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Among fossil plants the following genera and species exhibit the phenomenon of homoeomorphy:

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6. Methods of Mapping Plant Distribution. By T. W. WOODHEAD.

WEDNESDAY, SEPTEMBER 16.

The following Papers were read :-
:-

1. On some Anatomical Features of the Scutellum in Zea Mais.
By ETHEL SARGANT and AGNES ROBERTSON.

The epidermis of the scutellum develops into a well-marked epithelium over the face which is in contact with the endosperm. We have found that this epithelium folds in on itself in places, forming narrow clefts of considerable depth in the dorsal surface. Both sides are of course lined with the epithelial layer, and the cleft is so narrow that they often touch each other. Traces of secretion are, however, commonly found within these structures which may fairly be described as glands. Their number and size vary in the individuals examined. Their distribution over the dorsal surface of the scutellum is also variable, but they are least frequent near the apex and in the regions bordering on the median longitudinal section; indeed, they are often quite absent from these parts. The glands are fully formed in the ripe seed, and we have not traced their development.

Similar glands are found in the allied genus Coix, but in the individuals of C. lachryma-Jobi which we examined they were less well developed than in Zea. Vascular tissue.-The main bundle of the scutellum runs upwards to the apex from the level at which it is inserted on the stele of the axis. Just above its insertion this massive bundle is collateral, with some slight suggestion of a double structure. The single group of xylem is on the ventral side of the bundle. Higher up in the scutellum the xylem begins to creep round the phloëm, at the same time throwing out short branches consisting of tracheids and albuminoid cells. Near the apex the main bundle becomes amphivasal, and slender branches are given off profusely from the dorsal face of the bundle. They penetrate all the tissue on the dorsal side of the scutellum apex, but are most frequent near the midrib. These little branches always end freely just under the dorsal surface. commonly about two rows of cells below the epithelium. In character they resemble the transfusion tissue described by Professor Weiss in Stigmarian rootlets.

We have not observed any relation between the terminations of the vascular branches and the epithelial glands. These terminations occur in those parts of the scutellum where the glands are least frequent.

2. Experiments with the Staminal Hairs of Tradescantia.
By HAROLD WAGER.

If the staminal hairs or petals of the purple-flowered Tradescantia virginica be killed, either by heat or by certain fixing reagents, the coloured sap in the dead cells is at once taken up by the protoplasm, and especially by the nucleus, which becomes deeply stained red, blue, or greenish blue, according to the nature of the reagent used. The alcohols and corrosive sublimate give a blue or bluish-green coloration; acid alcohol or Pereny's fluid red, and if killed by heat the coloration is reddish violet.

Preparations thus made may be mounted permanently either in glycerine or

Canada balsam. Petals of Iris, Vetch, or blue Linum, &c., do not give the same results. The coloured sap escapes from the cell as soon as the protoplast is killed. In Tradescantia it cannot escape so rapidly, owing apparently to the presence of a cuticularised membrane around each cell, and it consequently remains in contact with the nucleus a sufficiently long time to stain it. By means of this cuticularised membrane the penetration of fixing fluid appears to be to some extent prevented. The resistance of the cells to the action of reagents is, however, very variable. In methylated spirit the protoplasmic movement ceases in most cells at the end of 1 minute, but was still observable in a few cells at the end of 23 minutes. In 3 minutes a large number of the nuclei had become stained blue. In 70 per cent. alcohol protoplasmic movement was visible in a few cells at the end of 11 minutes, but was very slow and had ceased altogether in 11 minutes. In 70 per cent. alcohol, with a few drops of 5 per cent. solution of hydrochloric acid, the movement was visible in some of the cells at the end of 7 minutes; in Pereny's fluid at the end of 17 minutes, but had entirely disappeared in 17 minutes; in saturated solution of corrosive sublimate the movement stopped at once (in 15 to 30 seconds) in most cells, but was still visible in a few at the end of 2 minutes, when it ceased altogether. In a 2 per cent. solution of potassium bichromate movement was observable 4 hours after immersion, and in two other cases for 24 hours; in one case the hairs were placed in a small bottle of the solution. With a 1 per cent. solution of chromic acid movement was visible 1 hour after the reagent was placed upon the hairs, and in the case of complete immersion of a few hairs in a bottle, 1 hour 25 minutes after immersion. The colour-changes which take place are: (1) The purple sap turns light blue, then greenish; (2) the nucleus and cytoplasm take up the stain; and finally (3) the colour disappears entirely, leaving only the brownish colour due to the reagent. In a 10 per cent. solution of ammonia the movement continues in some of the cells for 16 minutes. The colour-changes are interesting: (1) the sap first of all becomes light blue, with slow cytoplasmic movement; (2) dark blue, movement stopped, and coagulation taking place; (3) green, protoplasmic strands completely broken up, coagulation masses abundant; (4) bright green, cytoplasmic strands almost completely broken up and disintegrated. The nucleus remains colourless, and when the green colour begins to disappear, it is found at one end or on the side of the cell, surrounded by a thick layer of granules from the cytoplasm. It then begins to swell up, the sap becomes lighter and lighter in colour, and gradually disappears, and finally there is left in the cell only a colourless mass of disintegrated protoplasm.

