sterilised by exposure for some time to steam at the boiling- point of water. Moreover, a duplicate of the whole series was made, to which was added nitragin, a supply of which I got from the manufactory in Germany, of the kind specially prepared for application to the bean crop, in the manner described in Mr. MacDougall’s paper, read before the Society last session. This was dissolved in water in the manner recommended by the vendors, and applied to the crop after the leaves appeared above the soil. The sterilised pots were protected with wadding for some time, but its use was discontinued when the seed began to germinate. They were watered with sterilised water. Five beans were planted in each pot, and all were sterilised by dipping in a solution of corrosive sublimate of 1 to 4000 before planting, both in the sterilised and unsterilised section. The pots were accommodated in a cold frame when the experiment began in July, and kept there tll October, when it ended. - The experiment was only a preliminary one, carried on chiefly to enable one to gain some experience, so that a quantitative record of the result was not made. It was found that the plants that throve best were those that had no nitrogenous manure given them. There was a large number of blanks, and in very few pots did all the five beans come up. The division that got no nitrogenous manure was a fairly even one. The plants that did grow were healthy, and most of them were in full flower when the experiment ended. There did not seem to be much difference between the sterilised and unsterilised sets, nor was there any perceptible difference between the pots that were inoculated with nitragin and those that were not. A fairly representative collection was made of the plants in each set. They were carefully turned out of the pots and put into water, so that the earth might fall away from the roots without injury of any kind. I preserved a number of the roots in formation, and removed the stalks. A number of them are shown on the table before you. Four are from sterilised pots, and four from unsterilised ones. . Upon the 86 TRANSACTIONS AND PROCEEDINGS OF THE [Szss. uxm. whole, I am of opinion that the plants grown in sterilised earth rooted the best. The steaming of the soil may have had the effect of making nutritive substances more easily assimilable, but the difference was not great. As regards the application of nitragin, from which so much was expected, it does not seem to have had any effect whatever either upon the growth of the plant, the develop- ment of the root, or the occurrence on these of nodules. Some of the plants that were inoculated with nitragin had nodules upon their roots, and some had none, but the nodules on the nitragined roots were no more numerous nor were they any better developed than those on the set that got no nitragin. This is a disappointing result, but it is similar to that recorded by Professor Somerville in the paper he laid before the Society last session. In searching for the cause of the failure of this much-advertised material, there are various circumstances that may be considered. The bean is not quite so sensitive to inoculation as some other members of the Leguminosee, and Frank describes an experiment with Phaseolus vulgaris in a somewhat similar soil, where nitragin had no effect in increasing the crop whatever, and where, indeed, the plants that were un- sterilised and uninoculated throve best and gained most nitrogen. Frank thought the failure was due to the soil being too poor in organic matter, but if that were so, it was a fatal objection to the use of nitragin, whose chief use and whose greatest virtue was considered to be its capability of enabling leguminous plants to grow on soils poorly supplied with organic matter, and at the bottom of the scale as regards richness in nitrogen. The whole system of growing legumin- ous crops for manurial purposes is to enrich the soil with organic matter, and especially with nitrogen from the air. Soils rich in organic matter are just those that do not require to be treated in that way. Again, perhaps the benefit of nitragin was not felt sufficiently because the plants were cut down before maturity, but if that is so, it again tends to nullify the benefits derived from leguminous plants that are grown for green manuring and for increasing the store of nitrogen in the soil, for green manure vrops are ploughed up long before they ripen. Jeet eee De ee re Dec. 1897.] | BOTANICAL SOCIETY OF EDINBURGH 87 Again, it may be that the whole experiment was too late in the season, or it may be that the soil was otherwise unsuitable, or it may be that the nitragin had lost its vitality, or it may be that it does not possess some or any of the virtues ascribed to it. I hope, during the coming season, to be able to say which of the many hypothesis that may be started are of any importance, for I hope to be able to anticipate every possible objection that a believer in the value of nitragin might be expected to raise. MEASUREMENT OF THE GIRTH OF CONIFEROUS TREES AT BRAEMAR IN 1894. By R. Turnsutt, BSc, and PeRcIVAL C. WaITE. (With Plate.) (Read 9th December 1897.) During April 1894 we spent a fortnight at Braemar, and had many opportunities of observing the destruction caused by the great November gale of 1893. Every wood and forest in the neighbourhood had suffered, and the foresters