the tree which it affeets to more favourable conditions of development. Mr. Moore, of Sydney, tells me he has seen Lichen-growth disappear from a tree simply by transferring the latter to a richer soil or more favourable locality, or by supplying it with proper manure.

It is inconceivable that there should be such unanimity of opinion among arboriculturists, totally devoid of bias or theory, and expressing only the results of repeated observations in very different quarters of the world, without the existence of some good ground for their assertions. My impression is that arboriculturists are right to a greater extent than are the lichenologists, and that Lichens must be regarded as, in some measure at least, parasitic, drawing the constituents of their thallus from the objects on which they grow. I pointed out in 1856, in my preliminary work on "British Lichens (p. 50), that the filamentous Lichens, belonging to such genera as Usnea, Ramalina, Evernia, and Parmelia, which coat, with shaggy flowing masses, oak, firs, and other trees, and whose growth is the main subject of dispute between lichenologists and arboriculturists, contain such bases as Silica and Alumina, Lime, Potash, Soda, Magnesia, Manganese, and Iron, in combination, or not, with Carbonic, Sulphuric, Hydrochloric, Phosphoric, or other acids. The most of these could not have been derived from the atmosphere; and indeed we are shut up to the conclusion that, as in the case of higher plants, they are derived from the surfaces or substances on which the Lichens containing them grow.* This conclusion is further supported by the recorded facts that chemists have detected iron in greatest amount in species affecting ferruginous soils, and silica in those growing on quartzose rocks, or their débris. I am not, however, prepared to contribute any new facts towards the settlement of the interesting question which forms the heading or title of this communication, or of the other equally interesting, but less practical and economically important questions, which naturally suggest themselves for consideration in connexion therewith. My purpose is rather to call attention to the paucity and unsatisfactory character of the facts or opinions that have hitherto been recorded, and to invite the record of facts as contradistinguished from mere opinions, bearing upon the following points more especially : I. What is the precise ground on which the assertion is founded that Lichen-growth is detrimental to timber and other trees?

* In a paper by the late Dr. Dundas Thomson, of Glasgow and London, on "The Inorganic Food of Lichens” (Edinburgh New Philosophical Journal, vol. xxxvii., 1845, p. 187), he says, "Contrary to the usually received opinion...... Lichens require inorganic matter as part of their food, which they must derive from the localities upon which they are fixed." He points out that the Lichen thallus contains from 5 to 7 per cent. of ash and that the same inorganic constituents are found in corticolous as in saxicolous species.

II. In what way does such growth injuriously affect the timber, bark, fruit, or foliage of such trees?

III. How far is Lichen-growth a cause of unhealthy or diseased development in the trees on which it occurs?

IV. How far is it a result of such development? V. To what extent do Lichens draw their constituents (A. organic, B. inorganic) from the atmosphere?

VI. To what extent from their bases of support, -the bodies on which they grow?

A BOUQUET FROM HELVELLYN. THE top of Helvellyn when fairly reached is chiefly occupied by a sort of mossy plain or table-land, probably once formed of sphagnum, which is now dried up and overrun by smaller and more arid mosses, intermixed with very dwarf specimens of thyme grass and other plants, and here and there stiff close bunches of coralline-like Lycopodium alpinum, and netted with the ropes, often yards in length, of the tough, creeping stems of the Tod's-tails, or Stag-horn (Lycopodium clavatum), which might easily catch the feet and trip up the unwary pedestrian. These two Lycopodiums, and perhaps also the coarser Lycopodium selago, are as fond of exposed barren situations as are some of their congeners, such as Lycopodium undatum and Lycopodium selaginoides of wet sheltered nooks.

But while enjoying a repose on this beautiful mossy height, we must not forget that Helvellyn, in common with most if not all the lake mountains, is really encumbered with quantities of loose stones, apparently disintegrations constantly going on from the effects of weather on the slaty cleavage of the fundamental rocks, starting up in places completely denuded, far above the surface of the mountain, and adding so much to the savage grandeur of the scenery, as, for instance, "Striding edge," ending in the fine precipices round the Red Tarn. These detached pieces of rock, by whatever ancient or modern agency they may have been shivered off from the general mass, roll or slide down the sides of the mountain, helped on by the winter snows and torrents and the summer thunderstorms, their course, however, generally guided by some inequality or furrow-like depression of surface; and here gliding down, they collect from the dews and rains imperceptible rills of moisture underneath them, which serve as nurseries for many of our choicest and loveliest sub-alpine plants. I do not mean to restrict my bouquet solely to Helvellyn, because on Fairfield, Loughrigg, Oxenfell, Dunmail Raise, and other adjacent and similar localities, I have found the very same plants, and many more than I can venture to load the pages of the GOSSIP

