Ex Libris Quos
Anno MCMV Donavit
Accesio N
Annals of Botany
(
EDITED BY
ISAAC BAYLEY BALFOUR, M.A., M.D., F.R.S.
FELLOW OF MAGDALEN COLLEGE, AND SHERARDIAN PROFESSOR OF BOTANY IN THE UNIVERSITY OF OXFORD
SYDNEY HOWARD VINES, D.Sc., F.R.S.
FELLOW OF CHRIST’S COLLEGE, AND READER IN BOTANY IN THE UNIVERSITY OF CAMBRIDGE
AND
WILLIAM GILSON FARLOW, M.D.
PROFESSOR OF CRYPTOGAMIC BOTANY IN HARVARD UNIVERSITY, CAMBRIDGE, MASS., U.S.A.
ASS/S TED BY OTHER BOTANISTS
VOLUME I
With eighteen Plates, in part coloured, and six Woodcuts
London
HENRY FROWDE, AMEN CORNER, E.C.
OXFORD: CLARENDON PRESS DEPOSITORY, 116 HIGH STREET
1887-1888
Oxford
PRINTED AT THE CLARENDON PRESS
EfY HORACE HART, PRINTER TO THE UNIVERSITY
'Q'^rfab
6 1
CONTENTS.
No. I.
PAGE
Marshall Ward, H., and Dunlop, John. — On some points in the Histology and Physiology of the Fruits and Seeds of
Rhamnus. (With Plates I & II) i
Gardiner, W., and Ito, Tokutaro. — On the structure of the mu- cilage secreting cells of Blechnum occidentale, L., and Os- munda regalis, L. (With Plates III & IV) . . . 27
Calvert, Agnes, and Boodle, L. A.- — On laticiferous tissue in the pith of Manihot Glaziovii, and on the presence of Nuclei
in this Tissue. (With Plate V) 55
Gregg, W. H. — Anomalous thickening in the roots of Cycas See-
manni, Al. Braun. (With Plate VI) 63
NOTES.
Oliver, F. W. — Phenomenon analogous to leaf-fail . . . . 71
Vaizey, J. Reynolds. — The transpiration of the Sporophore of
the Musci .......... 73
Blake, J. H. — The prickle-pores of Victoria regia .... 74
Calvert, Agnes. — The laticiferous tissue in the stem of Hevea
brasiliensis 75
Bayley Balfour, Isaac. — ‘ Sporophore ’ and ‘ Sporophyte * . 77
REVIEW.
Lectures on the Physiology of Plants, by Julius v. Sachs. Translated
by H. Marshall Ward 81
RECORD OF CURRENT LITERATURE i-xli
No. II.
Hooker, Sir J. D. — On Hydrothrix, a new genus of Pontederia-
ceae. (With Plate VII) 89
Oliver, F. W. — On the obliteration of the Sieve-tubes in La-
minariae. (With Plates VIII & IX) 95
Treub, Melchior.— Some words on the life-history of Lycopods . 119
Bower, F. O.
On the modes of climbing in the genus Calamus. (With wood-
cuts 1-3) 125
On the limits of the use of the terms Phyllome and Caulome.
A suggestion ......... 133
Vaizey, J. Reynolds. — On the absorption of water, and its relation
to the constitution of the cell- wall in Mosses . . . 147
Morris, D. — On the use of certain plants as Alexipharmics or
Snake-bite antidotes . 153
Robinson, Benjamin L.— Notes on the genus Taphrina . . . 163
NOTES.
Vines, S. H. — Apospory in Characeae 177
Schonland, Selmar.
Method for preserving the colours of Flowers in dried specimens 178 The apical meristem in the roots of Pontederiaceae. (With wood- cuts 4 and 5)
79
IV
Contents.
PAGE
NOTES (continued).
Bower, F. O. — Preliminary note on the formation of Gemmae on
Trichomanes alatum . . . . . . . . 183
Balfour, Isaac Bayley. — ‘ Coco-nut,’ not ‘Cocoa-nut ’ . . 184
NOTICES OF BOOKS,
Die morphologische und chemische Zusammensetzung des Protoplasmas ,
von Dr. Frank Schwarz . . . . . . . 187
Monog ra ph iae Phanerogamertim , Prodromi nunc continuation nunc revisio editoribus et pro parte auctoribus Alph. et Cas. de Can- dolle. Vol. V, Pars II ; Ampelideaen auctore J. E. Planchon 195 BOOKS AND PAMPHLETS RECEIVED 201
Nos. HI & IV.
