from the study of the nutrition of bacteria, arrived at some general conclusions in the same direction. Bokorny appears recently to have similarly experimented on alga. Neither writer, however, seems to have been acquainted with Acton's work. The general conclusion which I draw from Loew is to strengthen the belief that form-aldehyde is actually one of the first steps of organic synthesis, as long ago suggested by Adolph Baeyer. Plants, then, will avail themselves of ready-made organic compounds which will yield them this body. That a sugar can be constructed from it has long been known, and Bokorny has shown that this can be utilised by plants in the production of starch. The precise mode of the formation of form-aldehyde in the process of assimilation is a matter of dispute. But it is quite clear that either the carbon dioxide or the water, which are the materials from which it is formed, must suffer dissociation. And this requires a supply of energy to accomplish it. Warington has drawn attention to the striking fact that in the case of the nitrifying bacterium, assimilation may go on without the intervention of chlorophyll, the energy being supplied by the oxidation of ammonia. This brings us down to the fact, which has long been suspected, that protoplasm is at the bottom of the whole business, and that chlorophyll only plays some subsidiary and indirect part, perhaps, as Adolph Baeyer long ago suggested, of temporarily fixing carbon oxide like hæmoglobin, and so facilitating the dissociation. Chlorophyll itself is still the subject of the careful study by Dr. Schunck, originally commenced by him some years ago at Kew. This will, I hope, give us eventually an accurate insight into the chemical constitution of this important substance. The steps in plant metabolism which follow the synthesis of the proto-carbohydrate are still obscure. Brown and Morris have arrived at the unexpected conclusion that cane-sugar is the first sugar to be synthesised by the assimilatory processes.' I made some remarks upon this at the time, which I may be permitted to reproduce here. "The point of view arrived at by botanists was briefly stated by Sachs in the case of the sugar-beet, starch in the leaf, glucose in the petiole, cane-sugar in the root. The facts in the sugar-cane seem to be strictly comparable. Cane-sugar the botanist looks on, therefore, as a 66 reserve material." We may call "glucose the sugar "currency" of the plant, cane-sugar its "banking reserve." 'The immediate result of the diastatic transformation of starch is not glucose, but maltose. But Mr. Horace Brown has shown in his remarkable experiments on feeding barley embryos that, while they can readily convert maltose into canesugar, they altogether fail to do this with glucose. We may conclude, therefore, that glucose is, from the point of view of vegetable nutrition, a somewhat inert body. On the other hand, evidence is apparently wanting that maltose plays the part in vegetable metabolism that might be expected of it. Its conversion into glucose may be perhaps accounted for by the constant presence in plant tissues of vegetable acids. But, so far, the change would seem to be positively disadvantageous. Perhaps glucose, in the botanical sense, will prove to have a not very exact chemical connotation. 'That the connection between cane-sugar and starch is intimate is a conclusion to which both the chemical and the botanical evidence seems to point. And on botanical grounds this would seem to be equally true of its connection with cellulose. 'It must be confessed that the conclusion that "cane-sugar" is the first sugar to be synthesised by the assimilatory processes seems hard to reconcile with its probable high chemical complexity, and with the fact that, botanically, it seems to stand at the end and not at the beginning of the series of metabolic change.' PROTOPLASMIC CHEMISTRY. The synthesis of proteids is the problem which is second only in importance to that of carbohydrates. Loew's views of this deserve attentive study. Asparagin, as has long been suspected, plays an important part. It has, he says, two sources 2 Kew Bulletin, 1891, 35--41. Journ. Chem. Soc., 1893, 673. 