had been busy during the winter sawing the blown trees into logs. We determined to measure the radii and annual increment of diameter of specimens of Scots pine, Norway spruce, and common larch, so as to be able to calculate the annual increment of girth. Those trees had all, with one exception, grown on the slopes of steep hills, and it was found that the side of the tree which was most obscured by the hill or other trees presented the smallest radius, while the longest radius was turned towards the greatest light. Thus we found the greatest radii on the N., E. and S. sides respectively, in trees with an open aspect in those directions. In none of our specimens did we find the greatest radius to the W., but this may be merely an accidental occurrence, and one to which at present we can attach no importance. It is a law in plant-growth that leaves and the young aerial parts of plants turn towards the light. This pheno- 88 TRANSACTIONS AND PROCEEDINGS OF THE [Szss. uxt. menon must not be mistaken for the bending of trees on exposed situations by the prevailing winds. | On the edges of dense woods and forests, trees have most branches on the side turned to the light; fewest on the side next the mass of the forest. These conditions hold good for the specimens under consideration, therefore we find the greatest development of branches on the same side as the greatest radial increment. Now, since the elaborated sap or digested food of the tree is made in the green leaves, it evidently descends the tree mostly by the bast of the side on which it is manu- factured, and thus brings about the radial increment of wood on that side. The breadth of the annual rings showed that most of the trees had reached the limit of most active growth in girth at the ages of 30 to 50 years; but in some cases the growth was continued long beyond this age, with only a very gradual decrease of vigour. Among the broad annual rings in the older parts of the tree much narrower rings were occasionally found; in the same way, broad rings occasionally among the narrower rings of the younger wood. It is almost impossible to determine definitely the causes which bring about such variations from year to year. In the absence of a detailed history of each tree, the question of thinnings must be left out of account, although it is well known that a judicious thinning affects most beneficially those trees that are thus more exposed to the light and heat of the sun. The trees in question, to all appearance, had grown with plenty of space all round, and had not been forced into the pole-stage, according to the principles of modern sylviculture. Again, the frequency of the variations, above referred to, shows that periodic thinnings could not be the sole cause. | Soil and situation were constant factors throughout, except that, as growth in height proceeded, an increasing density of leafy canopy would be the result, but this would not account for the variation. | , Frequent storms might, by removing certain trees, expose the survivors to greater light, but storms of this Pon itd Dec, 1897.] | BOTANICAL SOCIETY OF. EDINBURGH - 89 nature become historic, and do not occur often enough to account for the variation. Other meteorological conditions, however, must be taken into account, since they form some of the factors which determine the growth of all plants; these are temperature, moisture, and sunshine. The relationship of these factors to the annual increment of girth will form the subject of a second paper. The following were our methods of examining each tree :—After choosing an evenly-sawn section close to the eround, we: found its orientation by means of a pocket compass, then cut two smooth tracks on the surface with a wood chisel so as to get N. and 8, and E. and W. diameters, each passing through the pith. The total lengths of each diameter, and each radius, were measured by us in turn, while the other noted the measurements on paper; then the breadth of each annual ring was taken with a steel millimetre measure, and these measurements were checked at every tenth year. It must be understood that the measurements were made of the wood only, and did not extend beyond the cambium. When the annual rings of the first few or the last years of a tree were too close for accurate individual measure- ment, a collective number was measured, Specimen A was thus measured collectively for the first 6 years; B for the first 5; D for the last 30; £, F, and G had every annual ring measured along each of the four radii; H had a few collective measurements taken between the ages of 25 and 50 years. The sections were immediately above the ground-level, except—D, 12 feet above ground; F, 32 feet above ground ; and H, 34 feet above ground. It would have been better to have got sections 4 or 5 feet above ground, so as to be away from the buttressed part of the trunks near the roots; but we had no choice, since we had to examine the sections as we found them. | In calculating the girth for any one year, the increments of the four radii of that year are added to the sum of the radii of all the preceding years; the total is divided by 2 90 TRANSACTIONS AND PROCEEDINGS OF THE [Szss, xxi. to get the average diameter, and the quotient multiplied by 34 to get the girth for the year. The continued increase in the four radii, the average diameter and the girth for each year, are represented