the others a neutral tint. The tentacles vary much; in one they are of a grass green; in the other three shades of grey and violet specked with white. Two of the latter have a rim of bright crimson round the mouth, and these have the rays of the disc more clearly marked than the others. The largest of the four, which is least attractive in its colouring, stands about five inches high without the column being fully stretched, and more than five inches in diameter of flower. Turning to another branch of natural history, you may like to hear that a Great Northern Diver, in mature plumage, was brought to me alive yesterday. It was found on the beach at Porth Crepa, too weak to make any effort to escape. It was probably driven here from a great distance by the recent storms, for, though it was miserably poor, it refused fresh fish, and died in the morning, apparently of exhaustion. It is twenty-two inches long.-D. P. Alford, Dec. 9.

LATE SWALLOWs.-Hearing, last week, Swallows have been seen on the wing in Norwich and its vicinity, I wished to ascertain the truth of such an unusual occurrence. On inquiry, I found the statement to be correct. A friend of mine informed me that on the 4th and 5th instant he saw them at Carrow and Bracondale, and on the 6th, 7th, and Sth they were circling round the Castle Hill; but their flight in both cases was languid. I can only suppose these birds were hatched too late in the autumn to gain strength enough of wing to migrate with the rest of their companions. Has any correspondent noticed a similar appearance of these birds in any other part of Engiand?-E. A., Norwich, Dec. 11.

PHOSPHORESCENCE OF THE SEA.-In the number of SCIENCE-GOSSIP for November there is an article on the Phosphorescence of the Sea-that when animalcula of any kind are concerned, the light always proceeds from an electrical spark. I do not undertake to say, though I cannot help fancying it does, from many experiments I have made. There is a small kind of Medusa to be found on some parts of the coast, which I have caught sometimes when the sea has been luminous. It is about half an inch in diameter, and of an hemispherical shape, with, I think, five rays proceeding from the centre to the circumference. This shows the light very beautifully, and can be examined in the microscope. By touching any one of the rays, or the part of the body where they are situated, the animal seems to be irritated, and a small spark of light, just like a spark of electricity, is emitted along that ray, and may be repeated at any one of the others. The shape of the animal-a kind of plain convex lenscauses the light at a little distance to illuminate the whole body; but it will always be found to be a sudden spark along one of the rays, and is evidently voluntary, being given out at that part of the body

which is touched, and in colour and appearance exactly resembles a very minute electrical spark, perfectly sharp and distinct, not at all like the light from dead shell-fish.-E. T. Scott.

GUANO AND GUANO-BIRDS. Much has been spoken about the Guano Islands during the last war between Spain and Peru. The three Chincha Islands contain more than 12,000,000 tons of it; the contents of the Lobos, Guañape, and other small islands is not known. From 1841-first year of the exploitation to the 31st December, 1860, the exportation amounted to 4,026,174 tons, valuing 200 million dollars, or average value 10 millions of piastres a year; the exportation of 1864 reached 14 million dollars. The following birds are the great contributors to the produce :-The variegated gannet or Piquero (Dysporus variegatus, Ch. B.); different sorts of sea-gulls, or Gariota (Blasipus Bridgesii, Ch. B. &c., &c.); the Alcatraz (Pelecanus s. Onocrotalus thagus, Wagler.); the inca tern or Zarcillo (Sterna inca, Less.); the Potoyunnco (Pufinuria Garnotii, Less.); the Pájaro niño (Spheniscus Humboldti); different sorts of cormorants, or Cuervos de mar (Carbo cormoranus), (Stictocarbo Gaimardi, Ch. B.), (Hypoleucus Bougainvillii, Less.); the Anhinga (Plotus anhinga, L.), &c.-Bernardin.

BEES AND FRUIT.-The season for collecting honey this year was very short. After Midsummer my bees did not add to their stores. When the fruit became ripe they took the place of the wasps, which are very scarce. I don't remember ever seeing them take to the fruit before as they have done this year, but don't think they obtained any honey from it, or carried any of it to their hives. They most probably lived on it, instead of consuming their scanty stock of honey, keeping that for more pressing times. The quantity of honey collected by each stock has been small in the neighbourhood. The honey-producing flowers did not appear this year as usual; the extreme dryness of last year, I believe, killed them. I found most of my stocks wanted feeding in October, to enable them to stand through the winter. My plan is to make a syrup of 2 lbs. of lump sugar to 1 pint of water; this I place in a feeding pan on the top of the hive, opening the aperture so that only the bees in the hive can get at it. They will take it in freely, if the weather is warm, and store it for winter use. I put some pieces of old comb, which I always keep by me for the purpose, into the pan, to prevent the bees drowning. I was very near losing one of my best stocks this season in feeding them; not having put sufficient comb in the pan, the weather suddenly changed to cold, and the bees ceased to take the food in. It was quite by chance I went to look how they were going on, when I was very much surprised to find the queen-bee struggling in the syrup and

nearly dead. I was not long in extricating her from her perilous situation, and a little warmth soon revived her; and on restoring her to her loving subjects they immediately began to lick her, and she soon retired out of sight. I never saw the queenbee at the feeding-pan before.-P.P.