1895 31 in the plant. It may either be formed directly from glucose, ammonia (or nitrates) and sulphates, or it may be a transitory product between protein-decomposition and reconstruction from the fragments.'1 In the remarks I made to the Chemical Society I ventured to express my conviction that the chemical processes which took place under the influence of protoplasm were probably of a different kind from those with which the chemist is ordinarily occupied. The plant produces a profusion of substances, apparently with great facility, which the chemist can only build up in the most circuitous way. As Victor Meyer has remarked: 'In order to isolate an organic substance we are generally confined to the purely accidental properties of crystallisation and volatilisation. In other words, the chemist only deals with bodies of great molecular stability; while it cannot be doubted that those which play a part in the processes of life are the very opposite in every respect. I am convinced that if the chemist is to help in the field of protoplasmic activity, he will have to transcend his present limitations, and be prepared to admit that as there may be more than one algebra, there may be more than one chemistry. I am glad to see that a somewhat similar idea has been suggested by other fields of inquiry. Professor Meldola3 thinks that the investigation of photochemical processes may lead to the recognition of a new order of chemical attraction, or of the old chemical attraction in a different degree.' I am delighted to see that the ideas which were floating, I confess, in a very nebulous form in my brain are being clothed with greater precision by Loew. 6 46 In the paper which I have already quoted, he says of proteids: They are exceedingly labil compounds that can be easily converted into relatively stable ones. A great lability is the indispensable and necessary foundation for the production of the various actions of the living protoplasm, for the mode of motions that move the life-machinery. There is a source of motion in the labil position of atoms in molecules, a source that has hitherto not been taken into consideration either by chemists or by physicists.' But I must say no more. The problems to which I might invite attention on an occasion like this are endless. I have not even attempted to do justice to the work that has been accomplished amongst ourselves, full of interest and novelty as it is. But I will venture to say this, that if capacity and earnestness afford an augury of success, the prospects of the future of our Section possess every element of promise. The following Papers were read:- 1. On a False Bacterium. By Professor MARSHALL WARD, F.R.S. The author has isolated from the Thames a form which gives all the ordinary reactions of a bacterium in plate-cultures and tube-cultures in gelatine, agar, potato, broth, milk, &c. It is a rod-like form, 1 μ thick, and up to 2-4 μ long, stains like a bacillus, and cannot be distinguished from a true Schizomycete by the methods in common use. On cultivating it under high powers-one-twelfth and one-twentieth oil immersions from the single cell, however, it is found to form small, shortly branched mycelia the growth and segmentation of which are acropetal. This turns out to be a minute oidial form of a true fungus. Its true nature can only be ascertained by the isolation and culture through all stages from the single cell, according to the original methods of gelatine cultures of Klebs, Brefeld, and De Bary which preceded and suggested the methods employed by bacteriologists; and the facts discovered raise interesting questions as to the character of alleged 'branching' bacteria on the one hand, and the multiple derivation of the heterogeneous group of micro-organisms, termed bacteria in general on the other. 1 Loc. cit., 64. 2 Pharm. Journ., 1890, 773. 2. On the Archesporium. By Professor F. O. Bower, F.R.S. Professor Bower pointed out that the recognition of the archesporium as consistently of hypodermal origin cannot be upheld, and quoted as exceptions Equisetum, Isoetes, Ophioglossum, and especially the leptosporangiate ferns. He laid down the general principle that the sporangia, as regards their development, should be studied in the light of a knowledge of the apical meristems of the plants in question. Where the apical meristems are stratified, the archesporium is hypodermal in the usual sense; where initial cells occur, the archesporium is derived by periclinal divisions of superficial cells. Intermediate types of meristem show an intermediate type of origin of the archesporium. He cited as an illustrative case that of Ophioglossum, admitting that the hypodermal band of potential archesporium, which he had previously described, does not occur always or in all species. But so far from thus giving up the case for a comparison with Lycopodium, he holds that as Ophioglossum has a single initial cell in stem and root, it would be contrary to experience to expect or demand a hypodermal archesporium. 