Woodworth, W. McMichael. — The apical cell of Fucus. (With
Plate X) 203
Johnson, T. — The procarpium and fruit in Gracilaria confervoides,
Grev. (With Plate XI) 213
Green, J. R. — On the germination of the tuber of the Jerusalem Arti- choke (Helianthus tuberosus) . . . . . . 223
Oliver, F. W. — On the sensitive labellum of Masdevallia muscosa,
Rchb. f. (With Plate XII) 237
Bateson, Anna. — The effect of cross-fertilization on inconspicuous
flowers 255
Sanford, Elmer. — Microscopical anatomy of the common Cedar-
Apple (Gymnosporangium Macropus). (With Plate XIII) . 263
Bower, F. O. — On some normal and abnormal developments of the
oophyte in Trichomanes. (With Plates XIV, XV, XVI) . 269
Scott, D. H. — On the floating-roots of Sesbania aculeata, Pers.
(With Plate XVII) . 307
Williamson, W. C. — On some anomalous cells developed within the interior of the vascular and cellular tissues of the fossil plants of the coal measures. (With Plate XVIII) . . 315
Marshall-Ward, H. — Some recent publications bearing on the
question of the sources of nitrogen in plants . . . 325
NOTES.
Clarke, C. B. — On Acalypha indica, Linn. (With woodcut 6) . 359
Thiselton-Dyer, W. T. — Calcareous deposit in Hieronyma alchor-
neoides, Allem 361
Gardiner, W. — On the power of contractility exhibited by the pro- toplasm of certain plant-cells . . . . . . 362
Balfour, Isaac Bayley. — The replum in Cruciferae . . . 367
NOTICES OF BOOKS AND PAPERS.
Ueberdie Cultur flechtenbildender Ascomyceten ohne Algen , von Alfred
Moeller 369
Ueber die Abhdngigkeit der Assimilation griiner Zellen von Hirer Sauer st off at h m u ng, und den Ort, wo der im Assimilationsacte der Pfianzenzelle gebildete Sauerstoff entsteht , von N. Pring- sheim ........... 371
Das pflanzenphysiologische Praktikum, von W. Detmer . . . 375
Einleitung in die Palaophytologie , von H. Grafen zu Solms-Laubach 376
BOOKS AND PAMPHLETS RECEIVED 379
NECROLOGY FOR 1887 381
RECORD OF CURRENT LITERATURE ...... xliii-cx
INDEX.
PAGE
A. ORIGINAL PAPERS AND NOTES.
Balfour, Isaac Bayley.
‘ Sporophore ’ and ‘ Sporophyte ’ . . . , . . -77
‘ Coco-nut,’ not ‘ Cocoa-nut ’ . . . . . . . .184
The replum in Cruciferae . . . . . . . .367
Bateson, Anna. —The effect of cross-fertilization on inconspicuous
flowers 255
Blake, J. H. — The prickle-pores of Victoria regia .... 74
Boodle, L. A. — See Calvert, A 55
Bower, F. O.
On the modes of climbing in the genus Calamus. (With Wood-
cuts 1-3) . . . .12
On the limits of the use of the terms Phyllome and Caulome. A
Preliminary note on the formation of Gemmae on Trichomanes
alatum 183
On some normal and abnormal developments of the oophyte in
Trichomanes. (With Plates XIV, XV, XVI) . . .269
Calvert, Agnes. — The laticiferous tissue in the stem of Plevea
brasiliensis .......... 75
Calvert, Agnes, and Boodle, L. A. — On laticiferous tissue in the pith of Manihot Glaziovii and on the presence of Nuclei in
this tissue, (With Plate V) 55
Clarke, C. B. — On Acalypha indica, Linn. (With woodcut 6) . . 359
Dunlop, John.— See Marshall- Ward 1
Gardiner, W. — On the power of contractility exhibited by the proto- plasm of certain plant-cells 362
Gardiner, W., and Pro, Tokutaro. — On the structure of the mucilage-secreting cells of Blechnum occidentale, L., and Osmunda regalis, L. (With Plates III, IV)' , . . 27
Green, J. R. — On the germination of the tuber of the Jerusalem
Artichoke (Helianthus tuberosus) . . . . . *223
Gregg, W. H. — Anomalous thickening in the roots of Cycas See-
manni, Al. Braun. (With Plate VI) ..... 63
Hart, J. H. — See Thiselton-Dyer .......
Hooker, Sir J. D. — On Hydrothrix, a new genus of Pontederiaceae.
(With Plate VII) 89
Pro, Tokutaro. — See Gardiner, W. 27
Johnson, T. — The procarpium and fruit in Gracilaria confervoides,
Grev. (With Plate XI) 213
Marshall-Ward, IP. — Some recent publications bearing on the
question of the sources of nitrogen in plants . . . .325
VI
Index .
