ROYAL BOTANIC SOCIETY OF MEETINGS AT THE GARDENS, REGENT'S PARK, 1872. EXHIBITIONS OF SPRING FLOWERS.-Wednesdays, March 13th, April 10th, May 8th. AMERICAN PLANTS.-Daily, May 27th to June 15th, at 9 o'clock. MUSICAL PROMENADES.-Every Wednesday in May, June, and July, excepting the Exhibition days, commencing May 15th. LECTURES.-Fridays at 4 o'clock. May 17th, 24th, 31st; June 7th, 14th, 21st, 28th; July 5th. ANNIVERSARY MEETING.-August 10th, at 1 o'clock. Now ready, imperial quarto, price £1. 11s. 6d., With 61 Woodcuts and 12 whole-page Plates, containing 99 figures coloured to nature, A Monograph of the Gymnoblastic or Tubularian Hydroids. BY GEORGE JAMES ALLMAN, M.D., DUBLIN AND OXON., This Work contains the result of many years' study, and is intended to work out as exhaustively as possible the general Natural History of the HYDROIDA. A very large proportion of the observations are entirely original, and nothing has been taken for granted which it was possible to subject to personal verification by constant and widelyextended explorations of the coast, both within the tidal zone and in the deeper sea regions, followed up by laborious microscopic investigations. The plates are all drawn by the Author himself from the living animal. The soft parts, which constitute the chief interest in these wonderful organisms, are represented as they show themselves while the animal is still beneath the waters of its native seas. The plates, moreover, contain numerous anatomical and embryological details, and besides the magnified drawings of each species, in every case a figure of the animal in its natural size. LONDON: ROBERT HARDWICKE, 192, PICCADILLY, W. THE MONTHLY MICROSCOPICAL JOURNAL, Published Monthly, price 1s. 6d. No. XXXIX., for MARCH, 1872, contains: ANNIVERSARY ADDRESS TO THE ROYAL MICROSCOPICAL THE ADVANCING POWERS OF MICROSCOPIC DEFINITION. By Dr. Royston-Pigott, M.A., Cantab., F.C.P.S., F.R.A.S., M.R.I., F.R.M.S., &c. THE AMERICAN SPONGILLA, A CRASPEDOTE FLAGEL- A FEW ADDITIONAL REMARKS ON THE EXAMINATION With Reviews of Books and Summary of Microscopical Progress at Home and Abroad. Now ready, in Cloth, price 10s. 6d., Vol. VI. of the above, 388 pp., and 19 whole-page plates; also Vols. I., II., III., IV. and V. may be had in Cloth, price 10s. 6d. each. MIMICRY LONDON: ROBERT HARDWICKE, 192, PICCADILLY, W. THE POPULAR SCIENCE REVIEW, No. XLII., JANUARY, 1872, price 2s. 6d., contains: OF PLANTS. By Dr. W. Bennett. Illus trated. EXPERIMENTAL RESEARCHES ON THE CONTORTION OF ROCKS. By L. C. Miall, F.G.S. Illustrated. THE SUN. By R. A. Proctor, B.A., F.R.A.S. Illustrated. MR. CROOKE'S PSYCHIC FORCE. No.2. By J.P. Earwaker Complete Sets in Numbers, £5. 2s. 6d.; or 10 vols. in Cloth, £6. 3s.; half-morocco, £7. 13s. LONDON: ROBERT HARDWICKE, 192, PICCADILLY, W. LABORATORY, 60, GOWER STREET, BEDFORD SQUARE, W.C. MR. HENRY, is in all R. HENRY MATTHEWS, F.C.S., is prepared to give Instruction in all Branches of PRACTICAL CHEMISTRY, The Laboratory is open daily, except Saturday, from Ten to Five o'clock; on Saturday, from Ten to One o'clock. Mr. Matthews is also prepared to undertake ANALYSES of every description. For Particulars and Prospectuses apply to Mr. Henry Matthews, at the Laboratory, 60, Gower Street, Bedford Square, W.C. Illustrated by 250 Drawings from Nature by TUFFEN WEST. New Edition, much enlarged, with full Description of the various Parts of the Instrument. Fcap. 8vo., cloth, with Illustrations on Stone and Wood, price 2s. 6d. Being a Popular Guide to the Use of the Telescope as a means of Amusement and Instruction. Adapted to inexpensive Instruments. By R. A. PROCTOR, B.A., F.R.A.S. Demy 4to., cloth, price 58. HALF-HOURS WITH THE STARS. A PLAIN AND EASY GUIDE TO THE KNOWLEDGE OF THE CONSTELLATIONS. Showing in Twelve Maps the Position of the principal Star-Groups night after night throughout the Year. With Introduction, and a separate Explanation of each Map. True for every Year. By R. A. PROCTOR, B.A., F.R.A.S., Author of "Half-Hours with the Telescope." LONDON: ROBERT HARDWICKE, 192, PICCADILLY, W. DR. LANKESTER ON FOOD, AND ON THE USES OF ANIMALS, in Relation to the Industry of Man. A Course of Lectures delivered at the South Kensington Museum. By E. LANKESTER, M.D., F.R.S., F.L.S. Crown 8vo., cloth, pp. 750 "Full of sound science, curious anecdotes, and quaint illustration. Dr. Lankester has a singular power of illustrative keenness; and in the discursive lessons which he delivers on so many subjects, there is an overflowing wealth of minute collateral information which is always brought to the level of the last achievements of science."-Lancet. THOMAS ROSS, OPTICIAN To H.M. the Queen; H.R.H. the Prince of Wales; H.R.H. the Princess of Wales; H.R.H. the Duke of Edinburgh; the Royal Navy; the Royal Yacht Squadron; the Prussian, Italian, and Egyptian Governments, &c. &c., 7, LATE WIGMORE STREET, STREET, CAVENDISH SQUARE, (Manufactory, 2, FEATHERSTONE BUILDINGS, HIGH HOLBORN.) In this very convenient and useful Lamp, the distance between the Carbon points is regulated by a self-acting Electro Magnet. From six to twelve cells will give a light applicable for throwing a disc on the screen, or showing the leading effects in Spectrum Analysis. It is well adapted for Exhibiting Photographs on a large scale. Circular, for stamped envelope. Price of Lamp £2. 