Under normal conditions the flowers of Tradescantia last for one day only. They open early in the morning and begin to close up at night. This is accompanied by disintegration of the cells of the petals and stamens, which become converted into a pulpy mass in the course of about two days. The protoplasm is completely broken up in the majority of the cells, just as in the ammonia solution.

If, however, staminal hairs be taken from the flower in the middle of the day and placed in water, the disintegration of the cell does not take place for a much longer time, even after the cell is dead. The cells may remain in the living condition for several days. In one of my experiments a fairly brisk protoplasmic movement was visible in two or three cells twenty-four days after being placed in water. In the dead cells the nucleus is coloured green and remains so for several days.

Staminal hairs taken from an open flower later in the day (8 P.M.) already showed signs of disintegration, and in the course of two days had become completely disintegrated.

Hairs completely embedded in a layer of vaseline still showed protoplasmic movements in a few of the cells at the end of six days. In the dead cells the coloured sap could not escape, but the nucleus did not become stained, and in a very short time both it and the cytoplasm had become almost completely disintegrated. This seems to indicate that possibly the cell-sap plays some part in the rapid protoplasmic disintegration which takes place when the flower is in its pulpy condition. But further experiments are necessary before this can be satisfactorily determined.

3. On the Localisation of Anthocyan (red-cell sap) in Foliage Leaves.

By J. PARKIN, M.A.

There is an impression, the author believes, amongst botanists that the pigment known as anthocyan resides as a rule in the epidermis of the leaf. No extensive investigation seems to have been made to see how far this view is correct. The author has so far submitted to microscopical examination four hundred different instances of anthocyan occurring in foliage leaves. The species investigated include monocotylous and dicotylous trees, shrubs, and herbs, together with a few ferns. The anthocyan of leaves can be divided into four main categories :—

(1) The transitory anthocyan of young leaves.-This appears during the development of the leaf, disappearing again on maturity. It is a marked feature of tropical foliage, though it occurs less strikingly in many plants of temperate regions. Number of species so far examined, 235. The anthocyan is confined to the mesophyll in 64 per cent. of these, to the epidermis in 20 per cent., and is common to both in 16 per cent.

(2) Autumnal' anthocyan.-This appears in many old leaves as they change colour previous to their fall. Number of species examined, 81. The anthocyan is confined to the mesophyll in 78 per cent. of these, to the epidermis in ¡Il per cent., and is common to both in 11 per cent.

(3) The permanent anthocyan of mature leaves.-This appears as the leaf matures, and persists throughout the life of the leaf as a normal character. This category includes (a) leaves with uniformly red lower surfaces; (b) leaves with definite pigmented areas in the form of spots, blotches, or zones; and (c) leaves of horticultural varieties, with coloured foliage. Number of species examined, 54. The anthocyan is confined to the epidermis in 70 per cent. of these, to the mesophyll in 17 per cent., and is common to both in 13 per cent.

(4) The accidental anthocyan of mature leaves.-In distinction from (3) this is not normally present in the mature leaves, but arises only under exceptional conditions, such as: (a) excessive insulation, followed by cool nights, seen in Alpine plants and in evergreens during winter; (b) the result of injury, a reddish zone often appears round a wound in a leaf; and (c) through the accidental exposure of the lower surface to the full rays of the sun. The greater sensitiveness of the under surface of the leaf to reddening is a fact of some interest and seems to have been unrecorded.

Thirty cases have been examined, and in the majority of these the anthocyan was confined to the mesophyll.

In summary, then, the anthocyan of young leaves and of autumnal leaves is usually confined to the mesophyll; that of mature leaves, when a normal feature to the epidermis, and when an exceptional one to the mesophyll. Thus the mesophyll, i.e. the chlorophyll cells, appears to be the usual, and, perhaps, the more primitive position for the red sap in leaves.

