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NOTICES TO CORRESPONDENTS.

ALL communications relative to advertisements, post-office orders, and orders for the supply of this Journal should be addressed to the PUBLISHER. All contributions, books, and pamphlets for the EDITOR should be sent to 192, Piccadilly, London, W. To avoid disappointment, contri

butions should not be received later than the 15th of each month. No notice whatever can be taken of communications which do not contain the name and address of the writer, not necessarily for publication, if desired to be withheld. We do not undertake to answer any queries not specially connected with Natural History, in accordance with our acceptance of that term; nor can we answer queries which might be solved by the correspondent by an appeal to any elementary book on the subject. We are always prepared to accept queries of a critical nature, and to publish the replies, provided some of our readers, besides the querist, are likely to be interested in them. We cannot undertake to return rejected manuscripts unless sufficient stamps are enclosed to cover the return postage. Neither can we promise to refer to or return any manuscript after one month from the date of its receipt. All microscopical drawings intended for publication should have annexed thereto the powers employed, or the extent of enlargement, indicated in diameters (thus: × 320 diameters). Communications intended for publication should be written on one side of the paper only, and all scientific names, and names of places and individuals should be as legible as possible. Wherever scientific names or technicalities are employed, it is hoped that the common names will accompany them. Lists or tables are inadmissible under any circumstances. Those of the popular names of British plants and animals are retained and registered for publication when sufficiently complete for that purpose, in whatever form may then be decided upon. ADDRESS No. 192, PICCADILLY, LONDON, W.

F. B.-Your brand is Puccinia Lychnidearum, which is quite different from the wheat mildew.

E. T. S.-In using "immersion" objectives, a drop of water is placed on the lens.

J. P.-The "tick" from weasel does not seem to be different from the Dog-tick (Ixodes ricinus).-W. W. S.

W. R. and G. T. S.-The remains of organisms received were not in a condition to determine with certainty. The red patches in the water as described by you and seen at the docks, with the fragments received, lead to the conclusion that they were a large species of Daphnia (SCIENCE-Gossip, 1866, pp. 156-7).

R. G. A.-We have been informed that a complete list of British Mosses is in preparation, and will shortly be published.

H. C.-Have you seen "Liebig's Letters on Chemistry," or "Johnston's Chemistry of Common Life "? A book on "Chemical Analysis" will be of very little use to one "unacquainted with the principles of chemistry."

C. P. S.-It is Seaside Barley (Hordeum maritimum). W. D. R.-No. 1, the common Weevil (Phyllobius uni. formis), a pretty object for the microscope; No. 2, the still commoner Bracken-clock (Anomala horticola).-I. O. W.

W. H.-All the instruments you require for dissecting flowers will be a pocket-lens (about 1s. 6d.) and a good penknife. You may have a useful little microscope for three guineas. No book of British moths, coloured, can be had at a low price.

W. P. W. S.-Only "Insect Transformations," published nearly forty years ago.

E. A. C.-The query has been answered in SCIENCE-GOSSIP. There is no patent method for finding Triceratum without trouble.

W. R.-No. 2, Atrichum undulatum; No. 3, Polytrichum piliferum.-R. B.

T. H., Jun.-No. 1, Hypnum rutabulum; No. 5, Neckera crispa.-R. B.

J. R. W.-No. 1, Antennaria dioica; No. 2, Salix repens.R. B.

JEMIMA. Hieracium pilosella, very common.

H. B. H.-Cooke's "Fungi Britannici," cent. iii., is just published, and can be obtained at 192, Piccadilly.

T. P. F.-The maple-leaf insect is the curious little Phyllophorus testudinatus of Thornton, the Chelymorpha phyllophora of Clark, and the Periphyllus testudo of Van der Hoeven.-W. W. M. J.-To determine the genus and species of ferns, it is absolutely essential that the fronds sent to us should possess fructification.