The

with the mere names of; but I may be allowed to specify a few, whose intrinsic beauty and their rarity, except in favoured mountain districts, must attract the interest of observant ramblers. feathery tufts of the Parsley-fern (Allosorus crispus) seem to delight in sporting themselves on the highest and driest stones, as if they disdained to seek their nourishment from aught but the atmosphere; yet round the lower edges of the stones on which they grow, and below the barren Parsley-cut fronds that surround the more upright fertile ones, there may frequently be found beautiful mosses, sometimes even the glowing golden Apple-moss (Bartramia Halleriana), and other of the Bartramias, with their conspicuous globular fruits, whose presence sufficiently indicate the presence of moisture. Lower down, and in damp soil, are rosettes of thick unctuous leaves, curled round their edges, and sending up three or four slender stalks, each bearing a nodding-flower something like a violet; this is the Pinguicula or Butterwort, so called from the greasy feel of its leaves-and hence its French name of Grassette. On somewhat drier ground

grows the little Fairy Auricula, with its lilac flowers and powdered leaves and stem (Primula farinosa), and little Polygalas, both blue and white and pink; and the twining fumitory (Fumeria capreolata) throws its elegant garlands round two or three pieces of loose rock, as if it would bind them together with its fragile links. Sparkling in a bed of moist moss, we see a cluster of gem-like leaves, each set round with a number of brilliant rubies, and each ruby set on a slender trembling hair: this is the exquisite Sundew (Drosera rotundifolia, or longifolia). Their small upright spikes of white flowers are not very conspicuous-but see, growing near, a kindred plant with large shining white flowers, each on its slender stalk raised some inches above the crown of dark, heart-shaped, green leaves round the root: this is the Grass of Parnassus (Parnassia palustris), and it is difficult to convey in words an idea of its beauty, the milky opal of its petals being daintily traversed by veins-of the most delicate chrysophrase green; and at the bottom of each petal is a fleshy scale, fringed at the edge into fine rays, and each ray tipped at the point with a pellucid greenish gland. The rubies of the Drosera are similarly constituted glands, which are confined to her trembling leaves, and disappear in her flowers, whereas in Parnassia they are placed only in the flowers, the leaves and stalks being devoid of glands. Dr. Lindley placed both Parnassia and Drosera in the Saxifrage tribe; and if we pluck any of the numerous Saxifrages which grow scattered among the rocks, and examine the flower, we may see a great similarity in their formation. The constant dripping from the wet mossy bed of these two sister beauties has formed a little pool, almost a miniature Tarn, in the bank; and growing in it is a

small green weed, looking at first sight like some Alga or Nitella, with its finely-cut verticillated leaves; but among them are curious little bottles, which give the name to the plant (Utricularia). These bottles or bladders are filled with air; and, during the growth of the long slender stalks which bear the upper leaves and the flowers, they buoy these up on the surface of the water, so as to keep them dry, until the pollen has been scattered on the ovary and the seeds formed in the Pericarp; then the bladders burst, the plant sinks to the bottom, there to perfect and preserve the seed-vessels till the next season calls forth the new young embryo plants into growth.

Schleiden speaks of the affinity of structure of these little bladders to the magnificent pitchers of the Nepenthes; but our good little bottles remain closed while they are wanted as floats, thus seeming to fulfil the same office as the tender spiral footstalks which uncoil to raise the female flowers of Valisneria above water: the economy of both is identical. The male flowers of Valisneria become detached from their stalks, and rise spontaneously to the surface, thus reminding one of the pretty fable of the powerful Water-Nixei Prince, who floated about so merrily in the sunshine while wooing the fair nymph Valisneria; but the moment she consented to be his bride, he carried her off into the darkness of his oozy palace at the bottom of the lake.

However, we must not diverge so far from the "stones on Helvellyn" as to add to our bouquet the very numerous and curious aquatic and half-aquatic treasures of bogs, marshes, and tarns; but if any readers of this slight sketch should feel sufficient interest in the subject, I would say to them, go and search, not heeding wet feet, torn dresses, or a few scratches and tumbles; for the botany, as well as the geology, of the lake district, is a subject of inexhaustible interest, and the locality teems with pleasant memories, in association with first-rate characters, though so many of them are now, alas, passed away. I am thankful to have enjoyed the great privilege and advantage of acquaintance with some of them.