The fact that anthocyan is usually present only in the mesophyll of young leaves seems to weaken somewhat the view that its function there is to protect the chlorophyll by absorbing the destructive solar rays.

The author is inclined to think that the biological significance of this pigment has been overrated, and that the majority of cases may be capable of explanation on purely chemical or physiological grounds.

4. The Forest Resources of Australia available for British Commerce. By E. T. SCAMMELL.

Forest conservation and development.-One of the most important duties requiring the early attention of the Federal Government of Australia is that of dealing with the forest resources of the Commonwealth. At present the forest laws and regulations in force, according to the judgment of the Victorian Royal

Commission on Forestry (1901), are 'weak, unsystematic, and inefficient.' This has been acknowledged at different times by the various Governments of the Australian States, and desultory efforts to introduce some scheme of State regulation have been made, but no scientific and comprehensive plan, on the lines laid down by France, Germany, or India, has, apparently, been seriously considered or, at any rate, attempted. Referring to the need of forest conservation and management in Greater Britain, Professor W. Schlich says: 'Surely the time has come-or rather it came some time ago-for a more vigorous forest policy on sensible lines throughout the Empire. Let us strive to introduce systematic forest management, more particularly into Canada and Australasia.'

The labours of the Victorian Commission have resulted in a strong recommendation that the action of the Government of India should be followed by the legislatures of Australia, and a commission has been appointed for the purpose of obtaining information and of recommending measures for dealing with the forests in Western Australia.

The forest areas of Australia.-The magnitude and importance of the interests involved may be judged by the fact that the forest areas of Australia comprise 107,037,000 acres of marketable timber, or nearly half the areas of the forest lands of Europe, excluding Russia. Of these areas Queensland possesses about forty million acres, New South Wales twenty million, Victoria twelve million, South Australia four million, Western Australia twenty million, and Tasmania eleven million. To this should be added considerable areas in Queensland (over 100 million acres) and in Western Australia (over seventy million acres) covered with inferior timber, which has a local value for building and for general purposes.

Their nearness to the coast.-Most of the important forests of Australia are fairly accessible from the sea. This especially applies to the belts of jarrah and karri in Western Australia, and to Tasmania, whose forests of blue gum and stringy bark grow down to the shores of that island.

The commercial timbers of Australia.—The timbers of the Commonwealth are of many varieties, and some of them are of high commercial value. The chief of these, as shown in the great work of the late Baron von Mueller, are the eucalypts. Of this valuable timber alone there are over 150 species. Besides the eucalypts there are many kinds of casuarinas (the Australian oak), some conifers (the Moreton Bay pine, the cypress pine, the brown pine, or colonial deal, and others), many acacias (the Australian wattle), Banksias, and numerous other varieties.

At present, however, the range of Australian wood available for British commerce is limited. Western Australia and Tasmania are the only States that have seriously dealt with the question of exporting timber or of using their forest resources as a valuable commercial asset.

Conclusion. My object in bringing forward at these meetings a practical subject of this nature is to aid, so far as one can, the efforts that are being put forth by scientific as well as commercial men to promote the interests of our colonies, the development and progress of which cannot fail to be of deep concern to the members of this Association. It will, I am sure, be readily granted that the more widely the products and the possibilities of our great colonial possessions are known, the more clearly will the fact be accentuated that our interests, whether scientific, industrial, or commercial, are one.

5. On the Preservation, Seasoning, and Strengthening of Timber
by the Powell Process. By WM. POWELL.

The timber to be treated is put into a solution of common sugar and water (or the refuse syrup of beet-sugar refining, with added water) and boiled in this solution until the air in the interstices of the timber is exhausted; the timber, still covered by the syrup, is allowed to cool down to 30° C. or less, by which time the air-spaces are filled with syrup. The timber is then removed and dried at a fairly high temperature in stores,

The process is a very simple one, though naturally each particular kind of timber requires some modification of the process suited to its nature.

Numerous experiments have been made by independent authorities with, in many cases, astonishing results. The breaking strain of yellow pine had been increased from 50 to 100 per cent., and all timber so treated was improved in toughness and strength. Paving blocks of various kinds of timber had been processed and then soaked for fourteen days in water, when it was found that the Powellised' blocks only absorbed from one-fifth to one-half the quantity taken in by the natural wood.

Other interesting figures and details were given, and specimens of 'Powellised' and natural timber exhibited showing the change effected by the process in the various kinds of wood in daily use.

6. Plants on the Serpentine Rocks in the North-East of Scotland.

By W. WILSON.

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