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SOCIETY FOR PROMOTING CHRISTIAN KNOWLEDGE.

MANUALS OF ELEMENTARY SCIENCE.

A Set of Elementary Manuals on the principal Branches of Science.
Fcap. 8vo., limp cloth, Is. each.

NOW READY. NEW and REVISED EDITION, with Additions.

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By ROBERT BENTLEY, Professor of Botany in King's College, London.

The following Volumes of this Series have already been published :—

ELECTRICITY. By Professor FLEEMING JENKIN.
PHYSIOLOGY. By F. LE GRos Clark.

GEOLOGY. By the Rev. T. G. BONNEY, M.A., F.G.S.
CHEMISTRY. By A. J. BERNAYS, Ph.D., F.C.S.
CRYSTALLOGRAPHY. By HENRY PALIN GURNEY,

M.A.

ASTRONOMY. By W. H. M. CHRISTIE, M.A., F.R.S.
ZOOLOGY. BY ALFRED NEWTON, M.A., F.R.S.
MATTER AND MOTION. By the late J. CLERK MAX-
WELL, M.A., &c.

SPECTROSCOPE AND ITS WORK (The). By RICHARD
A. PROCTOR.

LONDON: Northumberland Avenue, Charing Cross, W.C.; 43, Queen Victoria Street, E.C.; 26, St. George's Place, S.W. BRIGHTON: 135, North Street.

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A MONTHLY ILLUSTRATED MAGAZINE. WORLD.

"A Grand Effort to popularize Science."-Kettering Observer.

A PRIZE OF TWO GUINEAS

Will be given for the best short account of the lives of ANY TWO of the following well-known Naturalists:

HUGH MILLER

CHARLES DARWIN

AGASSIZ
LINNÆUS

WILLIAM SMITH
CHARLES WATERTON

No Essay must consist of more than 800 words in all, not more than 400 to be devoted to each naturalist. Envelopes should have "Prize Competition" marked on marked on the outside, and should

be addressed to-The Editor of The Naturalist's World, Ilkley, Yorkshire.

Competitions must be sent off so as to reach the Offices of "The Naturalist's World,” not later than February 15th.

Full particulars of this Prize will be found in the January number, post-free from the Editor for 2d. in stamps.

OF ALL BOOKSELLERS.

seems to indicate that the deposit is of ancient origin, and this is further confirmed by the appearance of the Diatoms; although no new genus has been observed, and not more than three or four new species. Many of the forms have an old world look, and exhibit minute differences from those of more recent times.

As this deposit will perhaps become better known, and, as before observed, access to Herr Grunow's original paper is somewhat difficult, I propose giving a list of the new species and varieties, and figures of three of the most remarkable.

Cymbella abnormis, var. antiqua, Grun.; C. austriaca, var. prisca, Grun., var. excisa, Grun.; C. gastroides, var. neogena, var. dubrávica, var. crassa, C. lanceolata, var. cornuta; C. sturii, Grun.

S. intermedia, Grun.; S. brevistriata, var. subacuta, Grun.

Surirella clementis, Grun. Valve linear-lanceolate, gradually constricted towards the apices, slightly cuneate; alæ almost obsolete; canaliculi marginal 9 in. oor"; centre of valve with a slightly elevated ridge or median line not reaching the apices, and terminating in short and sometimes curved spines. Length of valve, 0040 to 0048; greatest breadth, 0012" to '0015"; breadth at centre, '0006" to '0008". This very remarkable form approaches in general appearance very near to the genus Cymatopleura, but a careful examination shows that its proper position is in with the Surirellæ. The inflations so conspicuous on the frustular view of the species of the former genus are absent, and in their place alæ

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Fig. 40.-Epithemia cistula, 90.

OOOR

Fig. 41.-Staurosira Harrisonii,
var. amphitetras.

Epithemia cistula (Eh.) var. lunaris, Grun. Valve arcuate, ventral margin slightly rounded opposite the turgid dorsum; ends produced slightly inflated; costa distant; irregular striæ moniliform. Length, *0020 to 0030.

Herr Grunow considers this form to be a var. of Ennotia cistula (Eh.). I have examined Ehrenberg's figures of this species (of which there are several in the "Microgeologie"), but cannot see any resemblance between them and the above-named variety.