PAGE
Marshall-Ward, H., and Dunlop, John.— On some points in the Histology and Physiology of the Fruits and Seeds of Rham-
nus. (With Plates I. and II) i
Morris, D. — On the use of certain plants as Alexipharmics or Snake- bite antidotes 153
Oliver, F. W.
Phenomenon analogous to leaf-fall . . . . . .71
On the obliteration of the sieve-tubes in Laminarieae. (With Plates
VIII and IX) 95
On the sensitive labellum of Masdevallia muscosa, Rchb. f. (With
Plate XII) 237
Robinson, Benjamin L. — Notes on the genus Taphrina . . . 163
Sanford, Elmer. — Microscopical anatomy of the common Cedar-
Apple (Gymnosporangium Macropus). (With Plate XIII) . . 263
SCHONLAND, SELMAR.
Method for preserving the colours of flowers in dried specimens . 178
The apical meristem in the roots of Pontederiaceae. (With Wood-
cuts 4 and 5) . . 1 79
Scott, D. H. — On the floating-roots of Sesbania aculeata, Pers. (With
Plate XVII) . 307
Thiselton-Dyer, W. T. — Calcareous deposit in Hieronyma alchor-
neoides, Allem 361
Treub, Melchior. — Some words on the life-history of Lycopods . 119
Vaizey, J. Reynolds.
The transpiration of the Sporophore of the Musci . . . *73
On the absorption of water, and its relation to the constitution of the
cell- walls in Mosses 147
Vines, S. H Apospory in Characeae 177
Williamson, W. C. — On some anomalous cells developed within the interior of the vascular and cellular tissues of the fossil plants of the coal measures. (With Plate XVIII) . . . *315
Woodworth, W. McMichael. — The apical cell of Fucus. (With
Plate X) 203
B. LIST OF ILLUSTRATIONS. a. Plates.
I, II. Fruit and seeds of Rhamnus infectorius (Marsh all- Ward and Dunlop).
Ill, IV. Mucilage-secreting cells of Blechnum occidentale, Ceratopteris thalictroides, Blechnum brasiliense, and Osmunda regalis (Gardiner and Ito).
V. Laticiferous Tissue in Manihot Glaziovii (Calvert and Boodle).
VI. Thickening in roots of Cycas Seemanni (Gregg).
VII. Hydrothrix verticillaris, Hook. f. (Sir J. D. Hooker).
VIII, IX. Obliteration of Sieve-tubes in Laminarieae (Oliver).
X. Apical cell of Fucus (Woodworth).
XI. Procarpium and Fruit in Gracilaria confervoides, Grev. (John- son).
XII. On the sensitive Labellum in Masdevallia muscosa, Rchb. f. (Oliver).
Index.
Vll
PAGE
Plates ( continued ).
XIII. Gymnosporangium Macropus (Sanford).
XIV, XV, XVI. Developments of the Oophyte in Trichomanes (Bower).
XVII. Anatomy of the floating-roots of Sesbania aculeata, Pers. (Scott and Wager).
XVIII. Anomalous cells in the interior of fossil plants (Williamson).
b. Woodcuts.
i . Portion of shoot of Calamus, sp. (Bower).
2. Transverse section through a bud of Calamus, sp. (Bower).
3. Longitudinal section through a bud of Calamus, sp. (Bower).
4, 5. Longitudinal sections through apices of roots of Eichhornia azurea, Kunth. (Schonland).
6. Peculiarities in the spike of Acalypha indica (Clarke).
C. BOOKS AND PAPERS NOTICED.
Detmer, W. — Das pflanzenphysiologische Praktikum (F. D.) . . 375
Moeller, Alfred. — Ueber die Cultur flechtenbildender Ascomyceten
ohne Algen (W. G. F.) 369
Planchon, J. E. — Ampelideae in Alph. und Cas. de Candolle’s Mono-
graphiae Phanerogamerum, Vol. V, Pars II. (I. B. B.) . . 195
Pringsheim, N. — Ueber die Abhangigkeit der Assimilation griiner Zellen von ihrer Sauerstoffathmung, und den Ort, wo der im Assimilationsacte der Pflanzenzelle gebildete Sauerstoff entsteht
(S. H. V.) 371
Sachs, Julius von. — Lectures on the Physiology of Plants. (Trans- lated by H. Marshall Ward) 81
Schwarz, Frank. — Die morphologische und chemische Zusammen-
setzung des Protoplasmas (S. H. V.) 187
Solms-Laubach, H. Graf. zu. — Einleitung in die Palaophytologie
(I. B. B.) 376
D. BOOKS AND PAMPHLETS RECEIVED .... 201, 379
E. NECROLOGY FOR 1887.
Areschoug, Johan Ehrhart .
Boot, William ....
Boussingault, Jean Baptiste Caspary, Robert Cienkowski, Leo de Dickson, Alexander Didrichsen, Didrik Ferdinand Eichler, August Wilhelm .