3. Note on the Occurrence in New Zealand of two forms of Peltoid 1 Trentepohliaceae, and their relation to the Lichen Strigula. By A. VAUGHAN JENNINGS, F.L.S., F.G.S. The Trentepohliaceae which form epiphyllous cell-plates are at present known only from the tropics (with the exception of two imperfectly developed forms in the northern temperate zone). They have been recorded from S. America (Bornet), India and Ceylon (the Mycoidea parasitica of Cunningham and Marshall Ward), and the East Indies (Karsten), but not up to the present time from New Zealand. The present paper gives a summary of previous literature, and describes two forms found by the writer in New Zealand. (1) Phycopeltis expansa (new species). This species forms wide-spreading yellow cell-plates on the leaves of Nesodaphne in the North Island (Rotorua), and in the South Island (near Picton). Sporangia of two kinds: (a) enlarged cells of the disc; (b) borne singly on a hooked pedicel supported on a single basal cell. The plant is often associated with brown fungus hyphae growing between the cellrows, but not affecting the growth of the alga. On the other hand, when attacked by different hyphæ, the result is the formation of the lichen Strigula, which in Ceylon was shown by Ward to have for its algal element the Mycoidea parasitica, Cunn. (2) Phycopeltis nigra (new species).-The second form is found also on leaves of Nesodaphne with the Phycopeltis above described, and alone on fronds of Asplenium falcatum. Sporangia in the disc are present, but no trace of sporangia on pedicels is observed. The plant always forms narrow, radiating, and branching bands, never circular discs: the margins often irregular and tending to break into filaments. There are two distinct varieties:-(a) a comparatively large-celled form with barren hairs well developed; (b) a small-celled type entirely devoid of hairs. The most remarkable feature, however, is the colour. On the leaf the plant appears perfectly black, and by transmitted light has the olive-green colour characteristic of many fungi, quite different from any of the ordinary Trentepohlias. The plant is never attacked by fungus hypha, and never takes any part in lichen formation, even when on the same leaf with Phycopeltis expansa and the associated Strigula. 1 Term used for those which form cell-plates (type Phycopeltis), as distinguished from cell-filaments (Trentepohlia). FRIDAY, SEPTEMBER 13. The following Papers were read : 1. Experimental Studies in the Variation of Yeast Cells. The author gave an account of his earlier and more recent investigations. Among the latter he especially dwelt on those in which, by one treatment, varieties were produced that gave more, and by another treatment less, alcohol than their parent cells. He pointed out that the observed variations could be grouped under certain rules. From his researches on the agencies and causes to which variation is due, he found that temperature was the most influential external factor.1 2. On a New Form of Fructification in Sphenophyllum. Graf Solms gave a brief sketch of the history of our knowledge of the fructification of the Carboniferous genus Sphenophyllum. He described the type of strobilus originally named by Williamson Volkmannia Dawsori, and subsequently placed by Weiss in the genus Bowmanites; this fructification has recently been shown by Williamson and Zeiller to belong to Sphenophyllum. The author proceeded to give an account of a new form of strobilus recently obtained from rocks of Culm age in Silesia; this shows certain important deviations from the fructifications previously examined. In the Sphenophyllum strobili from the Coalmeasures the axis bears successive verticils of coherent bracts, the sporangia are borne singly at the end of long pedicils twice as numerous as the bracts, and arising from the upper surface of the coherent disc near the axil. In the Culm species, Sphenophyllum Römeri, sp. nov., the bracts of successive whorls are superposed and not alternate, as described by other writers, in the Coal-measure species; a more important feature of the new form is the occurrence of two sporangia instead of one in each sporangiophore or pedicil. Graf Solms referred to the unique collection of microscopic preparations of fossil plants left by Professor Williamson; he emphasised in the strongest terms the immense importance of the collection, and pointed out how every worker in the field of Paleozoic botany must constantly consult the invaluable type specimens in the Williamson cabinets. 