2s. Grove's Platinum Battery per Cell, 10s.; Bunsen's 5s. JOHN BROWNING. Optical and Physical Instrument Maker to Her Majesty's Government, the Royal Observatory, and the Observatories of Kew, Cambridge, Utrecht, &c., 63, Strand, W.C., and 111, Minories; Factory, 6, Vine Street, London, E.C. NEW MICROSCOPE APPARATUS. LIGHT CORRECTOR. This piece of apparatus is made as shown in the diagram, and consists of a brass plate to lay the object on, and beneath it a wheel which can be turned freely so as to bring the different glasses underneath the specimen. No. 1 is an open space; No. 2 a dark blue glass; No. 3 a light blue, and No. 4 a ground glass. By these a beautiful softness and purity of light can be obtained giving great comfort to the eyes and clearness of definition, entirely obviating the unpleasant yellowness of artificial illumination. Price 78. 6d. Superior Finish, 9s. 6d. CHARLES COLLINS, 157, Great Portland Street, London, W. Catalogues on application. HOW'S MICROSCOPE LAMP, 10s. 6d. Description on receipt of One Stamp. MAGIC LANTERNS, DISSOLVING VIEW APPARATUS, &c. JAMES HOW, 2, Foster-lane, London. DOLLOND & CO., BY APPOINTMENT, OPTICIANS TO (ESTABLISHED 1750.) HER MAJESTY, To the Hon. Corporation of the Trinity House. To the Royal National Life-Boat Institution. HAVE REMOVED FROM 59, ST. PAUL'S CHURCHYARD, TO No. 1, LUDGATE HILL, CORNER OF ST. PAUL'S CHURCHYARD. MANUFACTURERS OF MICROSCOPES, TELESCOPES, OPERA GLASSES, MARINE BINOCULAR GLASSES, BAROMETERS, THERMOMETERS, SEXTANTS, &c. DOLLOND'S UNRIVALLED ONE-GUINEA OPERA GLASS, of great power and clear definition. Dollond's Binocular 2-Guinea Field Glass (the Gem), of great power. DOLLOND & CO.'S Celebrated GOLD, SILVER, STEEL, and TORTOISESHELL SPECTACLES. N.B.--All goods forwarded carriage free to any part of the United Kingdom. PRICE LISTS ON APPLICATION. COLLECTING AND PRESERVING. No. II.-MOSSES.* By R. BRAITHWAITE, M.D., F.L.S. N making a collection of the vegetable pro. ductions of a country, we find considerable differences in the structure of the various groups of plants, and in the tissues of which they are composed; and hence special manipulation is requisite in dealing with. certain orders. Some are of so succulent a nature, or have a framework so easily disintegrated, that they contain within themselves the elements of destruction, and present the greatest difficulty in satisfactory preservation, while others are so slightly acted on by external agents, that little trouble is required to prepare specimens of permanent beauty. The Ferns and Lycopods, being generally appropriated by the collector of flowering plants, will be treated on with the latter, and following these come the Mosses, to which we will now direct attention, taking the alliance in its broadest sense, as including the three groups of Frondose Mosses, Bog Mosses, and Liver Mosses, or Hepaticæ, all of which are readily collected and preserved, and yield an endless fund of instructive entertainment to the microscopist. But it may be asked, Where is the game to be found? Where are the pleasant hunt * Mr. Hardwicke has arranged to supply a mounted specimen illustrative of the above paper, and of the List of British Mosses now preparing, price Sixpence. No. 87. ing-grounds in which they most do congregate? We answer, everywhere may some species or other be met with; yet, though many are cosmopolitan, the majority have their special habitats, and some their special seasons, both being considerably influenced by the presence of moisture. Collecting. The bryologist has one advantage over the phænogamous botanist, for it is not imperative that mosses should be laid out and pressed immediately; and hence less care is required in collecting them, than is bestowed on flowering plants; the necessary apparatus is confined to a pocket-knife, to remove specimens from stones or trees, a stock of stout waste paper, and a vasculum, or, better still, a strong bag, in which to carry the packets. When collecting the plants, it is well to remove any superfluous earth or stones, or to squeeze out the water from those found in bogs; and then each is to be wrapped separately in paper, and the locality marked outside; or the more minute species may, for greater safety, be placed in chip boxes. On reaching home, if we do not prepare the specimens at once, we must not leave the parcels packed together in their receptacle, or mould will soon attack them and spoil the whole; but we must spread them out on the floor until quite dry, and then reserve them to a convenient opportunity to lay out; as in the dry state they may be kept for years unchanged. It often happens that our line of study is developed by some fortuitous circumstance. A neglected flowerpot in a corner of the garden attracts attention by its verdant carpet of moss, or, peeping over the wall, we see the crevices between the bricks bristling with capsules of Tortula muralis, the