"It was," says Professor Sedgwick, "near the summit of Helvellyn that I first met Dalton, a truth-loving man of a rare simplicity of manners, who, with humble instruments and very humble means, ministered without flinching in the service of high philosophy, and won for himself a name greatly honoured among all the civilized nations of the earth." The Athenæum remarks, in recording the recent honour paid to his memory in Carlisle,

Cumberland may well be proud of the poor weaver's son, who sent his name forth to the ends of the world as the propounder of the Atomic Theory.'

It was also during the late geologist's rambles

in Cumberland that he became acquainted with Southey, sometimes shared in the simple intellectual pleasures of his household, and profited by his boundless stores of knowledge. "Here also," he says, "I held invaluable communication with Wordsworth, who joined me in many an excursion, and delighted me among the dry details of my own study with the outpourings of his manly sense, and with the beauteous and healthy images which were ever starting up within his mind during his communion with Nature."

There have been men who, after a long poetical communion with the outer world, and imaginative intercourse with the outer glories of Nature, have learnt at length to be idolaters of Nature in a pantheistic sense, bordering on Atheism!-and there have not been wanting men who, calling themselves of the "Wordsworth school," have adopted this perverted and idolatrous dream. But Wordsworth was a man of firm religious convictions, "and many a time," says Professor Sedgwick, "when it was my great happiness to roam with him over his native mountains, have I heard him pour out his thanks, that while he had been permitted to slake his innermost thirst at Nature's spring, he had been led to think of the God of Nature, and never to forget His redeeming love!"

Safe under this belief, surely not only the poetical but most reflective minds, while endeavouring to study somewhat of Nature's wonders, and the course of secondary causes which are ever working out the original fiat of the all-powerful Creator, may delight to trace the constant creative and sustaining influence of that Divine essence which permeates and acts on and in all things, with a "continuity" (to borrow Mr. President Grove's word), which controls and harmonises all, from the "strength of the mountains," built up of the dislocated, torn, twisted, riven, and molten materials of some former condition of the earth! even down to our little friends that spring on its sides, or

IN

The meanest herb and flower That drinks the morning dew!

P. S. BURY.

HELPS TO DISTRIBUTION.

N the course of a walk lately through a shady lane near Bath, I came suddenly upon three or four harvest spiders (Phalangium opilio). As they scampered away, I observed that one of them had a dark object on its right fore leg, which evidently formed no part of its normal structure. On securing my long-legged friend, and examining the object with a lens, I found, to my great surprise, that it was a specimen of Chelifer caneroides, which had fixed itself to the leg, and was holding on "like grim death." Indeed, so tightly was the little creature

attached, that I had some difficulty in making it let go, in order to transfer it to a bottle.

The question at once arose in my mind: What business had Chelifer in such a strange position? It could not be with a view to a dinner; one would as soon expect to see a weasel attack a lion, as a Chelifer seize on a Phalangium. Besides, it had attached itself, not to the part usually infested by parasites, the soft juicy abdomen, but to the middle of the hard dry tibia. As far as I know, the Pseudoscorpions feed exclusively on insects, smaller than themselves, such as Atropos, the Acarina, &c., hence their occasional occurrence among books and papers, where they are of great service to the student.

I am inclined to think that in this little incident is involved a circumstance connected with the life history of the lower animals, which deserves to be more thoroughly investigated. I mean, the method taken by them (or rather provided for them) of transporting themselves from one spot to another.

With regard to the vegetable world, we know that special precautions are taken by the dispersion of seeds, to insure the wide dissemination of plants, and to prevent them from overcrowding and thereby starving each other. A stroll on a fine day during summer will generally show us the pappus of the thistle or dandelion floating high above the ground. Later in the year, we may see the winged samara of the sycamore twisting and twirling through the air, or hear the cracking of the furze-pods, as they expel their contents with a force sufficient to carry the seed a considerable distance. And the chances are, that on returning from our walk, we find our trowser legs bristling with the hooked fruit of the bed-straw and burdock. These, and a thousand similar phenomena are so easy of observation, and the methods employed are so patent, that the veriest tyro in botany must often have had his attention drawn to them. Moreover, the purpose for which these curious contrivances are brought into play, are in all cases the same-viz., 1st, to found new.colonies, far away from the parent plant; 2nd, to prevent the exhaustion of the soil by the too close proximity of plants of the same species, a calamity which would inevitably take place, if the seed were always dropped straight to the ground, as we may see in the familiar instance of the fairyring.

Now why should not laws of a like nature be applicable to the humbler members of the animal world?