GEOLOGY.

THE SHALE HEAP.-What is a shale heap? And what possible interest does it present worthy the attention of the readers of SCIENCE-GOSSIP? To the first question I answer: A large heap of refuse will be found at all collieries; but the shale heap is only found at those collieries working the low main bed of coal, and is formed principally of the black, slaty stone-hence its name-which immediately overlies the above-mentioned bed of coal, varying in thickness at different collieries in this district. It will be found at Dudley and the Cramlingtons to run about two inches in thickness, although I have fell in with pieces at Newsham Colliery more than four times that thickness. To the second question: The shale heap is interesting to the naturalist and the collector of fossils for microscopic objects. Vegetable fossils will occasionally be met with, but it consists chiefly of fish remains, such as jaws, spines, teeth, scales, and loose bones. For a very obvious reason, jaws and spines are not so readily met with as teeth and loose bones. Some very fine specimens, however, of jaws have been found, varying considerably in the number of teeth attached to them; but when ground and mounted, and examined through the microscope, present a most beautiful and interesting object. In no instance have I found, in my few years' experience as a fossil seeker, among this shale the slightest trace of the impression of a fish; while in the thin dark blue layer of stone, which crops out at the crag near Cullercoats, they appear to be common; the impression found there is planted on the stone in a most excellent manner. But no jaws, teeth, or scales, to the best of my knowledge, are found there. On two occasions, lately, parties of gentlemen from Newcastle and South Shields paid a visit to the shale heaps at Dudley and the Cramlingtons, with leather bags suspended from shoulder, hammer and chisel in haud, splitting and breaking, and splitting again until a bone, tooth, or jaw was found, which was immediately bagged, with as much interest as a disciple of Izaak Walton would creal a member of the finny tribe just drawn from its native element, to the no little amusement of the youngsters, and to the utter amazement of several of the seniors of the colliery village, as to what the gentlemen could want or find among the black stones on the pit heaps, although there are others courteous and willing to assist them whenever they come.-John Sim, miner, West Cramlington Colliery.

OBJECTS IN TUMULI.-Various small objects, entire and perforated, have been met with in tumuli. They are made of different materials, and were chiefly used as ornaments. They might, however, have been sometimes employed for purposes of exchange, as beads are still used in the slave trade in Western Africa. Among Roman remains, as at Richborough, beads and buttons, in various coloured glass, have been picked up in some quantity. The ancient Britons were accustomed to select objects already perforated, as the Dentalium, a cylindrical marine shell, which they strung together to form necklaces-a neck ornament of this kind, with a bronze dagger and clay beads, having been discovered not long since, in a tumulus at Winterbourne Stoke, near Salisbury. In company with Dentalia, joints of the stem of a Pentacrinite, a fossil Echinoderm of the Hampshire chalk, were found in a tumulus near Salisbury; and a Diadema, a fossil Echinus from the chalk, was also found in a barrow in the same neighbourhood. It is now in the possession of the Rev. E. Duke, and, as it is perforated, was doubtless worn by its former possessor to decorate the person. Beads of jet and amber are sometimes found in tumuli. The Orbitolina globularis, a small foraminiferous chalk fossil, often naturally perforated, occurs in drift deposits. They have been mistaken for fossil beads, and were supposed to furnish some proof of man's existence at the remote period of the drift, as the perforations were thought to have been artificially made. The holes, however, when they occur, for there are imperforate as well as partially bored Orbitolinæ, show the natural structure of the organism, and, it is suggested in the catalogue of the Salisbury Museum, may have occurred from the orbitolina having grown around the stem of some marine plant. I am not aware that these small objects were used as ornaments by the Celtic people, although, from their being commonly met with, it is not unlikely that such was the case. The Celts, like other uncivilized races, doubtless availed themselves of any pretty natural objects for personal adornment which came in their way, whether the objects were perforated or not.-J. S., St. Mary Bourne, Hants.

BOTANY.