by curves, where the co-ordinates are years, for the age of the tree, z.c. horizontal co-ordinate or abscissa; and milli- metres for the girth, 7.e. vertical co-ordinate or ordinate. The actual scale on the diagrams shown is 5 years to one inch horizontally, and 100 mm. to one inch vertically. The curves for the four radii, average diameter, and girth of each tree are represented for periods of 5 years, and where collective measurements were made an average for each quinquennial period has been struck. On separate diagrams a life-size section of each tree, calculated from the four radii, and marked with rings every 10 years and at the cambium, has been drawn ; and on these sheets, also, has been drawn a section of the ground showing its gradient and the position of the tree. The following are the details of the specimens exam- ined :— A. Common larch (Larix europea, DC.) was situated at the N. side of the Inverey road, and close to its edge, about two miles to the west of Braemar, near the point where the road runs to the S.S.W., so that the 8, and W. sides would receive most light. Immediately above were the lower slopes of Morrone, which rises to a height of 2819 feet, and the tree itself stood about 1200 feet above sea-level. The ground sloped gently at first, and then precipitously to the Dee on the N., the river being within a stonethrow of the tree. Trees grew all round, and the only open ground was towards the road, while from the slope of the ground there was more light on the N. than on the E, side. The S. radius measured 324 mm. » We , i 296 ? N. ” ” 239 ” » Ey F 220 As shown by the curve for the increment of girth, the growth for the first 6 years was slow, then came rapid growth up to 15 years, and a still more rapid growth up to Dec. 1897.] | BOTANICAL SOCIETY OF EDINBURGH 91 35 years, after which the gradient becomes less, and after 50 years of age there is a considerable falling off, with a slight increase, however, during the last 6 years. The last increase in the gradient should be specially noted, as it occurs in all the trees examined, but it will be discussed in the second paper. The girth increase was most vigorous from 20 to 35 years of age, but good, sound growth was made up to 50 years of age. The tree was 66 years old, and the total girth of wood was 1695 mm., we. 5 feet 74 inches. B. Norway spruce (Picea excelsa, Link.) grew about a furlong W. of A, on the same side of the road, but much farther down the hill. It had trees all round, and the only open aspect was to the N., where the ground sloped very rapidly down to the Dee. The N. radius measured 201°5 mm. ” S. »” ” 186°5 2? ” WwW. ” »” 178°5 2? E. ” ” 175-0 2? The girth curve shows at once that the conditions had been less favourable for the spruce than the larch, The first 5 years’ growth was slow, then came a more rapid and almost uniform growth up to 30 years of age, after which the gradient becomes smaller and smaller until 60 years of age, from which time until the tree was levelled, at the age of 68, there was a shght rise. The total girth of wood was 1165 mm., ze. 3 feet 102 inches. C. Scots pine (Pinus sylvestris, L.) grew on the N.E. slope of Craig Choinnich, a very steep wooded hill which rises about a mile to the east of Braemar into a sharp peak, 1764 feet above sea-level. Below the place where this tree grew, the public road to Ballater, distant only a few yards, runs in an E.S.E. direction. Trees grow down to the road, while close to the latter, on the N. side, is the Dee, and beyond the river lie open meadows. The open aspect was thus on the N.E. side of the tree, and it is noteworthy that the N.E. radius was 319 mm. long, but this radius is not taken into account in calculating the girth, as uniformity was desired in all the calculations. © bo TRANSACTIONS AND PROCEEDINGS OF. THE [Szss. LXII. The E. radius measured 291 mm. ” N. PP) ” 252 ” » W. ” ”? 252 ” ” S. » »” 215°5 ” The S. side of the tree was obscured by the hill and the trees above. The curve of girth shows slow oa up. to 5 years, rapid growth up to 20, and less rapid up to 85, after which the gradient becomes less steep. The tree reached the age of 116 years, ma ‘its girth measured 1588 mm., zc. 5 feet 34 inches at the cambium. D. Norway spruce (Picea excelsa, Link.) grew quite close to C, but differed from all the preceding in being cut 12 feet above ground. Like C, its E. radius is greater than any of the eee three. The E. radius measured 298° 5 mm. ” N. ” » 229° 0 ” ” S. ” ” 1x ore 05 wp) Wastent 33 » 1585, The girth curve shows a good and fairly uniform growth up to 50 years of age, but it must be remembered in this case that, to allow for the 12 feet above the ground, we must add 15 or more years to the age of the section to obtain the actual age of the tree. In all probability it was planted at the same time as its neighbour C, the Scots pine. According to our measurement the age of the section was exactly 100 years, and its girth of wood was 1314 mm., or 4 feet 44 inches. EL. Scots pine (Pinus sylvestris, L.) grew on the same slope of Craig Choinnich as C and D, but some distance to the W. of the latter, near the edge of the wood, and almost opposite Braemar Castle. This change of position removed the tree from the close shadow of the hill, and opened up the 8.W. and W. aspects. Like D, the tree was cut a few feet above the roots, but, unfortunately, the exact height was not recorded. The. 8. radius measured 313°5 mm. aR Sieriyy ‘ 206'L>. gy : 248'02 Bae > gs . 