The Scorpion tribe generally (and, I suppose Chelifer among them) are blest with "long" families, possessed of huge appetites, but with restricted powers of locomotion. Hungry mouths have to be filled as surely among crustaceans as Christians; and doubtless a healthy brood of Pseudoscorpions, moving, as they can, forwards,

backwards, or sideways, with equal case, will quickly clear a neighbourhood of the minute organisms that go to form their food; this being accomplished, the family, or at least some of its members, must either starve or emigrate. Nature, no doubt, has pointed out to them that the latter is the preferable proceeding, and that the best method of carrying it out is by riding on the back or limbs of some more gigantic relative. Hence the finding of a Chelifer on the anterior leg of Phalangium opilio; for there (had he not been interrupted) he might have passed over in ten minutes, a space of ground, which it would have taken him a week to traverse on his own feeble limbs; and thus, with little inconvenience to his bearer, or trouble to himself, he might be carried to fresh scenes, teeming with the food best suited to sustain him.

No doubt, too, the same mode of locomotion aids in disseminating insects, with a view to the foundation of new colonies. Female ants are supplied temporarily with wings for this purpose. A week or two ago the air in this neighbourhood was filled with female ants, careering across the country in search of suitable spots in which to lay their eggs, and establish new kingdoms. The case of gossamer spiders is familiar to every dweller in the country; the tiny threads on which these animals float from one point to another being constantly seen in the air, often in great abundance.

However, it is to transportation by the aid of other animals that I wish to direct the attention of all who may have witnessed instances of the tinier creatures (not parasites) being carried about by the larger and more quickly moving members of the Animal Kingdom. If such would record their experience, they would materially aid in elucidating an obscure chapter in Natural History.

I

W. W. SPICER.

THE UNITY OF MANKIND. HAVE read with some interest the articles in SCIENCE-GOSSIP on the Unity of Mankind; and to me it seems "F. A. A.," in his reply to Mr. Milton, not only fails to answer his opponent's objections, but departs from several of his former theories and propositions. In his first article he proposes to establish, in place of the complex classifications formerly in use, a simple one founded on colour, and so divides man into three groups,white, brown, and black; brown he afterwards states to be a mere transition-state between white and black, so that in reality we only have two groups or classes-white and black. Simple enough division certainly, but is it satisfactory? A classification, to be scientific, must be based upon some peculiarity or peculiarities which are well marked, and which occur invariably in all the individuals of each different class; but "F. A. A." himself says that

races are always changing their colour, that whites become browns, and browns black when exposed to certain climatic influences; and that, by his own showing, his classification wants the element of stability. Besides, as Mr. Milton has proved, instead of "F. A. A.'s" simple black, brown, and white, we have human beings of many different colours,— yellow, green of various tints, chocolate colour, and brown of every conceivable depth of hue, so that I am afraid, if we took colour as the distinguishing mark, we should have fifty instead of five races of mankind, and this certainly would not be advancing in simplicity from Prichard. Besides "F. A. A.” shows so little confidence in his own system that, in the same article in which he proposes it, he used another which surpasses the colour one in simplicity and correctness when he speaks of Circassians, Moguls, &c., and then he states that the brown Hindu is the only coloured representative of the Circassian race. The fact which he quotes as to children, &c., of the Hindus being white, if true, would only prove, I think, that the Hindus were not a brown race at all, but a white one; for surely he would not attach any scientific importance to tanning from exposure occuring in individuals.

Which is the primeval race? he asks, but does not attempt to answer. From the general tenor of the articles one would think that he considered white the primeval colour, but in the August number, abandoning the charming simplicity of white, brown, and black, he introduces another colour, red, which he thinks may have some claim to be the original one: if so, to what influences are due the extinction of the red, or its conversion into white? If all mankind is descended from one forefather, what was his colour? and will climatic influences sufficiently account for the production of the varied hues of mankind now? May he not have been black? and instead of the negro being a degenerated white man, may we not be improved negroes? If climate can degenerate, can it not regenerate? It may be answered that the Mosaic account teaches differently, but I would say with all reverence that the history in the Bible was written for a peculiar people and time, and should not be imported into scientific discussions at the present day.