Navicula nobilis (Eh.) Kg., var. neogena, Grun. ; N. viridis, Kg., var. semicruciata, Grun.; N. impressus, var. semicruciata, Grun.; N. modesta, Grun.; N. decurrens, var. Eh. var. subsolaris, Grun. ; N. haueri, Grun.; N. radiosa, var. dubravicensis, Grun.; N. gastrum, var. styriaca, Grun.; N. clementis, Grun.; N. tuscula (Eh.), var. ornata, Grun.; N. elliptica, var. grandis, Grun.; N. ventricosa, var. truncatula; N. informe; N. crucicula, var. protracta; Peronia antiqua, Grun.

Staurosira Harrisonii, W. S. var. amphitetras, Grun. Frustule linear, valve quadrangular; sides concave; apices produced, rounded; striæ costate; length of sides '0015, fig. 2.

This charming little form is rare in the deposit. The type form is, however, common.

Fig. 42.-Surirella clementis, 90.

may be detected, and also a spinous median line. This species is not uncommon in the deposit. Synedra ulna (Ehr.); S. delicatissima, W.S.; S. familiaris, Kg., var. neogena, Grun.

Nearly all the Synedras are more or less distorted, apparently caused by pressure, and not by any teratogenic influence exerted during the development of the frustules.

Norwich, July, 1884.

Ν

A FREEZING MICROTOME.

IN reply to E. Lamplough, I have tried many forms

of freezing microtomes while working in the Strassburg laboratories, and got by far the finest sections of soft tissue by using the one described below, which was made from descriptions of one which I am told is in use in Dr. Klein's laboratory. The freezing vessel consists of a small wash-tub, twelve inches diameter, by three and a half inches deep. Get a cover made of wood on which is cemented a plate-glass top with a hole cut in the centre, one and three-quarter inches in diameter; out of this hole projects slightly a brass or iron grated top (on which the tissue is frozen), this top rests on a hollow pillar screwed on to the bottom of the tub, and this pillar is honey-combed with holes, to give free access to the freezing mixture with which the tub is filled, viz., ice and salt. The microtome is made on the principle of a joiner's hand plane, and consists of a metal frame (brass is best) to hold three large and fine threaded screws, A, B & C, which are

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to talk about them to my neighbours, one of whom showed me a bed of double stocks raised from the seed of a solitary plant with single flowers, which, growing in an isolated spot, had probably received no pollen from the flowers of other plants. Here and there a plant with single flowers might be found among the lot I saw, but, besides being comparatively few, the plants bearing single flowers were small and weakly. The next gardener that I saw showed me two zonal pelargoniums with double flowers. He said that he had raised those plants from seeds, the produce of a single flower, with which he had not interfered, nor did he think that any insect had

He had found three ripe seeds

cross-fertilised it. and sowed them. They all germinated, but one seedling plant had died. The other two grew to maturity, and each of them bore double flowers. Thus we see how double flowers appear on plants under cultivation without conscious effort on the part of the happy gardeners who raise them. When a plant appears which pleases its owner more than others he takes the seed from that particular plant and sows them apart from other seeds. If the plants raised from such seeds are grown together, so that their flowers inter-cross, the effect of such inter-crossing is not like that of crossing freely with other plants not so nearly related, but tends to fix any character by which a variety may be distinguished from the species. Florists often keep apart the seeds of such a plant as they like best, having first been careful that its flowers should not be crossed. So, without knowing or intending it, they make arrangements for the appearance of double flowers. A striking difference appears however between the solitary plant with double flowers occurring among a lot of seedling sweet williams and the two plants of zonal pelargonium, each having double flowers, with no single flowered seedling by their side. If the theory of Mr. Mott be right, it would not be likely that so many double flowers would appear among the offspring of a young plant like Mr. Sim's sweetwilliam as among those of an older plant under similar conditions. Now it is well known that zonal pelargoniums are extensively propagated by cuttings which retain the character of the individual plant from which they are taken, and survive for many years to be like Moses in his old age, when the natural force of his strength was not abated. If the flower of such a plant be fertilised by its own pollen, or by that of another flower on the same plant, or on any plant derived from a cutting of the same stock, nothing would be more likely than that plants grown from seed so generated would bear double flowers, as it seems they do. If Mr. Sim's sweet william be kept for so long as it may live in a state of isolation, so that its flowers be not crossed with strange pollen, it would be interesting to know whether the plants raised from its seed would bear an increasing number of double flowers as the plant grows old.

JOHN GIBBS.