Ferguson, William .
Haast, John Francis Julius von Kellogg, Albert Kickx, Jean Jacques Kosteletzky, Vincenz Franz
383
383
387
395
396
399
400
403
4° 3 4°4 4°4
Index .
viii
PAGE
NECROLOGY FOR 1887 {continued).
Lacoste, Cornelius Marinus van der Sande .... 405
Lees, Edwin 406
Lojka, Hugo 408
Michener, Ezra - 408
Michot, Norbert Louis 409
Moore, Thomas 409
Pir£, Louis 410
Ravenel, Henry William 41 1
Trimmer, Kirby 412
Wawra, Heinrich 412
Winter, Heinrich Georg 413
Wittstein, Georg Christian . . . . . . .415
F. RECORD OF CURRENT LITERATURE.
1. Books and Pamphlets ........ i, xliii
2. Periodical Literature ix, liii
On some points in the Histology and Physio- logy of the Fruits and Seeds of Rhamnus.
BY
H. MARSHALL WARD, M.A., F.L.S.,
Fellow of Christ's College , Cambridge, and Professor of Botany in the Forestry School, Cooper’s Hill,
ASSISTED BY
JOHN DUNLOP.
With Plates I and II.
OME time ago my attention was directed to some curious
O facts about ‘ Persian Berries,’ the fruits of certain species of Rhamnus used in dyeing. It had long been known that a beautiful golden yellow solution can be obtained by simply macerating these fruits in water, and various re- searches on the part of chemists had demonstrated that the dye is obtained chiefly if not entirely from the husks (peri- carps) ; at the same time dyers and others knew that the crushed berries yield a satisfactory colouring matter, whereas the pericarps alone do not. For some reason it is necessary to employ the inner parts of the fruits as well as the pericarps ; these inner parts of course include the seed when the berries are crushed whole, as is the usual practice. Various species of Rhamnus — R. Amygdalina , R. infectorius (R. oleoides1), R. saxatilis , &c. — are employed as ‘ Persian Berries,’ and although the following remarks apply particularly to R. infectorius , there are reasons for believing that they may apply generally to other species also.
1 Mr. Thiselton Dyer informs me that this is a synonym of R, Amygdalina .
[ Annals of Botany, Vol. I. No. I. August 1887. ]
B
2 Marshall Ward and Dim lop.
In 1842 Fleury examined a yellow dye got from the fruits of a Rhamnus ; a little later Kane obtained a body which was called chrysorhamnm from unripe fruits, and another from ripe fruits which he named x author hamnin. Gellatly in 1851 gave a complex formula (C48 H56 028) to this xanthorhamnin, and stated that dilute sulphuric acid causes it to break up into a body called rhamnetin and grape-sugar — in other words, that xanthorhamnin is a glucoside. This was con- firmed subsequently.
In 1879 Liebermann and Hormann, employing R. infec- torius , confirmed the foregoing, and found that no dye (or the merest traces) is obtained from the seeds, but that it exists in the husks (pericarps). They got the glucoside xanthorhamnin, which is soluble in water and alcohol, but not in ether, benzole or chloroform, and assigned to it the formula C48 H66 029. It is soluble in alkalies ; ferric chloride turned the solution brown. Sulphuric acid causes it to break up into glucose and rhamnetin.
They also found that the xanthorhamnin breaks up under the action of some ferment in the fruit, the products of this reaction being a colouring body, rhamnin and glucose.
This was practically the position of our knowledge, when my attention was directed to an experiment performed by Mr. T. E. Lightfoot, of Accrington, a gentleman interested in dyeing, and who was then investigating the qualities of the different yellow dyes obtainable from ‘ Persian Berries.’ Mr. Light- foot has informed me by letter that he found that a decoction of the uninjured berries yielded a poorer colouring liquor than one obtained from the ground or crushed ‘ berries.’ He then took some of the fruits, and split them, separating the outer shells— the chief part of the pericarp — from the ‘kernels’; these ‘ kernels’ are the seeds, and they are covered by a thin hard covering which, as will be seen shortly, is the endocarp.
A weighed quantity of the outer pericarps was then used for making a decoction, and a piece of cloth dyed with the liquor; in another vessel the same weight of ‘shells’ (peri- carp) was used, but a few of the ‘kernels’ (seeds) added.
3
On the Fruits and Seeds of Rhamnus .
In the second case the colouring matter was a brilliant golden yellow, whereas the former gave but a poor lemon- yellow dye.
The outer pericarps were next digested in water at 45°C. for about one hour, and the clear yellow filtered liquor was placed aside with a few ‘kernels’ (seeds) added; in thirty minutes or so a light yellow powder fell to the bottom, C 02 being given off meanwhile.