In his last article "F. A. A." modifies his argument as to the influence of heat; he says, "I do not believe that heat alone produces a dark skin, but heat, an unhealthy climate, and prolonged isolation will, I think it is impossible to doubt, produce and perpetuate the most marked and extraordinary peculiarities." Would he kindly inform us what nation or body of men have been subjected to these three influences simultaneously, and the peculiarities produced thereby? Certainly colour is not one of these peculiarities, for if we take them separately, heat, "F. A. A.” allows, alone would not make a

white man black'; an unhealthy climate, and by this I suppose is meant a climate unhealthy,to white men, for unhealthy is a comparative term, would certainly produce disease, but the result of disease would more likely be death than a dark skin. As for isolation, it would help to perpetuate any peculiarities which might arise amongst them, but if neither heat nor an unhealthy climate produced duskiness, of course it could not be perpetuated. The influences and effects of the three combined might be expressed shortly in a proposition. Given a community of white men, and subject them to great solar heat, an unhealthy climate, and complete isolation. What would be the effect produced ? Answer: Disease, Death, and Extermination.

This is only one of the many arguments which convinces me that man differs in species, and not in variety only. Is it not more in accordance with the idea of Divine justice to believe that several races of men have been created admirably adapted for the character and circumstance of their places of abode, and calculated to fill their appropriate and necessary place in the grand circle of creation, than that, having created the world for the habitation of mankind, He has so ordered it that a large share of the globe could not be occupied by them till they were reduced to a state of degradation so great as in some cases to make them more resemble the beasts of the fields than their fellow men? I can look upon a Negro not as a blackened and distorted caricature of myself, but as a being created like me to serve a given purpose upon earth, deficient, it may be, in certain qualities, but equalling me in others, and superior, at all events, in this-that he is fitted to inhabit and bring under the sway of man regions where it would be death to me to follow. And I do not believe that any amount of education and training will ever give the negro the intellect of the European any more than it will deprive him of the capability he possesses of withstanding the malarious influences of his native climate.

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SKELETON LEAVES.

R. G.

N a former number of SCIENCE-GOSSIP I encountered a paragraph relative to a question asked by "I. S. S.," who was wishing to know how skeleton leaves are prevented from sticking to the paper by which they are lifted out of the water after bleaching. To this question I can answer with a few words. Skeleton leaves will not stick to paper if they are washed thoroughly in water after removing them from the bleaching liquid; or if oil-paper is used, it is impossible for the leaves to stick to that. Perhaps a few remarks on my simple scheme may be useful, or at least interesting to "I. S. S.," as well as a few more readers of SCIENCE-GOSSIP. Just before the leaves

begin to fall is the season I take advantage of for skeletonizing leaves, simply because at that time the fibrous substance is become tougher and firmer, consequently less liable to break during the process of this tedious and delicate work. I do not use any leaves for this purpose, such ones for instance as the walnut, chestnut, oak, elm, and sycamore, as they contain so much resin, and so would not decay themselves. They also prevent other leaves that are mixed with them from decaying, because the resinous quality in them would effect the water. Herewith I subjoin a list of my choice of leaves and seed-vessels which I gather for skeletonizing. The seed-vessels must be collected just before the seed is ripe. The leaves are those of the orange, lemon, lime, poplar, tulip-tree, magnolia, holly, ivy, box, passion-flower, and moss, and all of the figs. Then I add the calyxes of several plants, as the Nicandra, poppy, Dictamnus, mallow, Campanula, and several others, also a few stalks of flax, hcmp, cabbage, and stinging-nettles. I like to procure a good quantity of each, as that helps the decay. They are all then put into a pan, in which I pour boiling soft water over them. The advantage in using boiling water is that it destroys the vitality and hastens the decay. The pan is then placed in a situation exposed to the sun for about six weeks, frequently stirring it and adding fresh rain water as the other evaporates. By this time the leaves will show some of their fibrous formation; the laxer tissues may be seen partly falling away into the water. I then carefully take them individually out of the water by their stalks, and hold them under the tap of a butt. The stream of water quickly washes away all the remaining fleshy decayed green part, and leaves the leaf a skeleton. They are then placed carefully in some clean water, while the whole bulk is undergoing the same process. Now and then one gives more trouble, being so tender, the force of the water will burst the fibrous substance and make them unsightly; but in the case of a more delicate leaf I generally employ a little piece of board, and holding the two together between my finger and thumb, the stream of water then passes over and through the leaf without breaking it. If there are any that will not yield to this operation without much difficulty, I after carefully rubbing them with the fingers return them to the pan to be soaked a few more days. For bleaching them I procure a hat-box, and across the top I fasten the skeleton leaves by means of strings. A cup containing sulphur is placed at the bottom, which is set on fire. The lid being then shut down, I leave it closed for the sulphur to bleach the leaves, which it will do gradually. I have tried various ways, such as using chloride of lime, and also chloride of soda, which I poured into separate shallow vessels, and immersed the leaves in each for a few minutes. In this way the skeleton leaves may