"BRITISH Wild Birds" from number 1 to 26, both unbound. Wanted, Darwin's "Insectivorous Plants," and "Variation of Animals and Plants under Domestication."-F. Willoughby, St. Paul's Square, Birmingham.

WANTED, Foreign and English beetles, will exchange Foreign and English Coleoptera and Lepidoptera. Will correspond with foreign Coleopterists.-D. Dods, 47 Chepstow Place, Bayswater, W.

BRITISH silver coins, in good preservation of Henry, Edward, Elizabeth, Charles, Anne. Also Roman coins, silver and copper, offered in exchange for flint stone or bronze implements.-R. McAldowie, 12 St. Nicholas Street, Aberdeen.

STAINED Sections of Cobea scandens, Ilex Aquifolium, and several other botanical slides, in exchange for other well-mounted slides. Lists exchanged. J. William Horton, Brayford Wharf, Lincoln.

WANTED one or two examples of bone, shell, or stone fishhooks from South Sea Islands, or the Eskimo or American Indians. Liberal exchange offered in crustacea, mollusca, rocks, or micro-slides of marine objects. E. Lovett, 43 Clyde Road, Croydon.

FOR exchange or otherwise. A fine mahogany, 40 drawer microscopic slide cabinet with panel door, &c., to hold 1920 slides, flat.-F. Lovett, 43 Clyde Road, Croydon.

WANTED, old English coins. Six flakes from the neighbourhoods of Dover and Hemel Hempstead offered in exchange. A coin of the above description, of the value of about one shilling. -B. Piffard, Hill House, Hemel Hempstead, Herts.

WANTED, perfect, correctly named, British and Foreign butterflies, in exchange for some good bulbs of liliums and other hardy flowers, British shells, and a few Paris basin fossils (named).-J. T. R., Spring Cottage, Dee Banks, Chester.

OBJECTIVES wanted of half an inch and higher, and other micro-apparatus to exchange for micro-slides, collections of phanerogams and mosses, or botanical works.-J. Harbord Lewis, F.L.S., 145 Windsor Street, Liverpool.

OFFERED, mountain hare stuffed, new, without case, and SCIENCE-GOSSIP unbound, March to May, 1880, and Aug. 1880 to Dec. 1882: wanted uncommon British mammals, skins or in flesh J. Kelsall, Bail. Coll., Oxon.

WANTED a polariscope for microscope. Will give 5 vols. (1877-81). "Popular Science Review," bound and in good condition.-F. Adams, 92 Upper Alma Street, Newport, Mon.

WELL-blown eggs of golden-winged woodpecker, spotted sandpiper, Leache's petrel, and red-winged starling, to exchange for others not in collection.-Dr. J. T. T. Reed, Ryhope, near Sunderland.

WANTED a good second-hand slide cabinet to hold at least 500. Apply, stating price, or exchange required, to W. Irving, 16 Acomb Street, Manchester.

WANTED the vols. or numbers of SCIENCE-GOSSIP from the beginning to the end of 1872; also any of G. Eber's novels, tran-lated from the German. Will give in exchange good slides, various.-J. J. Andrew, L.D.S. Eng., 2 Belgravia, Belfast.

DIATOMS.-Exchange twelve prepared tubes of diatoms (from different parts of the world), for three well-mounted insect slides.-F. Cresswell DuBois, 15 West Cromwell Road, Kensington.

BOTANISTS and others in all temperate regions are cordially invited to enter into correspondence as to the collecting of bulbous plants with a view to exchange for other similar plants, not indigenous to their districts; or to exchange for Geological, Conchological, and other Natural History specimens.-J. T. R., Spring Cottage, Dee Banks, Chester.

CHESSYLITE, bloodstones, jet, actinolite. wood opal, pyromorphite, specular iron, erubescite, dolomitic limestone, graphite, polished madrepores, practical microscopy by George Davis (new); "Human Race," by Louis Figuier (new). British tertiary fossils.-Wanted fossils from tertiary formations of France, Italy, and Germany. Also rare British and foreign shells.-Miss Linter, Arragon Close, Twickenham.

FOREIGN butterflies, Orn. brookiana, (Sumatra); Morpho. cypris (Bogotá); Mania rhypheas (Madagascar); the three most splendid butterflies known; also wings of brilliant species for microscopic purposes. Rare papilios much wanted for figuring, condition immaterial, over two hundred already figured.Hudson, Railway Terrace, Crosslane, near Manchester.

Two hundred and twenty foreign stamps used and unused. valued at 215. in exchange for entomological apparatus, or good collection Lepidoptera, or Coleoptera.-Thomas Mackie, 162 James Street, Bridgeton, Glasgow.