C. J. T.-We know of no works on British Marine Algæ superior, if equal, to those by the late Professor Harvey.

WATER-FILTERS.-Referring to inquiries as to purifying water, we would recommend that application be made to the SILICATED CARBON FILTER COMPANY (Battersea) for one of their Illustrated Lists, as these Filters have been spoken of in the highest terms by the Lancet, the Popular Science Review, and the British Medical Journal.

B. T.-It is really quite out of our power to name so many apecimens at a time. We are willing to do all that we can for our subscribers, but this is one of the things that we cannot do. Could not some of our friends think of the Editor, as well as of themselves, when they pack up a dozen "odd things" for him to name for them?

M. B.-A second issue of Mrs. Bury's "Photographs of Polycystius" is in progress, and will soon be published.

A. A.-See Nave's Handybook, just published at 2s. 6d. by Mr. Hardwicke, 192, Piccadilly.

B. R.-We cannot say. Inquire of Mr. King, Portlandroad.

R. S.-In the present number you will find a chapter on Leaf-miners. It is most likely a Dipterous larva which mines the honeysuckle leaves forwarded to us.

EXCHANGES.

GRASSHOPPER-WARBLER'S EGGs for good specimens of Acherontia atropos, Endrominis versicolor, or other good Lepidoptera.-S. H. Hedworth, Dunston, Gateshead.

GUMS, seeds, microscopic objects (mounted, &c.), for fossil teeth and recent or fossil echini.-W. Gray, 16, Crooked-lane, London Bridge, E.C.

LEAF INSECT (Chelymorpha phyllophora) in a living state, or the leaf fungus (Xenodochus carbonarius), for other objects. -J. P. Fernie, Kimbolton.

BRITISH GRASSES (25 varieties) for a similar number of British Mosses, Ferns, or Butterflies.-F. Stanley, Haroldroad, Newtown, Margate.

BLOWFLY (head and tongue mounted), or Campylodiscus clypeus, for other mounted objects.-E. Histed, 3, Great Bourne-street, Hastings.

BRITISH FERNS and varieties, fronds or spores, for others. -J. Morley, Jun., Sherborne-road, Balsall Heath, Birming

ham.

BRITISH LEPIDOPTERA for others in good condition.-For lists, apply to Mr. Brunton, Glenarm Castle, Larne, N. Ireland.

BRITISH FERNS, Mesembryanthemum, Cactus, &c., established in pots, in exchange for shells or fossils.-J. W., 4, Meadow-view, Whitehaven.

EGGS OF LANDRAIL, Lapwing, &c., for exchange.-Lists on application to G. C. Davies, Coneygreen House, Oswestry, Salop.

FISH SCALES (six kinds, mounted) for other objects.-F. S., Post-office, Rugeley.

TROCHILIUM TIPULIFORME and other Lepidoptera for exchange.-A. B. Farn, 5, Ebenezer-terrace, Parson's Mead, Croydon, S.

NYSSIA HISPIDARIA and M. tristata for exchange.-H. Willits, 38, Mowbray-street, Sheffield.

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"A Handybook to the Collection and Preparation of Freshwater and Marine Algæ, Diatoms, Desmids, Fungi, Lichens, Mosses," &c., by Johann Nave. Translated and edited by the Rev. W. W. Spicer, M.A. London: Robert Hardwicke. 1867.

"Summary Notes on Vegetable Anatomy and Physiology, and the Classification of British Plants," by Louis C. Miall. London: Simpkin & Co. 1867.

"A Summary of the Occurrences of the Grey Phalarope in Great Britain during the Autumn of 1866," by J. H. Gurney, London: Van Voorst.

Jun.

"The Technologist" for July, 1867. London: Kent & Co. "The Quarterly Magazine of the High Wycombe Natural History Society," No. 5, June, 1867. Wycombe: W. Butler. "Remarks on Pyrula carica and Pyrula perversa," by T. Graham Ponton. Reprinted from "Annals and Magazine of Natural History."