redtwisted peristome freshly brought to view by the falling away of the lid, and, taking a bit indoors to submit to the microscope, we are so captivated therewith that we then and there determine to become a D bryologist. Nor is this all that a journey round the garden will disclose: the neglected paths yield other species not less worthy of examination, and old apple-trees are not unfrequently tenanted by mosses. Extending our walks to the commons, lanes, and woods, we may find on the ground and banks, in bogs and on the stumps and trunks of trees, a number of species greatly extending our list, while others again are only met with on the clay soil of stubble-fields; as various species of Pottia and Ephemerum: appearing in October, their delicate texture is developed by the constant moisture of winter, and with it also they vanish, to appear no more until the succeeding season. Travelling yet farther away, we find that each locality we visit yields some novelty: old walls and rocks of sandstone or slate, limestone districts, and above all, a mountainous country, are rich in species we seek in vain elsewhere. Here peat bogs, and rocks dripping with water, ever supplied by the atmosphere, or the tumbling streams everywhere met with, are the chosen homes of these little plants, and thither must the collector resort, if he would reap his richest harvest. Winter and spring in the lowlands, and a later period in the elevated districts, will be found most productive of fruiting plants. Preparation of Specimens.-So rapidly does the cellular texture of the mosses transmit fluid, that, when soaked in water, we see them swell up and expand their little leaves, and in a short time they look as fresh as when growing; hence a basin of water, a towel, and drying-paper are all we require to prepare our specimens for the herbarium. If the tufts are large, we must separate them into patches sufficiently thin to lie flat, and by repeated washing, get rid of adherent earth, mud, or gravel. This is conveniently accomplished by holding the tuft in the palm of the hand, under a tap, and allowing a stream of water to pass through it; then by pressure in the folded towel we remove superfluous moisture and immediately transfer to paper, arranging the plants as we wish them to lie permanently, and placing with each a ticket bearing the name: a moderate weight is sufficient to dry them, as with great pressure the capsules split, and thus the value of the specimens is decreased. It not unfrequently happens that two or three species grow intermixed: these must be carefully separated at the time of soaking, and any capsules required to show the peristome must also be removed before the plants are submitted to pressure. *Examination of Specimens.-We have very much to learn about a moss before we can become masters of all the characters that pertain to it as a specific individual. We must observe its branching, the mode of attachment of the leaves to the stem, and their direction; the form and structure of a separate leaf, the position of the male flowers, and lastly the position and structure of the fruit. For the efficient determination of these we require a microscope (the simple dissecting microscope is amply sufficient), a couple of sharp-edged, triangular needles fixed in handles, and a few glass slides and covers. Having soaked our specimen in water, we lay it on a slide, and by cutting through the stem with one of the needles, close to the attachment of a leaf, we can readily remove the leaf entire, and two or three may be transferred to another slide, and placed in a drop of water under a cover: the same thing may be roughly accomplished by scraping the stem backwards with one of the needles; but in this way the leaves are often torn. By examination of a leaf we notice its form, the condition of its margin, whether entire or serrated or bordered; the presence and extent of the nerve; and lastly, and most important of all, the form and condition of its component cells; and for this a higher power is required. With a 3-in. object-glass and C eyepiece we can observe their form, and whether their walls are thickened so as to render them dot-like; their contents, whether chlorophyllose or hyaline; and their surface, whether smooth or covered with papillæ; for often these points are so characteristic, that by them alone we can at once refer a barren specimen to its proper family or genus. Preservation of Specimens.-This may be discussed under two heads:-1st, as microscopic objects; 2nd, for the herbarium. 1. The parts required for microscopic examination are the capsules and peristome, entire specimens of the smaller species, and detached leaves. The capsules having to be viewed by condensed light, must be mounted dry as opaque objects; and for this purpose I use Piper's wooden slides, with revolving bone cover; and in one of these we may fix a capsule with the lid still attached, another laid on its side, but showing the peristome, and a third with the mouth of the capsule looking upward, a position very useful for the species of Orthotrichum, as we are thus enabled to see the inner |