OFFERED, Rye's "British Beetles," ros. 6d., sixteen coloured plates; wanted, "Common British Fossils," by Editor of SCIENCE-GOSSIP; or what offers ?-T. Brewis, Boro' College School, Rotherham.

OFFERED, Cyclostyle, complete, quarto size. Wanted, equivalent in physiographical or geological books or implements.T. Brewis, Boro College School, Rotherham.

OFFERED SCIENCE-GOSSIP for 1883, new, bound, also "The Mysteries of Creation Solved" (new); also "Six Months on Duty" (new), for works on Astronomy and Natural History.— W. M. H., Alstonfield School, Ashbourne.

WANTED, Vertigo lilljeborgi (West), V. tumida, V. alpestris, V. pusilla and V. minutissima. Other British land and fresh-water shells in exchange.-W. Gain Tuxford, Newark.

DUPLICATES: Atalanta, Io, Cardui, Galathea, Semele, Tithonus, Hyperanthus, Egerides, Alexis, Phloas, Bucephala, Caja, Lucipares, Meticulosa, Oleracea, Fluctuata, Rhomboidarea, Cratægata, &c. Wanted, other Lepidoptera.-F. H. Perry Coste, 15 Bruce Grove, Tottenham, N.

SCIENCE-GOSSIP, wauted the following Nos., 43. 46, 51, 52, 55, 59, 67, 68, 72, 76, 83, 84, 210, 212-216, and for 1865-67, 1883, and 1884. Numerous exchanges, periodicals, books, slides, Natural History specimens, &c.-W. T. Taylor, Seymour House, Keswick.

WILL give chalk, gault, lower greensand, and post-tertiary fossils, also land and fresh-water shells, for British lepidoptera, micro-slides, or books.-A. Beales, 37 Kingsley Road, Maid

stone.

"

WILL exchange parts and first 6 vols. of SCIENCE-GOSSIP for Zoologist," or bird skins in good condition.-J. R. Hewitson, Knowle, Mirfield, Yorkshire.

WANTED, eggs of moths, &c., for mounting.-R. J. Cowling, 47 Dockley Road, S.E.

WILL collect and forward specimens of shells, marine and land seaweeds, and, during the coming season, butterflies from counties Dublin and Wicklow. Lists sent.-John R. Redding, 165 North Strand Road, Dublia.

A FEW micro-slides of archegonia and antheridia of mosses and hepatics to exchange for other good slides; send lists to W. G. Green, 24 Triangle, Bristol.

EXCHANGE offers requested for "Science for All," vol. i. and last monthly parts; "Amateur Work," 3 vols., and last parts; "European Ferns," eighteen 7d. parts; "Cassell's Popular Educator," cost 50s. "Beale on the Microscope' wanted.-H. Ebbage, Halesworth, Suffolk.

WANTED, batches of living Helices aspersa, nemoralis, hortensis, and arbustorum, from different soils; exchange land and freshwater shells.-B. Hudson, 15 Waterloo Road, Middlesbrough.

WANTED, to exchange upwards of 100 species of North American eggs, all side-blown, in complete clutches, with full data, for clutches of eggs on British list. Correspondence solicited by-W. Wells Bladen, Stone, Staffordshire.

EXCHANGE for other land or freshwater, fine Anodonta anatina, A. cygnus, Unio pictorum, U. tumidus, Unio sp. America, Paludina vivipara, Limnea auricularia, L. stag nalis, Helix pomatia, H. aspersa, P. corneus.-James Ellison, Stecton, Leeds.

WANTED, to exchange "Knowledge," vol. v., January to June, 1884, for the "Postal Microscopical Journal," 1884.J. B. J., 145 Highbury New Park, London.

WANTED. first seven numbers of "Knowledge," also Nos. 36, 40, 86, 115; will give in exchange micro slides, apparatus, or books. Physiological slides to exchange for others of interest. -W. Tutcher, 22 North Road, Bristol.

SKINS of spotted eagle, male and female; exchange for Iceland or Greenland falcon.-Henry Walton, Birtley, Chester-leStreet, co. Durham.

WANTED, birds' eggs, named and side-blown, in exchange for exotic and British butterflies and moths, also a good secondhand cabinet for birds' eggs.-R. Garfit, Vine House, Alford, Lincolnshire.

WANTED, good material for mounting, more especially insects (in spirit) will give well-mounted slides in exchange.-Charles Collins, Bristol House, Harlesden, N.W.

BOOKS, ETC., RECEIVED.