236°0:- 4 Dec. 1897.] BOTANICAL SOCIETY OF EDINBURGH oa The girth curve of the tree is the most uniform of the series, but owing to the height of the section above the ground, the first few years’ growth is wanting. The crown of the girth curve shows the tree to have reached its best between the fortieth and fiftieth years, but even up till the last it retained much of the vigour of its youth. The last five years show a slight increase of gradient. The tree at the section had reached 100 years of age, and measured 1654 mm., or 4 feet 81 inches in girth. F. Common larch (Larix europwa, DC.) grew on the S.E. slope of Carn-na-Drochaide, about half a mile S.W. of Inverchandlick Cottage, on the N. bank of the Dee. The slope was gentle, the tree grew several yards back from the road which opens the aspect to the N. and E., but it is difficult to obtain the exact surroundings of the tree at the level of the section, which was 32 feet above ground. The tree grew about 1060 feet above sea-level. The N. radius measured 135°5 mm. ” E. ” ” 134:0 oF) ” S. ” ” 115°5 ” » WW: ” ” 1 1 10) >? Since the section was taken 32 feet above ground, one must add about forty or fifty years to the ascertained age to get the age of the tree. The age of the tree at the section was 74 years, and the girth 779 mm., ic. 2 feet 74 inches. G. Common larch (Lariz europea, DC.) grew on level ground about half a mile N. of Braemar, among a clump of trees to the N.W. of the cemetery, and near the old toll-bar which stands at the junction of the main road with that which leads to the ferry over the Dee. An old gravel pit lay immediately to the N. and E. of this tree, while the S. and W. sides were shaded by other trees. The whole trunk was lying on the ground, and we found it to be 54 feet high, while the section was measured at the ground level. The N. radius measured 257 mm. ” E. »? » 200 ” » We: » » 1 73 ” eS ae ee as ka 165 94 TRANSACTIONS AND PROCEEDINGS OF THE [ Sess. LXIl. The growth was fair up to 10 years of age, much quicker up to 20, somewhat slower up to 30, and then considerably slower up to 64, the age of the tree. The girth at the stool measured 1249 mm., or 4 feet 2 inches. H, Common larch (Lariz ewropwa, DC.) grew beside F, on the N. side of the Dee, and the section was taken 34 feet above the ground. As in the case of F, it is difficult to learn the conditions of light and shade of this tree. The E. radius measured 91°5 mm. >? S. bP) ”? 86:0 » bb) W. »> ” 79°0 ? Lo TN AHR, 3) own, The curve is of the same nature as that in F, but the growth had been slower. The tree at the section was 70 years old, and measured only 527 mm., or 1 foot 9 inches in girth. The diagrams referred to in the text were used to illustrate the reading of the paper; the only one repro- duced here is that showing the curves of annual girth- increment. THE DIAMETER-INCREMENT OF THE WOOD OF CONIFEROUS TREES AT BRAEMAR IN RELATION TO CLIMATIC CONDITIONS. By R. TurRNBULL, B.Sc. (With Plate.) (Read 13th January 1898.) The first part of this paper, read at the December meeting of the Society, dealt with the measurements of the radii, average diameters, and girths of the wood of coniferous trees which were blown down near Braemar by the November gale of 1893. Curves of the continued increase of diameter and girth were drawn for each tree, so as to show the increase in > relation to age, and since the paper was read, curves for the increase of area have been added. There were eight sections examined, including larch, Scots pine, and Norway spruce, and in every case the Jan. 1898.] | BOTANICAL SOCIETY OF EDINBURGH 95 largest radius was found to be on the side exposed to the greatest light. The present paper is an attempt to find a relationship between the annual diameter-increment and the climatic or meteorological conditions. A better plan would have been to compare the annual area-increment with those conditions, but the additional labour of calculating the areas for each year would have extended the work over another month; by this latter method, however, the average height of the curves would have been maintained : whereas, by using the diameters only, the average heights of their curves naturally decrease with time, because, as the girth of the tree expands, the average increment of the diameter decreases. There is very little lost in the method adopted, since girth and area are continuous functions of the diameter. The rise and fall seen in the diameter curves would be seen at the same places in the girth and area curves, only they would be more pronounced in the last two. Of the specimens mentioned in the first paper, only five could be used for the purpose of drawing out continuous curves of the annual diameter-increment, because in these cases the measurement of each annual ring had been taken, while in the three omitted from the present paper measurements had often to be taken of 5 or more years collectively, owing to the smallness of the rings. Meteorological observations have been made at Braemar since 1856—the greater part of the time by Mr. James Aitken, the present observer—at the Observatory founded by H.R.H. the late Prince Consort in 1855; and the observations from 1856 to 1893 were reduced by Mr. R. C. Mossman, F.R.S.E., and recorded in the “ Journal” of the Scot. Met. Society (Vol. x., Third Series, No. x., 1894). From Mr. Mossman’s tables I have calculated means for periods of three and six months respectively, while the tables supplied the yearly means; and curves have been drawn for temperature and rainfall, showing the three- monthly periods, beginning with January of each year. By uniting the second and third periods and taking the averages, the curves for the growing season—April to September inclusive—have been obtained. My object in 96 TRANSACTIONS AND PROCEEDINGS OF THE [Szss. Lam. doing this is to get the direct influence of these conditions while the trees are actually growing. The mean temperature and rainfall for the year do not represent the means for the summer months; at the same time the means for the winter and spring months, and also for the year, have been before me in studying the curves of increment. The relative humidity of the air during the six growing months has been represented by another curve. I am indebted to Dr. Alexander Buchan, Secretary, Scot. Met. Society, for kindly placing at my disposal his MS. tables of sunshine for the whole of Scotland, and from these tables curves have been drawn; these curves, how- ever, are only approximately true for Braemar, but they are a great help to the present investigation, as light is an important factor in the growth of plants. Since the meteorological observations at Braemar began, in 1856, I had to make that year the starting-point for my curves; the period under consideration is, therefore, 38 years. The following are the specimens now under considera- tion: — Specimen A, common larch, 66 years old at section near the ground; on N. slope of hill; S.W. exposure. Specimen £, Norway spruce, 68 years old at section near the ground; on N. slope of hill; N. exposure. These two trees grew about 2 miles west of Braemar, and about 100 feet above the river Dee. Specimen JZ, Scots pine, 100 years old; on N. slope of hill, one mile E. of Braemar, and 20 feet above the Dee; S.W. exposure. Specimen /, common larch, 74 years old, but section at 32 feet above ground, so that tree must have been considerably over 100 years old; 1 mile N. of Braemar, on S.E. slope of hill N. of the Dee; exposure uncertain. Specimen G, common larch, 64 years old at section near the ground; on level alluvial soil, with gravel subsoil, 4 mile N. of Braemar; exposure N.E. From these notes and the first part of the paper it will be seen that conditions and aspects of the trees varied considerably, and these may account for some of the minor differences found in the curves. A more accurate method of investigation would be to CURVES OF ANNUAITP 18-56 57 58 59 6O 61 62 63 64 65 66 67 68 +69) 270 sv 792 73 74 758 [ees eB ae 5 _ 0 -F 4 3-5 3 2-5 ») 85 SO fam lie 52 51 50 : 18-53 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 W2eeo 7] Ve . METER—INCREMENT. ‘ 78 79 so 81 82 8 84 8 86 87 88 89 90 91 92 9 A bby~s ARCH. St as ee So (i C. PINE. See 1200 a ARCH. ee |G. ARCH. | tp Eg ae aes “MIN. TEMP | } OF EACH =— YEAR. RAINFALL | APRIL TO SEPTR. HUMIDITY “A PR-SPTR. ace TEMP. APR-SPTR. 79 80 81 82 83 84 8 86 87 88 89 90 91 92 93 R. TURNBULL, del. Jan. 1898.] | BOTANICAL SOCIETY OF EDINBURGH 97 secure a large number of trees from the same neighbour- hood, and of approximately the same age, so as to compare their curves of increment. While considering the external influences of a plant, one must not overlook the internal conditions. Perennial plants store up the surplus food of one year to be used during the following year, but the balance carried over from one year to another depends largely on the conditions of growth ; consequently the growth of any one year is not wholly dependent on the meteorological conditions of that year, but also on the reserved food materials, which, in turn, are dependent on the meteorological conditions of the preceding year. Again, insect attacks and severe frosts may so injure the buds and leaves of trees during the growing season as to make their effects felt over a period of years. These are some of the difficulties to be met with in trying to account for the rise and fall of the increment curve. Sylvicultural methods have never been adopted where those trees grew. I am assured of this by Mr. John Michie, head forester, Balmoral; the trees were planted and left to nature, consequently thinnings need not be considered. Gales of wind may have levelled trees around the specimens now under consideration; but, although Mr. Aitken in his reports notes the occurrence of gales, he mentions only that of November 1893 as having been destructive to trees. If the curve of larch A be examined, it will be seen to contain six well-marked maxima in 1859, ’70, ’75, ’82, 89, and ’93 respectively, as well as a few other maxima of less importance ; and three deep minima in 1864, ’79, and "92 respectively, and several other depressions. To under- stand these points it must be remembered that larch thrives best in a dry, sunny atmosphere. The maxima of 1859, ’70,’75, and ’82 occurred when the amount of sunshine for the growing season was above the mean. The minima of 1879 and 1892 occurred when the sunshine was very much below the mean. The minimum of 1864 occurred during one of the maximum sunshine periods, and, as this occurrence seems to contradict TRANS. BOT. SOC, EDIN. VOL. XXI. H 98 TRANSACTIONS AND PROCEEDINGS OF