‘ Kernels’ were then split up into four parts, and these parts kept separate. (1) The shell or husk of the ‘ kernel’ (i. e. the endocarp) ; (2) A greyish white matter (i. e. endosperm) ; (3) the infolded rims of the seed proper; (4) a yellow sub- stance— the embryo — inside the seed.
To clear decoctions of the outer pericarps Mr. Lightfoot then added the different parts of the dissected kernels, and found that in every case the yellow powder fell after a time, but more quickly where the rims of the seed were added. The action was destroyed by boiling.
The obvious explanation of the above experiments is that a ferment, localised in the ‘kernels’ (seeds), acts on the yellow substance dissolved from the pericarps.
Having obtained some fruits of Rhamnns infect or ius from Kew, I set to work to investigate the matter independently.
I found that if the whole fruits are steeped in water, and kept at 35°C., a quantity of bright yellow substance collects around the swollen mass, and if squeezed out gradually forms a slight precipitate. On breaking these steeped fruits there is abundance of glairy yellow substance inside, not easily washed away. If the fruits are broken up firsts however, a copious precipitate soon falls ; this is yellow, and finely crystalline, and is evidently the rhamnin of the chemists1. The filtered liquor after this experiment reduces Fehling’s solution, and contains relatively large quantities of glucose.
I then repeated the experiments with the various parts of
1 Husemann, ‘ Pflanzen-stoffe,’ vol. ii. 1884, p. 889, where the chemical litera- ture is quoted.
4 Marshall Ward and Dunlop.
the seeds and the endocarp. The chief difficulty here was to obtain perfectly clean portions. It was easy to separate the endocarp ; far less easy to separate the testa of the seed from the contents. The large yellow embryos slip out pretty easily. I doubt whether the testa was ever got perfectly free from the nucellus in these earlier trials. A decoction of the freed outer pericarps was then made, and the clear yellow filtered solution placed in test-tubes and treated as follows : —
A : was left alone.
B : testa was added.
C : endocarp was added.
D : endosperm was added.
E : embryo was added.
All the experimental tubes were placed in a warm chamber and kept at 35°C. After half-an-hour I found a copious yellow crystalline precipitate falling in B, and faint traces of a similar precipitate in E. In all the other tubes the liquid was still clear. After eight to twelve hours traces of a pre- cipitate were observable in the other tubes, but it was more than a day after that any noteworthy changes were observable.
Evidently something in the testa (and possibly in the embryo also) acts as a ferment on the yellow glucoside in the pericarp. I repeated the experiment B, but boiled the solution after adding the testa ; a coarse cloudy precipitate formed. It became probable later that this was due to the boiling. I again repeated experiment B, with the following modifications. In one case I employed a glycerine-extract of the testa ; this was effectual, as before. In another case I used a filtered water-extract of the testa ; this was effectual also, but not so if boiled first. There seemed to be a soluble ferment in the testa of the seed then, and it is obvious that the results confirmed previous experiments.
It was now time to examine the tissues histologically, and I confined my attention at first to the testa and pericarp. In the cells of the outer pericarp are brittle waxy yellow masses (Fig. 6), which dissolve at once in water, and are evidently masses of the glucoside (xanthorhamnin). The
5
On the Fruits and Seeds of Rhamnus.
testa contains thick- walled pitted cells (Figs. 4 and 12) which contain a peculiar finely granular substance, which dissolves at once on adding water and disappears. I was for some time strongly inclined to regard this fine grey powder as the ferment with which we had been experimenting. To test the accuracy of this conclusion I made very thin sections of the dry testa, and placed them directly into solutions of the glucoside from the pericarp ; the sections were from all parts of the testa. In less than half-an-hour I found a semi- crystalline precipitate resembling the precipitates of rhamnin obtained in the test-tubes.
I then asked Mr. John Dunlop, who was at that time working in my laboratory at the Owens College, to go over the anatomy and histology of the fruits and seeds of Rhamnus with me ; this he was good enough to do, and most of the figures in the plates are due to his pencil. We confined our attention to Rhamnus infectorius at the time ; later on I examined the histology of several other species.