"The Collector's Manual of British Land and Freshwater Shells," by Lionel E. Adams. London: George Bell & Sons."The Student's Botany," by C. MacDowell Cosgrave, M.D. Dublin: Fannin & Co.-" Medical Annual for 1885," edited by Dr. Percy Wilde. London: Henry Kimpton.-"Cactaceous Plants: their History and Culture," by Lewis Castle. 171 Fleet Street. "Popular Science News" (Boston). "" American Naturalist."-" Report and Proceedings of Belfast Naturalists' Field Club."-" Science.' "Journal of New York Microscopical Society."-" Belgravia."—"Gentleman's Magazine." -Midland Naturalist."-"Ben Brierley's Journal." &c. &c.

COMMUNICATIONS RECEIVED UP TO 11TH ULT. FROM:M. A. M-E. W. O'M.-J. E. R.-F. H. P.-J. A. W.R. W. G.-J. H. M.-R. L. H.-A. B.-E. K. L.-J. S.F. M. P.-J. H.-E. H.-F. S.-H. M. B.-A. W. H.-J. S. C. T. M.-F. W.-D. D.-E. G. H.-C. A. M.-W. I.T. D. A. C.-J. M. B. T.-R. McA.—J. F. C.-J. H. L.J. T. R.-E. B. L. B.-J. B.-E. L.-J. W. H.-Ă. E. H.A. K.-J. E. K.-F. Č.-F. A.-W. S.-J. J. A.-L. C.C. P.-J. T. T. R.-C. F. W.-W. I.-F. C. D. B.-J. H. C. C.-A. A. R.-B. W.-R. C.-W. E. G.-J. T. R.—J. E. L. -H.-A. W. F.-T. M.-T. W. B.-W. M. H.-W. T. T.J. W.-G. M. B.—E. A.-F. H. P. C.-W. G.-A. B.-J. R. H. R. J. C.-H. F.-R. D.-A. H. S.-J. R. R.-A. M. P.G. E. E.-H. E.-F. S.-B. H.-W. H. B.-W. W. B.-J. E. -J. B. J.-W. T.-W. B.-A. H. S.-W. S.-W. O.-H. W. -C. C.-A. E R.-R. G.-C. P. P.-H. S. W.-H. C. C.S. C. C.-&c.

HE' outer "shell"

(if it may be so called), of the eggs of the majority of insects is composed of a chitinous membrane, of such protective toughness, that the eggs are frequently found in the crops of insectivorous birds, mixed with digested portions of food, so intact and unaltered in form, colour, and integrity, as possibly to be found to retain even their vitality. In the article accompanying the plate of the egg of the house-fly in the October 1884 number of this journal, on page 218, an authentic case is referred to, of the eggs of the vapourer moth (Orgyia antiqua) having been found in large numbers in the intestines of a cuckoo, which was captured last August in the garden of the old Charterhouse School, London, and a detailed account of the circumstances published in the "Field" newspaper on the 30th of the same month. The present illustration shows a group of these eggs, after having been extracted, washed, and carefully dried; although the experiment was not tried, it is possible they might have been hatched.

The regularity of the various forms of the eggs of insects, added to exceptional appearances of colour, markings, and even sculptures, render them peculiarly attractive as microscopic objects. As a distinct subject of interest, they offer great diversity and beautyunlike the eggs of birds, exhibiting external appliances, strange structural appendages, fringes of extreme delicacy, eccentric forms and curvatures, with lids, No. 244.-APRIL 1885.

and caps of various devices to aid the omission of the larva.

It is not unworthy of note, that sculptured surfaces of rare beauty, raised nodules, pitted depressions, surrounded with ridges arranged with geometrical precision, radiating from the base to the apex, as found in the eggs of some insects, are peculiarities frequently seen in minute, and isolated germ life, in unicellular plants, the cells of desmids, diatoms, minute seeds, spores, and particularly in pollen granules where external appearances take the most singular and elegant forms.

The collector of the eggs of insects must be guided, in his explorations, by the habit of the parent. The suitable deposition of the egg, and its future development, depend on the supply and position of the food; it would be impossible to conceive an organism in a more helpless condition than a larva just emerged, unless it found itself surrounded by, or within reach of, abundant nutriment; the eggs of all leaf-eating caterpillars are consequently deposited on the branches, and in the interstices of the trees themselves, or in close proximity. Particular trees or plants, probably with some regard to locality and aspect, are selected by different species. In some cases the parent collects and stores the future food, depositing an egg in a cell, and packing it with just the amount required by the larva, anticipating a supply in proportion to the size of the cell which invariably is a sufficient, and an exact, quantity. Many of the vegetable-feeding beetles maintain the preservation of the future progeny by rolling up balls of food, in which is enveloped an egg-a case where the individual is evidently of less importance than the perpetuation of the species, the chances of survival being enhanced by the separate isolation of the egg. It is engagingly interesting to consider the powerful impulses which induce such actions; involving favourable positions, selection of herbage, and often temperature and moisture, as affecting the putrefaction or fermentation of organic substance in which the young maggots may revel, an impulse without doubt emanating from maternal presentiment

E

-for, in many cases progeny are actually nursed and protected by the parent, even supported and supplied with untiring zeal. As a rule insects are only destructive in a larval state-destructive, in many instances, in the sense of being beneficial. In that condition, development is rapid, and the chief business of life, i.e., the preparation for a higher and more important condition, is performed.