THE [Szss. xu. the coincidence of sunshine and increment, it will require to be explained in terms of temperature and moisture. The six maxima agree still more closely with the periods of maximum temperature, as each coincides with the tem- perature at or above the mean. ‘The three minima also occurred when the temperature was considerably below the mean. The 1864 minimum followed the very cold summer of 1863, and in 1864 the temperature was only very slightly above the mean. Let us now follow the curve in detail from 1856 onwards. The rise from 1856 to 1859 took place during continuous warm, dry, sunny, growing seasons. The fall of 1860 came with a very cold, sunless, and moist summer. The season of 1861 was warmer, but the other conditions did not improve, and rainfall and humidity were much above the mean. The cold of 1860 would allow of very little reserve food, while the increased moisture of 1861 would hinder growth, and these two conditions are sufficient to account for the continued fall in 1861. It is difficult to understand the rise of 1862, but the increment for that year is small when compared with the five years preceding 1861, and it may partly be accounted for by the lessened rainfall of 1862, although the tempera- ture was below the mean. The very cold season of 1863, added to the relatively cold season of 1862, brought about a further fall, which was continued until 1864, when the first minimum was reached. The temperature of April, May, and June 1864 fell below the freezing-point, and this may have helped to check the growth. From 1864 to 1870 there was a steady rise, due largely to the increased sunshine, higher temperature, and lessened rainfall of those years, excepting the cloudy, colder, and moister year of 1867, which caused a slight dip in the curve. The temperatures of 1867 and 1868 were not suffi- ciently far below the mean to do more than lower the curve slightly in its upward rise, but in 1869 and 1870, with warmer, sunnier, and drier seasons, the rise was rapid. 9 Pete ae PT Jan. 1898.] | BOTANICAL SOCIETY OF EDINBURGH 99 The second great maximum is thus found in 1870, when all the most favourable conditions of growth for larch occurred. The curve between 1870 and 1875 first falls and then rises with the sunshine and temperature, while the lowest point of this period coincides with the very heavy summer rainfall of 1873, almost equalled by the summer rainfall of 1872. The rise of 1875 marks the third of the great maxima, when the conditions were similar to those of the first maximum in 1859. A decrease of increment took place from 1875 to 1879, during a cold, wet, and cloudy period. There was a rapid rise in 1880, due to a warm, dry, sunny season; a fall in 1881 coinciding with a cold, cloudy summer; and another rise—the fourth maximum—in 1882, when sunshine and temperature were greater than in 1881, and, although the rainfall was greater, the relative humidity was very little above the mean. From 1882 to 1889 there was a fall, and then a rise with the sunshine and temperature. —_ Accessions to Society, 1895-96, iii. Accounts of Society, 1895-96, 1896-97, 1897-98, 1898-99, v., xi., xix., Xxxi. Ecidium Urtice exhibited, vii. Agaricus melleus exhibited, xxxiv. Aitchison, Dr. J. E. T., Death of, | xXx Obituary Notice of, 224. Aitken, Dr. A. P. Presidential Address, 1896, 1. Presidential Address, 1897, 65. Nitrogenous Food of Plants, 1. Relation between the Colour of Daffodils and the Composition of the Soil, 113. Exhibits Abormal Apple, iv. Symbiosis, 65. Allman, Dr. J. C., Death of, xx. Alpine Botanical Club, Scottish, Ex- cursion to-Clova, 1896, 40. to Killin, 1897, 104. -——— to Kirkby Lonsdale, 1899, 270. Anacharis alsinastrum exhibited. xx. Andromeda hypnoides exhibired, Andromeda polifolia, Notes on, 144. Additional Notes on, 258. Toxic Properties of, 258. Apodya lactea, Cornu, 109. Arran, Carex limosa from, exhibited, Pyrus Aria and its Varieties in, + 56. Arrow Poisons exhibited, xxi. Artemisia stelleriana, Boss., in Scot- land, 307. 7 ei rubescens, Bref., in Scotland, 217. Astragalus alpinus, var. albus, 117. Bacteria of the Soil, 25. Bainbridge, A. F. Fellow, vi. Baker, J. G. Elected Brit. Fellow, ii- Bailey, Colonel F., Exhibitions by, ii. Barentz Sea, Plants from Hope Island in, 166. Bell, J. Montgomerie. Notes ona Visit to the Dovrefjeld, Norway, 281. Betulin, Preparations of, exhibited, XXxii. Bipalium Kewense exhibited, vi. Birch Bark, Preparations of, - hibited, xxxii. Black, W. G., exhibits Photographs, XXXV. ine, Microphotographs of, ex- hibited, xxxv. TRANS. BOT. SOC. EDIN. VOL. XXI- Hon. ex- Borthwick, A. W. Elected Res. Fellow, xxi. On Interfoliar Buds in Pines, 154. On Quadrifoliar Spurs in Pinus Laricio, 150. On Witches’ Brooms on Pinus Sylvestris, 196. _ Bostrichus dispar, Acer attacked by, Elected Res. | exhibited, vii. Botanic Garden, Notes from (Title only), iv., vi.. vii., Vili. Boyd, W., exhibits Poa Suecica, ¥Xv- Buchan-Hepburn, Sir Alex., exhibits Oncidium Phymatocheilum, viii. Cabbage. Skeleton of Stem hibited, vii. Caffeine, Preparations of, exhibited, Xxxxiy. Callidium bajulum. Wood damaged by, exhibited, vii. Campbell, J., Exhibitions by, iii. Death of, vii. Carex limosa exhibited, xxxii. Carex Megalanica exhibited, xxxii. Carices, Microphotographs of, ex- hibited, xxxv. Cedrus Atlantica, A deciduous (Title only), XXxv. Clova, Excursion of Scottish Alpine