The fruit of Rhamnus infectorius is a berry-like drupe (Fig. 1) with a dry waxy outer pericarp, and a thin woody endocarp : within this are three or four erect seeds, which, if separately and completely enclosed in the sclerenchymatous endocarp, might almost be called nutlets (Fig. 2). A hori- zontal transverse section made equatorially across the drupe reveals the seeds lying loosely in the loculi of the dry fruit, one in each loculus, enclosed in the hard thin endocarp. On splitting this endocarp the seeds fall out, being loose within it ; each seed is smooth and shining, brown in colour, and with a longitudinal deep groove on the dorsal side. A trans- verse section of the seed shows a hard brown testa, doubled in at the dorsal groove (Figs. 3 and 21), the margins of the groove being thickened and harder than the rest. The cavity within the testa is nearly horseshoe-shaped in trans- verse section, and filled with white endosperm, in which lie the cotyledons : these are face to face and also horseshoe-shaped in transverse section. Between the endosperm and testa were several rows of broken down and disorganised cells, evidently
6 Marshall Ward and Dunlop .
the remains of the nucellus. In the dry state all the parts are shrunken, and a large hollow cavity exists on the dorsal side of the endosperm— between it and the testa. The various parts of the fruit were then separated and sections cut so as to exhibit their structure. The outer pericarp is brittle and waxy in texture : their sections, in the dry state, show (Fig. 5) an outer epidermal layer, the external cell-walls of which are strongly cuticularised. With the exception of certain small granules, looking very like plastidia, these cells and those immediately below them have no contents. Immediately below the epidermal layer are four or five rows of hypodermal cells, the outer rows consisting of regular rectangular cells, which in the inner rows become less and less regular and smaller, all however containing small corpuscles near the interior of their walls. These seem to be chlorophyll-cor- puscles. Below these cells are larger, thin-walled, parenchy- matous cells containing a yellow amorphous substance which completely filled up the cavity of the cell (Figs. 5 and 6).
Water was then added to the dry sections while still under the microscope ; the cell-walls, etc. swelled up and the yellow substance in the cells at once dissolved completely, colouring the water yellow and leaving the cavities of the cells empty ; the latter were then seen to be thin-walled and parenchyma- tous (Fig. 5).
To other dry sections under the microscope glycerine was added ; they again swelled up and the yellow substance in the parenchymatous cells again dissolved, but not so rapidly as in water. Sections were treated in a similar manner with alcohol, chloroform and ether ; the yellow substance dissolved to a very slight extent in alcohol, but was insoluble in chloro- form and ether. Thus the yellow substance was not a wax, resin or fat, any of which would probably have dissolved in any of the last three reagents, and not in water or glycerine.
The histology of the endocarp was next made out. Its inner yellow lining was stripped off and examined ; it was found to consist of a layer of long thin-walled cells containing a yellow waxy- looking substance, and on adding water the
7
On the Fruits and Seeds of Rhamnus.
contents cracked and dissolved like the substance contained in the cells of the outer pericarp, leaving the cell cavities empty and allowing the shape of the cells to be more clearly seen (Figs. 8 and 9). On treating dry sections with glycerine, the yellow substance again dissolved, but more slowly than in water (Fig. 8). This yellow substance was treated with alco- hol, chloroform and ether, and acted in the same way as the yellow substance in the parenchyma cells of the outer pericarp. Transverse sections were then cut of this inner husk, and the cells appeared rectangular, the cell-wall being slightly thick- ened on the exterior surface (Fig. 10).
As regards the rest of the endocarp, thin transverse sections were cut, and were found to consist of a number of rows of hard sclerenchymatous cells, of which the lumina were nearly obliterated, having a very distinct middle lamella between the cells, and with a large number of pits radiating from the lumina to the middle lamella, corresponding to pits radiating from the lumina of contingent cells (Fig. 7).
Thin transverse sections of the testa were then cut, and it was found to consist of a single row of sclerenchymatous cells, with a number of pits radiating from the centre of each lumen, the cell-cavity containing a greyish substance which diffused out of the cell on adding water to the section. The middle lamella of the cell-wall was very well marked (Figs. 11 and 12).
Thin tangential sections of the endosperm were cut, the tissue was found to consist of thin-walled parenchyma, the cells containing protoplasm and various other bodies. On adding water to the sections oily drops separated out in the cells, and exuded at the sides of the sections ; the water was then removed and alcohol added, the fatty drops disappeared (Fig. 14). Fresh sections were cut and placed dry in alcohol and examined in glycerine, the fat had dissolved and a number of small grains closely packed were left in the cells. Sections which had been treated with alcohol as before were examined and water added while under the microscope, and these grains dissolved after swelling up. Thus* the endosperm contained
8 Marshall Ward and Dunlop.
fats and grains which there were grounds for thinking were aleurone grains. To confirm this supposition sections were cut and placed in a two per cent, solution of 'mercuric chloride in absolute alcohol, and were left in it for about forty- eight hours, washed for half a minute in water, stained rapidly with eosin, and mounted in a solution of a neutral salt, potas- sium acetate being used. On examining the sections a large number of aleurone grains were found in the cells, but on examining the grains no enclosure could be detected within them (Fig. 15). Sections were placed in the alcoholic solution of mercuric chloride as before and left for twenty-four hours, then washed in absolute alcohol, stained rapidly with eosin, washed for half a minute in water, and mounted in a solution of potassium acetate. On examining these sections it was found that the aleurone had been dissolved out by washing in the water, leaving a reticulum of protoplasm in which the aleurone grains had been lying, and showing a well-stained nucleus in each cell (Fig. 16).