In consequence of the minuteness of eggs of insects, and the extraordinary care taken in depositing them, they frequently baffle detection, but it is certain few localities escape, and they may be sought for in the most unexpected, and apparently unlikely places. Many singular instances might be mentioned: the larvæ of the Curculios feed on the developing seeds of plants, the eggs are deposited in the flowers, and during growth, the hatched larvæ bore through the soft tissues of the "receptacle," and devour its contents. In the larger order of the lepidoptera extraordinary care is exhibited, even to the extent of mechanically providing protection by enveloping the eggs in peculiar coverings, or securing a defence with glue-like varnishes of considerable tenacity. The lifeduration of the egg condition, is often a factor. Many moths only deposit on fruits just ripening, a matter of days, and adjustment of time; unripe fruits are never touched. The cocci, or scale insects (infesting peachhouses, and conservatories), fix themselves firmly on the leaves and brood over the eggs; even after death the body forms a tent or covering under which the young remain until mature.

The orthoptera dig holes in the earth and deposit eggs in groups, enveloped in some instances in a case. As in this order the young when hatched immediately exhibit the lively appearance, appetites, and instincts of the parents, and are capable of at once seeking food, a storage of provision, or a contiguous supply is unnecessary. Living and growing tissues are often the nidus and receptacle of eggs. The gad-fly (Tabanus) has a sheath capable of penetrating the skins of animals, and not only depositing the egg, but of setting up a condition of excitement necessary for the future preservation of the young. The means and instruments employed are endless; the various forms of ovipositors is a subject in itself. They are capable of cutting into, and boring beneath the cuticles of leaves or the rinds of fruits, leaving an egg in the parenchyma, with the addition of a corrosive fluid of such virulence as to excite abnormal growths in aid of the sustenance of the future larvæ, producing contortions of tissues, and excrescences, as in the wellknown gall-nut; a curious reciprocity as affecting the functions of the plant, and the requirements of the insect.

Space does not admit the pursuit of this interesting subject; our younger readers must be referred to Kirby and Spence's most charming Introduction to Entomology.

Among remarkable forms may shortly be specified,

the yellow eggs of the cabbage butterfly (Pieris brassica), the puss moth (Cerura vinula), the privet moth (Sphinx ligustri), the transparent eggs of the honey bee, the cockroach, the cricket, and the eggs of most of the parasites, especially those infesting the pheasant. Many of these open longitudinally through well-marked sutures aided by the tension of curvature. For the cabinet, eggs are easily prepared as opaque objects, and it is not difficult to arrange them for observation on the stage of the microscope, in a living condition, showing the movement of the larva within, and with patient watching, its ultimate emergence.

Crouch End.

A

GOSSIP ON CURRENT TOPICS.

By W. MATTIEU WILLIAMS, F.R.A.S., F.C.S. VERY interesting paper on labour and wages in America was read at the Society of Arts by Mr. D. Pigeon, the Hon. J. Russell Lowell in the chair. Among many other facts proving the superior education afforded to artizans there, he showed that the number of public schools in the United States is 225,800, or one to every 200 of the entire population of both sexes and all ages. In Massachusetts alone there are nearly 2000 free libraries, or one to every 800 inhabitants. No wonder then that Mr. Lowell was able to say that "one thing he thought he had noticed in the real American workman, was the amount of brains which he mixed with his fingers," as compared with the workmen of other countries. Now that science is interfering with every kind of industry, this ability to mix up brains with fingers will determine the destiny of nations. Not only the arts of peace, but also the grim business of war, is dependent upon science. The victory of the Germans in the Franco-Prussian war was largely due to the mixing of brain with fingers, in the handling of delicate arms of precision, and the intelligent use of maps by common soldiers.

At the meeting of the Chemical Society, on 19th February, Mr. E. C. H. Francis described a simple but very valuable discovery, viz., that if filter paper be immersed in nitric acid of 1'42 sp. gr., and washed in water, it becomes remarkably toughened without losing its porosity, as when treated with sulphuric acid in making parchment paper. We are told that the paper treated with nitric acid may be washed and rubbed without damage, like linen. It contracts and loses a little weight, but contains no nitrogen. The weight of its ash diminishes, which is an advantage in analytical chemistry, especially in rough and ready commercial analyses where the ash is neglected. As non-chemical readers may not otherwise appreciate the important position held by filter paper in an analytical laboratory, I will explain