Botanical Club to, 40. Comparison of Plants with Animals (Title only), xii. Coniferous Trees, Measurement of Girth of, 87. Cordyceps Militaris exhibited, xiii. Cossus ligniperda, Poplar attacked by, exhibited, xxxiv. Cowan, Alex. Elected Res Fellow, XXXIV. Cowslip and Primrose Hybrids ex- hibited, vii. Craig, Dr. Wm. Excursion of Scottish Alpine Botanical Club to Clova, 40. Excursion of Scottish Alpine Botanical Club to Killin, 104. Excursion of Scottish Alpine Botanical Club to Kirkby Lonsdale, 270. ex- Crawford, F.C. Elected Res. Fellow, viii. Signs Laws of the Society, xii. Exhibits Carex limosa, XxXil. Exhibits Microphotographs of Stems, XXXv. Exhibits Plants from Kirkby Lonsdale, x xxiii. Exhibits Primula farinosa, xx. 2C yr ol Crinum Macowani, Baker, 211, Croall, A., Alpine Plants collected by, exhibited, xiv. Cuscuta Epithymum exhibited, xv. Daffodils, Colour of, with relation to | Composition of the Soil, 113. Development of Sporophyte, 298. Diatoms presented, ii. Dovrefjeld, Notes on a Visit to, 281. Drosera Tentacles, Nuclei and Cell Plaswa in (Title only), xxii. Druce, G. Claridge. Artemisia steller- iana, 307. Dunn, Malcolm, Exhibits by, xiv., xXxxiii. Obituary Notice of, 220. Elder growing on an Apple (Title only), XXXv. Election of Officers, 1896-97, 1897-98, 1898-99, 1899-1900, i., ix., xvii., XxXiX. Elliott, Robert, Death of, iii. Engadine, Upper, Botanical Notes on, 198. Ericacexw, Toxic Properties of, 258. Eucalyptus _citriodora exhibited, XXXvi. jicifolia exhibited, xxxvi. sp. exhibited, xxxvi. Euphorbia Myrsinites exhibited, xxv. Flora of West Inverness, Notes on the, 173. Forfarshire, Pyrola uniflora in, viii. Fossil Woods, Histology of, 50, 191. Fungi, Drawings of, exhibited, xxiv. Fungi, Method of Mounting, 159. Fusion of Nuclei among Plants, 132, Geaster, SpecieS exhibited, xxxiii Gentiana nivalis, L., in Sutherland, 217. Geranium sylvaticum, var. album, ex- hibited, xxxvi. Germination of Crinum Macowani, 211. Winter Buds of Hydrocharis Morsus-Rane, 318. Girth of Coniferous Trees, Measure- ment of, 87. Gleichenias, Notes on, 62. Goat Moth exhibited, xxxiv Goes tigrina exhibited, xxi. Grieve, J. Notes on Hybrid Violas, 116. Grieve, Symington. Andromeda poli- folia, 144. — Additional Notes on Andromeda polifolia, 258. Exhibits Pine Shoots attacked by Helobius abietis and Phyllobius argentea, Viii. Groom, Percy, M.A., F.L.8. On the Fusion of Nuclei in Plants, 132. Gunn, Rev. G, A Tour in the Upper Engadine and South-East Tyrol, 198. | Obituary Notice of, 277. Habenaria bifolia, Fasciated, ex- hibited, viii. Hall, C. E. Notes on Tree Measure- ments. Part II., 243. Helobius abietis, Pine Shoots attacked by, exhibited, viii. INDEX Herbarium of Alpine Plants ex- hibited, xiv. Hierochloe borealis, from Kirkeud- brightshire, exhibited, xxvi. Hill, J. Rutherford, exhibits— Arrow and Ordeal Poisons, xxi, Caffeine, xxxiv. Orange, Double, xxii. Taraxacum, Root abnormal, xxii. Tillandsia sp., iv. Winter Buds of Anacharis, xx. Obituary Notice of Dr, J. E. T. Aitchison, 224. Hope Island, First Record of Plants from, 166. . Hormiscium pithyophyllum exhibited, XXV. Huie, Miss L. H. Changes in the Nucleus of Secreting Cells (Title only), xiii, Relation between the Cell Plasm and Nucleus in Drosera (Title only), xxii. Hybrids between Cowslip and Prim- rose exhibited, vii. Hybrid Veronica, 118. Hybrid Violas, Notes on, 116. Hydrocharis Morsus-Rane, Buds of, 318. Hylesinus crenatus, Ash damaged by, exhibited, vii. Injection-staining of Vascular Sys- tem, 54, Inverness, Flora of West, 173. Ivy, Climbing Roots of (Title only), XXXV. Killin, Scottish Alpine Botanical Club visits, 104, Kirkby Lonsdale, Scottish Alpine Botanical Club visits, 270. Plants from, exhibited, xxxiii. Kirkcudbrightshire, Hierochloe borealis in, xxvi. Landsborough, Rev. D. Pyrus Aria and its Varieties in Arran, 56. Leitch, Dr. J., Death of, iv. Lenticels of Solanum Dulcamara, 341. Leptomitus lacteus, 109. Liddesdale, Andromeda polifolia in, 144, Lindsay, R., exhibits— Andromeda hypnoides, ¥Xxiii, Hybrid Veronica, 118. Primulas, XXxXv. —— On Astragalus alpinus albus, Ady, Winter Obituary Notice of Malcolm Dunn, 220. Linton, West, Primula farinosa at, XxX. Lowe, Dr. J. M., F.R.S.E. Gentiana nivalis iu Sutherlandshire, 217. Lundie, A. Micro-Methods, Notes on, 159. Lycopodium clavatum, Variations in, 290. M‘Conachie, Rev. G. Mosses, Ferns, and Lichens of Rerrick, 168. _Exhibits Hierochloe borealis, XXvi. SE Vr i. INDEX MacDougal, Dr. R.S., Soil Bacteria, 25. | Exhibits damage due to— Bostrichus dispar, vii. Callidium bajalum, vii. Cossus ligniperda, Xxxiv. Goes tigrina, xxi. Hylesinus crenatus, vii. Phyllopertha horticola, xxi Scolytus Ratzeburgii, xxi. Exhibits Galls_ of resinella, XXXiv. Exhibits Bipalium Kewense, vi. Exhibits Locusts, vii. M‘Vicar, Symers M. Elected Non- Res. Fellow, vii. Flora of West Inverness, 173. Retinia Madden, Miss, exhibits cidium Urtice, vii. Exhibits Seeds from North Queensland, iv. Mahalanobis, 8S. C. Fellow, iii. Mehnert’s Principle of ‘‘Time Dis- placement,” 298. Melanogaster ambiguus XXXvi. Micro-Methods, Notes on, 159. Miller, J. S., exhibits Pyrola uni- flora, viii. Milne, Alex., exhibits Euphorbia Myrsinites, xxv. Morton, Alex. Elected Res. Fellow, Elected Res. exhibited, xxi. Mucilaginous Plants, Stain for, 159. Murray, A., exhibits Melanogaster ambiguus, XXxvi. Nasturtium officinale, Abnormal | Flower of, exhibited