CURIOUS CONDUCT OF PIGEON.-My attention was called to a rather novel bit of Natural History on Monday 6th January. It was in the conduct of a pigeon playing and splashing on the water, enjoying itself as if it was in its natural element. The same thing occurred on Tuesday and Wednesday. When it was startled it rose with perfect ease and flew back to its loft. I can testify to its having been the same pigeon on all three occasions. Can any readers assign a reason for this occurring ?-A. W. Fry.

L

ZOOLOGICAL NOTES FOR 1884.

OOKING over my last year's notes, I find one or two which may be worth preserving. My knowledge of the literature of the subject is not large enough to enable me to judge of their general value.

(a.) Late in the summer, the vital fluids of insects seem to become inspissated, in the same way as those of leaf-petioles. Hence they may be touched when at rest, before able to summon sufficient energy for flight.

(6.) During the summer, I observed in some marshy ground by the upper Thames that an atrous Limax was attached profusely to the stems of a rush, whose black flowering spike was distantly similar. Is this mimicry, and if so, to what end?

(c.) On February 15th, after a fire, for the first time since the autumn, had been alight an hour or two in a room, a blow-fly emerged from its pupa-case, and stayed in the room for four days, although doors and windows were constantly open. The cold air would seem to have formed an impenetrable barrier.

(d.) Out of an incomplete brood of P. rapae, which perfected early in May, were the last to emerge, and the first, the percentage of ♂ was 22, and in the course of a confinement of some two or three weeks, all of them died, without having made any attempt at coition, the surviving hardily. This would point to ♂ as the subjected factor in lepidopterous social life.

(e.) A lepidopterous larva, not full-grown, having been inadvertently kept in an air-tight box for 24 hours, commenced to pupate, with the apparent object of preserving its life. When released, and placed with its food-plant, it still proceeded with the work of pupation. Bees confined under similar circumstances having died, it would appear that larvæ respire less abundantly than perfect insects, and pupæ less still, if at all. Also that, when the process of pupating has begun, some internal rearrangement of the larval parts takes place at once (cf. development of spinnerets), as a result of which larval growth cannot be resumed.

(f.) An unfortunate ano unintentional experiment with a T. pronuba would show that the asphyxiating property of hydrocyanic acid fumes may be overcome if brought into contact with the poisoned specimen, especially if of robust habit in time. This may serve as a hint to keep up the strength of cyanide bottles, in order to prevent needless cacopathy. Thus this specimen, after being pinned out, was found three days after fluttering in full vigour, its wings being withdrawn from the pressure of the setting slips. Again, a Spilosoma menthastri laid 160–170 eggs after being stifled and pinned out, although this very common phenomenon is no proof of return to consciousness.

(g) Observed a solitary bee on the wing one mile out at sea off the Norfolk coast. It did not secure

the opportunity to rest afforded by the crab-boat whence it was seen. It being comparatively calm at the time, the journey must have been to some extent voluntary.

(h.) In the end of June a pupa of C. ligniperda broke through its cocoon, which was buried in a flower-pot, worked its way some 3 inches to the surface, exserted the head-parts, leaving the abdominal parts of the case firmly embedded in the earth, and emerged in this way. Another specimen, whose cocoon was half-exposed, fixed its pupa case midway in the mouth of the cocoon while it emerged. Neither the uplifted case, nor the half-protected cocoon, was broken or crumpled by the weight of the moth. This is an interesting instance of adaptation to circumstances. ERNEST G. HARMER.

MR

NOTES ON HYDRACHNIDES.

R. DRAPER'S beautiful illustration of Limnesia reminds one that a monograph of the British fresh-water mites still remains to be written, and therefore a description of the peculiarities of the sub-families Limnesia and Eylais, may be of some interest to the readers of SCIENCE-GOSSIP. These mites belong to Koch's second division Hydrachnides, and with regard to Limnesia, he says, "They are to be found in large and small pools, tolerably common, swim quickly without soon tiring, and are the richest in species of all the four-eyed water-mites." He describes twenty species: of these Hermann had previously described two, and Müller three. The mite Koch takes as his type of the species is Limnesia fulgida, and is, I believe, the one figured by Mr. Draper. The body is oval, smooth, very convex, of a beautiful, somewhat transparent scarlet colour, varied with darker markings produced by the cæca. Eyes four, in two pairs, each pair rather far apart, but the ocellus of each pair near together, forming an oblong figure thus - :: Palpi and legs blue-the four hind legs are well endowed with long swimming hairs, and the tarsal joint of the hind legs is without claws. All the legs are used in swimming. The sub-family Eylais contains, according to Koch, but five species, and he remarks that they differ very little from each other. Eylais extendens, first described by Latreille, is the type species. The body is oval, but much broader behind than before, only slightly convex; the skin velvety; the colour vermilion. The eyes are placed rather near together, forming almost a square thus―:: and are arranged on a plate of chitin or thickened skin. The palpi and legs are of the same colour as the mite; the last pair of legs has no long swimming hairs, consequently when the mite swims, these legs are not used, but dragged after it, in a peculiar and very characteristic manner, which alone, at once