AN AUSTRALIAN BURR.-A kind of burr, not before observed, is likely to become a pest to the wool-growers in Australia. Dr. Mueller gives the following account of it:-"The plant submitted for my inspection is scientifically called Acaena Sanguisorbe, and is a native of Australia, where it ranges from the southern borders of Queensland to St. Vincent's Gulf. We have no English name as yet established for the plant. The generic word,

‘acaena,' alludes to the prickly nature of the fruit ; the specific, to the resemblance which this plant undoubtedly shows to the British Burnets (Sanguisorba and Poterium). Like its European prototypes, this acaena seems not to possess any really important useful properties, otherwise they are as yet not ascertained. The prickly fruits readily adhere to wearing apparel, fleeces, &c., and are thus easily carried about. To destroy a perennial plant like this where it abounds, I see no other means than ploughing it in."-Ferd. Müller.

COCO DE MER.-(S. G. Vol. I., p. 270.) A doubt is expressed whether the stem of the Lodoicea palm remains quite straight, undisturbed by tropical storms, or is so flexible that trees standing in each other's vicinity strike against each other, making an extraordinay noise. In a very interesting article, on the Coco de Mer, published February, 1865, in the Technologist, by Mr. G. Clark, who seems to have been on the spot, it is said "in strong breezes the plant bend considerably, while their elasticity causes them to wave in the most graceful manner." Of the root, the same writer says:-"The root is in some cases bellshaped, and in other nearly hemispherical and a vast number of rootlets radiate from it in all directions except upwards; these extend to a great distance around it, and form admirable stays to resist the strain which the play of so long a lever subjects them; and so well do they perform their office, that I have never known an instance of a Coco de Mer having been blown down."-Bernardin.

VEGETABLE ORIGIN OF COAL.-Though exhibiting little structure, there is no doubt of the vegetable origin of all coal. In some cases, shells and remains of insects, fishes, and even small reptiles, have been found embedded with coal, but there are no appearances of aqueous deposits of this kind in the substance of the mineral. Evidence of the mode of ac cumulation may no doubt be detected, not only in the position of the innumerable leaves, twigs, and stems of plants, in the neighbouring clays and sandstones, but in the substance of the coal itself. But all kinds of coal have been so greatly altered in their conversion, they have lost so much of various substances commonly present in plants, in addition to carbon; they have become so compacted and are reduced so thoroughly to the condition of a simple mineral, that the absence of vegetable structure cannot be wondered at. It still remains a mystery how coal was formed, or what combinations were necessary to produce it. In most cases, especially in thick beds, it represents a mass of vegetation that must have taken many years, or a large area, to accumulate, but yet in some instances there is proof that it must have been accumulated rapidly. That it is generally associated with certain shales, with ronstones, either in nodules or bands, and with

sandstones more or less compact, and that in moss cases, though not all, it seems to have been accumulated near the mouths of large rivers or low swampy flats, and in estuaries, are facts and inferences that include the results of recent discoveries and investigations in this matter.-Ansted's Practical Geology.

BOTANICAL CONGRESS.-An International Horticultural Exhibition and Botanical Congress is announced to be held in London, in May, 1866. The Congress will be restricted to two morning meetings, when papers, previously printed and accompanied by translations, will be read and discussed. The chair will be taken by M. Alphonse de Candolle, who will deliver an opening address. Dr. Berthold Seemann is honorary secretary to the Congress, to whom any communications should be addressed.

MICROSCOPY.

REFLECTION ON THE RETINA.-During the summer, having the chrysalis of musquito under a low power of the microscope, the part under immediate observation being the eye, which in this state of the creature's existence is simple, I was much pleased and surprised to see the window-frame, and consequently any object presented to the pupa's eye reflected on the retina. The hand with the fingers in motion was beautifully defined. I employed daylight and no condenser, the power not more than eight diameters. I have never seen this mentioned in any work on microscopy, and hope some of your readers may succeed in obtaining a sight of this interesting object.-S., Oporto.

MOUNTING CRYSTALS.-I have been engaged lately with crystalization in connection with the microscope and polarized light. I have only a few hours occasionally to devote to the pursuit at night after business, and I have no doubt a great many other amateur microscopists are similarly situated. It is therefore a great disappointment, night after night, to lose beautiful slides through not knowing in what medium to mount them. For instance, last night I prepared two slides of pyrogallic acid and chronic acid. If I tried to mount them "dry," they absorbed moisture from the air and returned to a liquid state; and in pure," Canada balsam or "glycerine" they dissolved. Could not some one thoroughly experienced and conversant in, and with the matter, prepare a list of salts, and opposite each name put the appropriate medium or mediums for that particular salt ?-W. S.