xxvi. Nitragin, Experiments with, 20. Nitrogenous Food of Plants, 1. Norman, F. M. Climbing Roots of | | Red Bay, Flora of, 354, Ivy (Title only), XXXV. Cedrus Atlantica (Title only) XXXV. Elder growing on an Apple (Title only), xxxv. Norway, Notes on a Visit to, 281. Nuclei, Fusion of, 132. Nuclei of Secreting Cells, Changes in (Title only), xiii. Nucleus and Cell Plasm, Relation between (Title only), xxii Obituary Notices— Dr. J. E. T. Aitchison, 224. Malcolm Dunn, 220. Rev. George Gunn, 277. Dr. G. C. Wallich, 222. Officers of the Society 1896-97, 1897-98, 1898-99, 1899-1900, i, ix, xvii, xxix. Oncidium Phymatocheilum exhibited, viii. Orange, Double, exhibited, xxii. Orrock Miss R. Elected Res. Fellow, xiii. — Exhibits Cordyceps Militaris, — Exhibits Eucalyptus sp., XXxvi. Paintings of Swiss Flowers, xxii. xiii. Exhibits Cuscuta Epithymum, | 379 Pantling, Mr. Elected Associate, xv. Paul, Rev. Dr. D. Obituary Notice of Rev. George Gunn, 277. Exhibits Carex limosa, xxxii. Exhibits Drawings of Fungi, XXxiy. Exhibits Species of Geaster, Xxxiii. Pearson, Miss, exhibits Paintings of Flowers, xxii. Phoma pithya, Douglas Fir infected by, xiv. Photochemical Stain for Mucilaginous Plants, 159. Photomicrography of Opaque Sections, tt Phyllobius argentea, Pine attacked , Vill. Phylloperthahorticola, Apples attacked by, xxi. Pines, Interfoliar Buds in, 154, Pinus Laricio, Development of the Quadrifoliar Spurs in, 150. — Sylvestris, Witches’ Brooms on, Plague, Dr. Watson on the, 233. Pleurotus Serotinus exhibited, xxxii. Poa Suecica exhibited, xxv. Potentillew, Noteson. I. The Flower, 329. Potts, G. H., exhibits Saxifrages, vii. Presidential Addresses— Dr. A. P. Aitken, 1896-97, 1-65. Dr. Watson, 1898-99, 121-233. Primulas exhibited, xxxy. Primula farinosa from West Linton, xx. Pyrobetulin, Preparation of, xxxii. Pyrola uniflora in Forfarshire, viii. Pyrus Aria and its Varieties in Arran, 56. Queensland, North, Seeds from, iv. Rerrick, Ferns, Mosses, and Lichens of, 168 Retinia resinella, Galls of, exhibited, Xxxiv. Robertson, R. A. Spirogyra, 185. Contact Negatives for compari- tive Study of Woods, 162. The Flower of the Potentillex, Fossil Woods. Part I., 50. Fossil Woods. Part II., 191. Lycopodium clavatum, Varieties in, 290. On Mehnert’s Principle of **Time Displacements,” 298. Photomicrography of Opaque Sections, 44. Preliminary Note on Witches’ Brooms, 313. Exhibits Eucalyptus citriodora, XXxvi. Exhibits Eucalyptus ficifolia, XXxvi. Roots, Adventitions in Dulcamara, 341. | Roxburghshire, Carex limosa from, Xxxii. Conjugation in- 329. some Solanum 380 Russell, D. Elected Res, Fellow, Scolytus Ratzeburgii; by, exhibited, xxi. XV. Scotland, Artemisia stelleriana in, 307. | Ascoidea rubescens in, 217. Scott-Elliot, Prof. G. F., exhibits— Hormiscium pithyophyllum, xxv. Mosses and Fungi, 218. Herbarium of Spanish Plants, 218. Selkirkshire, Poa Suecica in, xxy. Soil Bacteria, 25. Soil, Composition of, with Relation to Colour of Daffodils, 113, Solanum Dulcamara, Lenticels of, 341. Somerville, Alex., exhibits Goat Moth, XXXIV. Exhibits Carex limosa, xxxii. Presents Chart of Watsonian vice-Counties, xxxii, Sommerville, Prof. Wm. On Nitragin, 20. Spirogyra, Abnormal Conjugation of, 185 Spitsbergen, Flora of, 354. Sprague, Miss, exhibits Plants from Norway, xxxiii, Stabler, G., exhibits Habenaria bifolia, viii. Stem Sections, Photomicrography of Opaque, 44, Stuart, Dr., exhibits Geraniwn sylvaticum, var. album, Xxxvi. Sutherlandshire, Gentiana nivalis in, milite Fasciated Taraxacum, Abnormal Root of, exhibited, xxii. Terras, J. A. Ascoidea rubescens, 217. Adventitious Roots and Lenti- cels of Solanwm, 341. Germination of Winter Buds of Hydrocharis, 518. Xerophytic Adaptations (Title only), iv. Traill, W. G., presents Diatoms, ii. Death of, vii. Tree Measurements, Notes on, 243. Tree Roots from Drain exhibited, ii. Tremellodon gelatinosum exhibited, xxi, Birch attacked | INDEX Turnbull, Robert, Apodyalactea, 109, Diameter - increment in the Wood of Coniferous Trees, 94, Flora of Spitsbergen, 354. Girth of Coniferous Trees, 87, -——— Plants from Hope Island, 166. Exhibits Primrose Hybrids, Vii. Exhibits Nasturtium officinale, XXvi. Exhibits Herbarium of Alpine Plants, xiv. Exhibits Inverted Hyacinth, vi. Tyrol, South-East, Botanical Notes on Tour in, 198, Uruguay, Tree Measurements in, 243. Veronica, Hybrid, 118. Violas, Hybrid, 116. as Percival C. On Gleichenias, Wallich, Dr. G. C., Obituary Notice of, 222, Ward, Professor H. M. Elected Hon. Brit. Fellow, ii. Watson, Dr. W. On the Plague, 233, —_—— Obituary Notice of Dr. Wallich, 222. Presidential Address, 1898, 121. Presidential Address, 1899, 233. Teaching of Darwin. and Pasteur, 121. z - Exhibits Zvremellodon gelatin- osum, XXi. Watsonian vice-Counties, Chart of, presented, xxxii. West Inverness, Flora of, 173. West Linton, Primula farinosa at, xx. Wilson, Dr. J Germination of Crinum, 211. Exhibits Drawings of Fungi, XXiv. Lantern Slides of Fungi, xxiv. Winter Buds of Hydrocharis, 318. Witches’ Broom on Pinus Sylvestris, 196. Witches’ Brooms, Preliminary Note on, 313. Woods, Contact Negatives of, 162. Xerophytic Adaptations, Some (Title only), iv. , f ‘ ; ‘ 4 ie a # ee ‘ ‘ ‘ ’ i“ 4 ) =- * ed st c at Soe re elee ©, , | 7 a! >) 4a “ea i finn i Wwe: «= he - OO Gp BFE. teen ee me ene et age Rar! alal AWAArAnAnna acerca sal | Aral: : AA i ANANS - f\ RAY, a ex! waa mAaRal A IAY, aby Aa