COMMUNICATIONS RECEIVED.-W. J. B.-R. H.-T. B.— J. B.-W. A. G.-G. T. S.-J. S. T.-B. T.-W. W. S.-J. R. -F. B.-L. H. F.-P. H. G.-A. L.-E. C.-W. G.-C. P. S. -S. S.-E. W.-E. T. H.-F. A. A.-C. L.-A. B.-J. B. K.E. T. S.-J. B. W.-L.-H. E. W.-C. W.-T. P. B.-M. D. P. -H. U.-J. H. M.-J. P. F.-J. P.-A. C. E.-G. C. D.W. T. I.-G. E. B.-E. H.-R. G. A.-F. S.-T. H. H.-K.— H. C.-A B. F.-W. D. R.-B. T.-J. B.-F. S.-J. B. L.— J. M.-G. C. D.-J. W.-Y. D.-W. H.-W. P. (Newark). W. P. W. S.-H. T.-J. B.-J. W. M.-W. M. J.-W. A. L.T. A. H.-W. D.

THE DISGUISES OF INSECTS.

BY ALFRED R. WALLACE, F.R.G.S., F.L.S., M.E.S.

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VERY one has heard of the wonderful Leaf-insect of the tropics, which is scarcely less a puzzle to the scientific naturalist than it is to the natives of the countries it inhabits. I have been told over and over again by intelligent persons in the East of the curious plant whose leaves changed into insects! And I could never convince them that this was not the true explanation, for they would say, "It is no good your trying to persuade me, for I have seen the creature myself;

and I assure you that it has real leaves growing out of it, exactly the same as the other leaves that grow upon the tree." And we really cannot wonder at this belief, for when the creature is alive it remains motionless among the foliage, and the colour, veining, form, and texture of its wing-covers and appendages, are so wonderfully like those of leaves that it is extremely difficult to distinguish it at all.

A few years since a specimen of the Phyllium scythe, the "Walking Leaf" of India, was kept alive at the Royal Botanic Garden at Edinburgh. Mr. Andrew Murray wrote a long account of it, and among other matters says: "It so exactly resembled the leaf on which it fed, that when visitors were shown it, they usually, after looking carefully over the plant for a minute, declared that they could see no insect. It had then to be more minutely pointed out to them; and although seeing is notoriously said to be believing, it looked so absolutely the same as the leaves among which it rested, that this No. 33.

test would rarely satisfy them; and nothing would convince them that there was a real live insect there but the test of touch-it had to be stirred up to make it move, or taken off the plant to crawl on the finger of the attendant."

But these remarkable insects do not stand alone, There are many others in every order which are "disguised" in a somewhat similar manner, some with equal perfection, others less accurately, but all serving the same purpose-that of protecting the insect from the enemies that would destroy it. I propose now to give a short account of some of the more interesting cases that occur both at home and in the more luxuriant regions of the tropics.

Almost every one must have noticed the very different way in which the bright colours are distributed in butterflies and moths. In the former, the whole upper surface of the wings is adorned with equally gay colours, while the under surface is always less brilliant, and is generally blotched or mottled with obscure or simple hues. In most moths, on the contrary, the bright colour is restricted to the upper surface of the lower wings, the upper wings being usually of variously mottled brown or ashy tints. This difference is at once seen to be connected with the habits of the insects, the conspicuous colours being so arranged as to be visible during flight, but hidden in repose. On the other hand, the beautiful mottlings and spots and delicate shadings that cause so many moths to resemble bark or lichens, or leaves or twigs, are never developed on those parts of the wings which are hidden during repose. Thus all the Bombycidæ and Noctuidæ, which conceal their hind wings when at rest, have them either quite plain or ornamented with rich orange or crimson hues; while almost all the Geometrida, which rest with their wings spread open, and such of the Bombycidae as have the same habit, are mottled and tinted alike on both front and hind wings.

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These general facts as to the distribution of colour are the first stage in that process of "disguise" which becomes so wonderfully developed in a few conspicuous cases. The next stage is exhibited by the fact that there is a general agreement between the colour of a large number of moths and the prevailing tints of nature at the season when they appear. Out of fifty-two autumn-flying moths, it has been noticed that a large proportion are of various tints of yellow and brown, so as exactly to match with the "sere and yellow leaf;" while in winter they are of grey and silvery tints, like the washed-out leaves and grass, the fog and the hoarfrost, which give a tone to every landscape at this

season.