distinguishes Eylais from all other mites; the hind tarsi also have claws. The differences between these mites are therefore sufficiently marked and numerous. They differ in the shape of their bodies, in the texture of their skin, in the position of the eyes, in the form of proboscis and palpi, and notably in the structure of their hind legs. The genital plates of Limnesia are also very characteristic; they differ in the various species, and will no doubt, when better known, be aids of great value in their discrimination.

When Eylais extendens is kept in an aquarium, cr even in a wide-mouthed bottle, it lays large quantities of eggs of a brilliant scarlet; these produce a minute six-legged larva, not in the least like the parent mite; they are very active, running about apparently with equal ease on the glass or on the surface of the water, and no doubt become parasitic; but I have not yet discovered what is the host, although I have had scores of the eggs hatched at various times. With regard to the parasite of Dytiscus, I have been able to keep the beetle in an aquarium until the mite reached the next stage, when it detached itself from its host it belongs to the sub-family Hydrachna, which is distinguished from all other Hydrachnidæ by having a long proboscis, almost, or quite, as long as the palpi. C. F. GEORGE.

A

THE FOUR-SPINED STICKLEBACK.
LTHOUGH it is well known that the four-

spined stickleback, as well as many other fresh and salt water fish, is in the habit of building nests, it may interest some of your non-scientific readers if I give a short account of one which I have in an aquarium. Before I begin, I may mention that the individual to which I refer is darker in colour, and has the lower jaw more elongated than any of the others I have, and I believe is a male fish. He had not been twenty-four hours in the tank before he began to collect the finest fibres of roots, and to weave them among the fronds of a small hart's-tongue fern, and, after incessant labour for two days, he had constructed a beautiful nest about the size and shape of an elongated walnut. Having made the exterior, he then lined it with still finer material, until it was quite opaque, and at length put the finishing touches to it by crawling (I can call it by no other term) all over the outside until it was perfectly smooth. Having finished it to his satisfaction, he sallied forth to seek for a wife, and having set his affections on a female heavy with spawn, he chased her for half an hour, when having succumbed to his attentions, they swam quite slowly together up to the nest. Here they remained for a minute or two, when he put his mouth to her gill, and he appeared to lead her to the entrance, into which she went, and settled down into the nest. How long she would have remained there I know not, but, unfortunately, he bit her tail,

which was projecting out, and she left the nest; and although he has been incessant in his attentions to others, he has not again been able to induce another one to enter. His time is occupied when not chasing other fish, in repairing the nest, constantly pulling bits out, and taking fresh material to it. Whenever he has been inside himself, his whole body stiffens and quivers with excitement. He is very pugnacious and jealous, and if an unfortunate caddis-worm or "boatman " comes near, he carries off the former bodily, and generally manages to frighten off the latter. Two stone loaches are objects of his particular hatred. If this simple account is worthy of a place in your valuable journal, I shall feel obliged if you will insert it. A. H. SMITH.

IN MONTIBUS SANCTIS.*
JOHN RUSKIN-LOQUITUR.

TIS strange my form of scientific thinking

Upon the public fails to bite or hold;
My name with Art it ever will be linking,
Obdurate, deaf, to other truth, it's told.
Oft have I sought the Geological Society,
Of which I've been a Fellow for so long.
My great discoveries shook its cold propriety,
It treats
me with neglect-'tis shameful—
wrong.-

For with a little clay, and sand, and sugar,
The earnest student soon may make a trial;
And, in two jiffeys with some lugger mugger,
Learn geologic truths unknown to Lyell.
Oh, vain and foolish men, they cannot tell
How grew the stone on aldermanic finger,
Yet on "catastrophes of chaos" dwell

Or on the earth's creation longer linger.
For one and sixpence spent upon my teaching,
They'd learn how mountains crystal folds

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