Sections of the cotyledons were cut and examined dry, they were a light yellow in colour ; on adding water the cells became more distinct, and oily globules separated out, which on removal of the water dissolved in alcohol, chloroform and ether. The sections consisted of about six or seven rows of cells, the outer row on each side being arranged very regularly and with their outer walls slightly thickened. The second row on the one side consisted of columnar cells, while those in the centre were more irregular and larger, and with a number of intercellular spaces between them (Fig. 17).
Sections were treated with the alcoholic solution of mercuric chloride for twenty-four hours, washed for half a minute in water, stained with eosin and mounted in a solution of potas- sium acetate. On examining the sections it was found that the cells contained a large amount of aleurone, which seemed to be similar to that contained in the endosperm, as no enclo- sure could be detected within the grains which, on the addition of water, swelled up and dissolved.
The cells of the embryo are thin-walled and parenchyma-
9
On the Fruits and Seeds of Rhamnus .
tons, containing protoplasm, aleurone and fats, together with a yellow substance, the nature of which I was unable to make out, but which did not seem to be identical with the yellow substance contained in the outer pericarp and endocarp, and this supposition was strengthened by the action of the various parts on one another, this yellow substance contained in the cotyledons not acting in the same way as the yellow body contained in the pericarp and endocarp.
On cutting sections of the embryo and staining with methyl green a prominent nucleus was seen in each cell (Fig. 18).
The reactions of the whole berry and its various parts were next investigated with the following results. The whole berry was digested in distilled water for about twenty-four hours, the temperature being 30°C. ; at the end of this time there was found to be a copious yellow precipitate, which on examination under the microscope was found to consist of clumps of spherical masses aggregated together (Fig. 20). The supernatant fluid was poured off from the precipitate, and to it were added two or three drops of Fehling’s solution ; after warming, a copious brick-red precipitate of cupric oxide was thrown down showing that a glucose was present in the solution, as no precipitate was obtained when the solution was similarly heated without adding Fehling’s solution.
The pericarp was stripped off a number of fruits and digested in distilled water for about twenty-four hours, the temperature being about 30°C. The solution was a pale yellow at the beginning, but after digestion the colour was more pronounced and darker, but no precipitate was obtained. Fehling’s solution was added to this liquid and warmed, but no precipitate was thrown down. The pericarp was digested in distilled water for twenty-four hours, at a temperature between 6o° and 8o°C., and at the end of the time a yellow precipitate was obtained, which was found to consist chiefly of clumps of long needle-shaped crystals (Fig. 19) ; the liquid filtered off from these gave a precipitate with Fehling’s solu- tion. Hence the yellow substance contained in the pericarp, which from its micro-chemical and other reactions, solubility
i o Marshall Ward a7id Dunlop.
in water, and insolubility in alcohol, chloroform and ether, must be a glucoside, is split up on heating to about Jo°C. into glucose and a semi-crystalline substance.
The endocarp, on treatment in the same way as the peri- carp, acted in the same manner; on digestion at 30°C. no precipitate was obtained, and the solution gave no glucose reactions ; on digestion at a temperature about jo° C. a crystalline precipitate was again thrown down, and the filtrate from this yields a precipitate on warming with Fehling’s solution. Thus the substance in the endocarp acts in the same manner as that in the pericarp, both probably being the same glucoside, but contained in much larger quantities in the pericarp. If the seeds be removed and digested for twenty- four hours, at a temperature of 30°C, an opalescent clear solution is obtained ; if the seeds are digested at 70° C. the solution still remains clear, showing that the glucoside is not contained in the seed.
The pericarp was digested in water for twenty-four hours with the endocarp ; no change took place.
The pericarp was digested in water for twenty-four hours, at a temperature of 30°C., and the solution filtered off, and added to the solution obtained on digesting the seeds for twenty-four hours at 30°C. After leaving them at 30°C. for half-an-hour a precipitate was obtained, which soon became very copious, and which was found to consist chiefly of needle- shaped crystals, and also of the semi-amorphous masses obtained by digesting the whole fruit (Figs. 19 and 20). The filtrate from this precipitate yielded, on warming with Fehling’s solution, a copious precipitate. Thus the yellow glucoside has been again split up into glucose and a crystalline substance, and this time not by heat, therefore it must have been by means of some substance contained in the seed.