We now come to a closer and more special disguise. Many of the moths that rest during the day on palings or on the trunks of trees are marked and coloured so as to match the tints of the bark and lichens, and thus to escape observation. As examples of this numerous class, we may mention two of our commonest species-the "Dagger" (Acronycta psi) and the pretty green Agriopis aprilina. The Lappet moth (Gastropacha quercifolia) when at rest resembles very closely a small bunch of dead leaves; and at a little distance could hardly be taken to be a moth, so curiously does it spread out its hind wings so as to project beyond the others. The accompanying cut (fig. 193) by Mr. T. W. Wood, is an accurate representation of this insect in its attitude of repose.

Fig. 193. Lappet Moth.

One of the most curious of these resemblances is that of the Buff-tip moth (Pygæra bucephala). This insect closes its wings so as almost to form a cylinder; and on the tip of each wing is an oval yellowish spot, edged with a dark brown double line. The wings are greyish and hoary; and the head, again, is much contracted beneath the large thorax, which is also of a buff colour, with a double brown marginal line. The result of this arrangement is that the insect looks at first sight like a

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more of these beautiful adaptations remain to be discovered in our native insects. That most elegant insect the Elephant Hawk moth is of a reddish-pink colour, mingled with dull yellowish-green, and with specks and streaks of white; but it has not been noticed how closely all these colours must assimilate it to the handsome red-flowered Willow-herb (Epilobium), on which the larva feeds, and on which the female insect, while depositing her eggs, no doubt often reposes. The petals of the common Epilobium angustifolium, for instance, are of the same pinkyred as the moth; its stems and seedpods are green, tinted with brown-purple or yellowish, while the white filaments of its stamens correspond to the white lines and streaks on the insect. It is evident, therefore, that while reposing amid a clump of these plants, the Elephant Hawk-moth, although so brilliantly coloured, must be exceedingly difficult to detect, since every part of its body is of exactly the same hue as some portion of the flowers.

We owe the discovery of one of the most beautiful examples of "disguise" in a native insect to the talented young artist and close observer of nature who has furnished the illustrations for this article. He tells us that one fine afternoon in May, being overtaken by a shower, he sought shelter under a hedge, where, among other flowers, the wild parsley (Anthriscus sylvestris) grew in the greatest profusion. While observing the light and elegant forms of these plants, he noticed what appeared to be a small bunch of flowers projecting beyond the rest; and a closer examination led him to the inter

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side as to resemble a dry leaf; and a strong dark line running through the centre of the wings represents the midrib. This species often rests on the ground, on the banks of streams, or on beds of gravel, and depresses the upper wings so much between the lower ones as to form an outline very similar to that of a leaf; and this is no doubt a great protection to it; for although so large and showy an insect, it is very plentiful.

esting discovery that our beautiful little "Orange-orange-red, is so tinted and mottled on the under tip," one of the gayest and brightest of our native butterflies, was reposing among these flowers in such a manner as to gain a complete protection by its resemblance to them. He was now able to see the use of almost every detail, both of the form and colouring of this insect. The bright orange patch, so beautiful when the insect is on the wing, was hidden beneath the hind wings; and there is thus a very good reason for the circumstance that the colour does not extend so far on the under as on the upper surface of the wing, and also for the tip of the upper wings being mottled with green beneath, like the whole surface of the hind wings; for

Fig. 195. Orange-tip Butterfly.

as they are a little longer than the hind wings, the whole form one uniformly coloured surface when the wings are closed (fig. 195). Various other species of Anthocharis, as well as the pretty Zegris of Eastern Europe and our rare Pieris daplidice, are coloured in a similar manner on the under side, though with varying degrees of brilliancy; and it is probable that they are accustomed to repose on the flowers of umbelliferous or cruciferous plants of suitable colours. One of the handsomest species of Indian Pieridæ, the Iphias glaucippe, whose upper wings are ornamented above with a large patch of vivid