3. The Chief Results of Williamson's Work on the Carboniferous Plants. By Dr. D. H. SCOTT, F.R.S. The origin and history of the late Professor Williamson's researches on the Carboniferous flora were briefly traced. His great work, chiefly, though not entirely, contained in his long series of memoirs in the Philosophical Transactions' of the Royal Society, consisted in thoroughly elucidating the structure of British fossil plants of the coal period, and thus determining, on a sound basis, the main lines of their affinities. Four of the principal types investigated by Williamson were selected for illustration-the Calamarieæ, the Sphenophyllea, the Lyginodendreæ, and the Lycopo diacea. (1) The Calamariea.-Williamson's great aim, which he kept in view all through, was to demonstrate the essential unity of type of the British Calamites, i.e. that they are all Cryptogams, of equisetaceous affinities (though sometimes heterosporous), both possessing precisely the same mode of growth in thickness by means of a cambium, which is now characteristic of Dicotyledons and Gymnosperms. For a fuller account of Dr. Hansen's work, see the Annals of Botany, 1895. His researches have given us a fairly complete knowledge of the organisation of these arborescent Horse-tails. (2) The Sphenophylleæ, & remarkable group of vascular Cryptogams, unrepresented among living plants, but having certain characters in common both with Lycopodiaceae and Equisetacea, are now very thoroughly known, owing, in a great degree, to Williamson's investigations. The discovery of the structure of the fructification, absolutely unique among Cryptogams, was in the first instance entirely his own. (3) The Lyginodendreæ.-The existence of this family, which consists of plants with the foliage of ferns, but with stems and roots which recall those of Cycads, was revealed by Williamson. This appears to be the most striking case of an intermediate group yet found among fossil plants. (4) The Lycopodiacea.-Williamson added enormously to our knowledge of this great family, and proved conclusively that Sigillaria and Lepidodendron are essentially similar in structure, both genera, as well as their allies, being true Lycopodiaceous Cryptogams, but with secondary growth in almost all cases. He demonstrated the relation between the vegetative organs and the fructification in many of these plants, and by his researches on Stigmaria, made known the structure of their subterranean parts. The different types of Lepidodendron, of which he investigated the structure, were so numerous as to place our knowledge of these plants on a broad and secure foundation. The paper was illustrated by lantern-slides, partly from Williamson's figures, and partly original. 4. The Localisation, the Transport, and Rôle of Hydrocyanic Acid in Pangium edule, Reinw. By Dr. T. M. TREUB, Buitenzorg, Java. Five years ago Dr. Greshoff made the remarkable discovery that the poisonous substance contained in great quantities in all the parts of Pangium edule, was nothing else than hydrocyanic acid. This interesting chemical discovery was the starting-point of Dr. Treub's physiological investigations. In microchemical researches hydrocyanic acid presents a great advantage, as compared with the great majority of substances to be detected in tissues by reagents; namely, that the Prussian blue reaction, easily applicable in microchemical research, gives completely trustworthy results. The appearance of Prussian blue in a cell may be accepted as certain proof of the previous occurrence in the cell of hydrocyanic acid, no other substance producing the same reaction. The leaves prove to be the chief factories of hydrocyanic acid in Pangium, though there are other much smaller local factories of this substance in the tissues of other organs. The hydrocyanic acid formed in the leaves is conducted through the leaf-stalks to the stem, and distributed to the spots where plastic material is wanted. The acid travels in the phloem of the fibro-vascular bundles. Dr. Treub regards the hydrocyanic acid in Pangium edule as one of the first plastic materials for building up proteids; he thinks it is, in this plant, the first detectable, and perhaps the first formed product of the assimilation of inorganic nitrogen. In accordance with this hypothesis, the formation of hydrocyanic acid in Pangium depends, on the one hand, on the presence of carbo-hydrates or analogous products of the carbon-assimilation, and, on the other hand, on the presence of nitrates. These two points were proved, or at least rendered probable, by a great number of experiments made by Dr. Treub in the Buitenzorg Gardens. (The details of this investigation will be found in a paper published in the Annales de jardin botanique de Buitenzorg'). 5. Exhibition of Models illustrating Karyokinesis. Professor Farmer described a set of wax models illustrating the typical forms passed through, and the chief variations exhibited by, the chromosomes during the |