If the solution obtained from the seeds is boiled for ten minutes and added to a solution of the pericarp, and allowed to stand for twenty-four hours at a temperature of 30°C., no precipitate is obtained, and the solution does not yield a pre- cipitate on warming with Fehling’s solution. Hence the
On the Fruits and Seeds of Rhamnus . 1 1
action of the substance contained in the seed which converted the glucoside into glucose and another substance has been de- stroyed by heat, and consequently that substance is a ferment.
There was thus a ferment in the seed which broke up the glucoside contained in the pericarp and endocarp. I then proceeded to find out in what part of the seed this ferment was contained. The testa was stripped off a number of seeds and digested at the usual temperature for an hour ; a clear solution was obtained, which was added to a solution of the pericarp, obtained by digestion as before, and a copious yellow precipitate was obtained in about twenty minutes. The solution obtained from the testa on digestion was boiled for ten minutes and added to the solution of the pericarp ; after twenty-four hours no precipitate was obtained. The filtrate in the first instance yielded a precipitate with Fehling’s solu- tion, but none was obtained in the second. Hence the ferment, the action of which was destroyed by boiling, ap- peared to be contained in the testa.
The rest of the seed was taken and digested, and the solu- tion obtained was added to a solution of the pericarp ; in about an hour a copious yellow precipitate was obtained, and the filtrate from this precipitate gave glucose-reactions. Hence the ferment, the action of which was also destroyed by boiling in this case, is also contained in the rest of the seed either in the embryo or endosperm, or both.
The embryos of a number of seeds were dissected out and digested as usual, and the solution obtained from them was added to the solution of the pericarp ; after a few hours a yellow precipitate was again obtained, the filtrate from which yielded a precipitate on warming with Fehling’s solution. Hence the ferment appeared to be contained in the embryo.
The endosperm was removed from a number of seeds and digested for twenty-four hours, at a temperature of 25°C., and to the solution obtained was added the solution obtained by digesting the testa, and the mixture was allowed to stand for twenty-four hours at the same temperature ; at the end of the time no precipitate was obtained, and the solution gave no
1 2 Marshall Ward and Dimlop.
glucose-reaction, hence the ferment was not contained in the endosperm.
On cutting sections it was noticed that there was a large quantity of a yellow substance in the cells, which however differed considerably from the glucoside of the pericarp in its micro-chemical reactions. In order to see if it was different from the glucoside the embryos of a number of seeds were digested as usual, and to this solution was added a solution of the testa ; on allowing to stand for twenty-four hours no precipitate was obtained, and it was therefore concluded that the yellow substance of the embryo was not the same as the glucoside of the pericarp.
Thus in the pericarp there is contained a glucoside, which is split up by a ferment contained somewhere in or near the testa and embryo into glucose and a crystalline substance.
It seemed to be proved from the foregoing observations that the ferment which decomposes the glucoside (xantho- rhamnin), contained in the cells of the pericarp, is localised in the testa of the seed ; whether any traces existed in other parts was not proved. On adding water to the intact fruits the soluble ferment passes out and acts on the dissolved glucoside from the pericarp, breaking it up into rhamnin and glucose. If this occurs the precipitate will be withheld chiefly inside the fruits, thus explaining why the dyers should crush their fruits, since it is the insoluble semi-crystalline precipi- tate which they want.
Before proceeding to show where the ferment really is — in the raphe, a discovery which I only made some time after — it should be stated that the above observations were unavoidably put aside owing to the pressure of new duties. I had, how- ever, made some observations which led to the suspicion that the ferment is even more localised than it had so far been shown to be.
Series I.
The following experiments were made with ‘ Persian berries’ — the fruits of Rhamnus infectorins— obtained from Kew.
13
On the Frtuts and Seeds of Rhamnus.
A. Six of the fruits were placed intact in cold distilled water, in a labelled test-tube, and the whole kept at 15° to 1 6°C. in a hot-house for twenty-four hours, perfectly at rest.
The fruits all floated. In the course of some hours a yellow cloud was observed round the fruits. After twenty hours a copious yellow precipitate had fallen to the bottom of the pale, lemon-coloured liquor : a similar precipitate was sticking to the outsides of the fruits.
B. Six of the fruits were slightly crushed , and treated in all respects exactly as in A.
The cold water at once turned pale lemon colour, diffusion streaks falling from the floating pieces of fruit as the water dissolved the yellow glucoside from the pericarps : in ten to fifteen minutes the solution was of an intense, clear lemon colour. In two hours a bright golden-yellow precipitate was falling to the bottom, and in three hours there was a copious precipitate1.
C. Six of the fruits were placed intact in a tube as before, but boiled for ten minutes : then treated exactly as in A.
A deep golden, clear liquor at once resulted : the fruits fell to the bottom of the tube, leaving the perfectly clear solution above. There was no precipitate — not even a cloudiness