By far the most singular and most perfect disguise I have ever met with in a Lepidopterous insect is that of a common Indian butterfly, Kallima inachis, and its Malayan ally Kallima paralekta. I had the satisfaction of observing the habits of the latter in Sumatra, where it is rather plentiful at the end of the dry season. It is a large and showy insect when on the wing; the upper surface being glossed with blue and purple, and the fore wings crossed obliquely by a broad band of rich orange. The under surface of the wings is totally different, and is seen at a glance to resemble a dead leaf. The hind wings terminate in a little tail, which forms the stalk of the leaf, and from this to the apex is a slightly curved dark brown line representing the midrib. The transverse striæ which cross the discoidal cell in many butterflies are here continued so as to form lateral veins, and the usual submarginal striæ on the hind wings, slightly modified, represent others towards the base of the wing. But it is only when the habits of the insect are observed that the disguise becomes manifested in all its perfection (fig. 196). This butterfly, like many others, has the habit of resting only upon a nearly vertical twig or branch, with the wings closed together so as completely to conceal the upper surface. In this position, the little tail of the hind wings exactly touches the branch, and we now see why it is always curved inwards a little; for if it were quite straight, it would hang clear of the branch, and thus fail to represent an attached leaf. There is a little scallop or hollow on the margin of the fore wings at the base, which serves to conceal the head of the butterfly, which is very small for its size, and the long antennæ are carried back and hidden between the folded wings. When sitting on a twig in the manner described, the insect is to all appearance a perfect dry leaf,-yet it is evident that its chances of escape would be much increased if it were surrounded by real dry leaves instead of by green ones; for if, when pursued, it took shelter in a growing bush, it could hardly fail to be still a conspicuous object. Marvellous to relate, it does possess the habit of almost invariably entering a bush loaded with dead leaves, and is so instantly lost to sight, owing to its close resemblance to all the surrounding objects, that I doubt if the most vigilant fly-catcher could detect it. I have myself often been utterly puzzled. I have watched it settle,

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apparently in a very conspicuous situation, a few yards off, but on crawling carefully up to the spot have been quite unable to detect any living thing. Sometimes, while gazing intently, a butterfly would start out from just before my eyes, and again enter another dead bush a few yards off, again to be lost in the same manner. Once or twice only was I able to detect it sitting, and admire the wonderful disguise which a most strange combination of colour, form, and habits enabled it instantaneously to assume. But there is yet another peculiarity which adds to the concealment of this species. Scarcely two of the specimens are alike in colour on the under side, but vary through all the shades of pale buff, yellow, brown, and deep rusty orange which dried leaves assume. Others are speckled over with little black dots like mildewed leaves, or have clusters of spots or irregular blotches, like the minute fungi that attack dead leaves; so that a dozen of these insects might settle on a perfectly bare spray, and clothe it at once with withered foliage not distinguishable from that of the surrounding branches!

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caterpillar of a European moth that feeds on the privet (Hadena ligustri) is so exactly the colour of the under side of the leaf, on which it sits in the daytime, that you may have the leaf in your hand and yet not discover it. In the caterpillars of the Geometridæ, form, colour, and habit combine to disguise many of the species. Those of the Brimstone and Swallow-tail moths may be taken as examples. They have the habit of stretching themselves out obliquely when in repose, attached only by the clasping legs at the further extremity, and will remain stiff and motionless in this position for hours. The little protuberances on the body, their colour and attitude, give them so exactly the appearance of twigs of the living tree, that we may easily conceive the advantage this disguise must be to them; for it is certain that many will escape destruction when more conspicuous insects will be devoured.

Among the extensive group of the Coleoptera, the examples of a protective disguise are literally innumerable. In the tropics, every fallen tree swarms with beetles, and a large number of these so closely resemble the bark to which they cling, that it requires a close examination to detect them. The families of the Longicorns and Curculios furnish the greater part of these; and among the former, that

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