دو

ALEYRODES.-This is a very pretty object prepared for the microscope by mounting in a dark cell the perfect insect and its pupa case. The Aleyrodes is a tiny white-winged creature, like a small moth, about the size of a large pin's head, found in

clusters under pear-tree leaves, and cabbage leaves. Sometimes they rise in a crowd from the shaken branch or leaf, and settle again as mere dots upon the neighbouring plants. They multiply with great rapidity; one moth will produce 200,000 aleyrodes in twelve generations. Their transformations are very interesting and curious. The little group of eggs is so small that they appear as a mere film of white powder on the leaf. The lava is a flat semi-transparent scale upon the surface of the stem or leaf, having a folded hair-like proboscis, with which it pierces the plant, and sucks its juices, doing considerable injury thereby. The pupa case which is mounted with the perfect insect is like a fairy slipper, fringed with golden dots, or seemingly set with topaz on silver stems; it is open at the top, where the aleyrodes emerged after its brief trance. The moth, which is not a moth, is worth minute examination. When first I saw this pretty little creature, I thought it was the moth of a leaf-roller or leafminer (this was in the early days of my study in natural history), but placing it under the microscope, the wings were not those of a lepidoptera; they had no scales or feathers, were covered with a white mealy dust; it had no long proboscis, and only a short antennæ; the eyes were divided into two sets, on each side; the joints of the feet only two; and from all these signs it could not be a moth. Then I supposed it to be a coccus; but, further examination proved this to be not so, although the relationship is very near. The coccus in the winged state has only two wings, the aleyrodes has four. The coccus has only one joint in its feet, and this insect has two. Also, both male and female aleyroids are winged, whereas the female coccus always remains in a scale-like, quiescent state. The aleyrodes rank amongst the Homoptera or tribe which comprises the green-fly or Apis, the musical Cicada, the strange foreign Lanthorn Fly (Fulgora) and the coccus; but is in the border-land between the Lepidoptera and the Aphides, a connecting link which renders this preparation particularly interesting. - L. Lane Clarke.

HOW TO MOUNT THE PROBOSCIS OF THE BLOWFLY.-The spreading and mounting of the proboscis of the blow-fly is a process which depends for success entirely upon the dexterity and practice of the operator. The head must be taken fresh from the insect, and gently pinched with the finger and thumb between the eyes. The fluids will cause the proboscis to swell, and now is the time adroitly to apply a glass slide, and get the trunk somewhat into position; then, without relaxing the pressure, another glass slip must be gently placed over the expanded proboscis, and the whole put by to dry. When this is accomplished, the operator must return to the attack, and moisten the specimen with clean

water. Now arrange the brushes in their proper places with the needlepoints, and after placing the glass slip over the trunk for the second time, put aside. An American clip may be used to keep the glasses in close proximity, when the whole has been finally arranged. If too great pressure be employed, either in pinching the head, or placing the glasses in the first part of the process, the delicate tissues will be ruptured, and all the labour thrown away. When the mounter is satisfied that the specimen is perfectly dry, he must then, with a sharp microscopic knife, remove the head from the proboscis by a clean cut. The head is by no means to be squeezed by the glasses like the proboscis, but must be kept outside their edges. All he has to do now, is to saturate the object with turpentine, and mount in balsam in the usual manner. In the preparation, frequent recourse must be had to a lens, as the task is a difficult one, needing plenty of care and patience. One of the best of Topping's beautiful slides of this object should be taken as a standard. I have seen the proboscis of the blow-fly prepared after a different plan. I think as follows: The extreme end of the trunk is cut off with fine scissors, and mounted in glycerine, so as to show the spirals as nearly as possible in the natural state. The former mode, though undoubtedly the most effective, hardly gives a true notion of the relative position of the parts. I am not aware that particular instructions are given in any book relative to the preparation of this subject, and I do not know what may be Topping's plan. The above directions are the result of an accidental discovery after many vexatious failures. Experientia docet.-S. M'Intire.

How To MOUNT THE PROBOSCIS OF THE BLOWFLY. In answer to your querist, "T. S.," as to a method of preparing and mounting the tongues of flies, I beg to send the following, which I have found to give good results. Sever the head from the thorax, and gently squeeze it between the thumb and forefinger, when the tongue will be projected out; soak the whole for two or three days in liquor potassæ, and well wash it in clean water; lay the head flat on a slide, and then with a needle and fine camel-hair brush arrange the various parts. Place another slide gently on the tongue so as not to disarrange it, and submit the whole to pressure in a clip until dry. The tongue may then be cut from the head with fine scissors, soaked for about fortyeight hours in turpentine, and mounted in balsam. Too long steeping in turpentine bleaches too much. I may as well state that I have a dozen or so mounted specimens of the tongue and lancets of the drone-fly, which I shall be happy to exchange for other well-mounted objects, or will forward a slide, post free, to any address on receipt of ten postage stamps.-William Fredk. Rogers.

FISH TATTLE.

FISH IN AQUARIA.-Since the communication at page 284, vol. I., I have had an opportunity of seeing two living Sand Lances (Ammodytes lancea) in the aquarium of Mr. A. II. Meyer, of Hamburg. He has had them for some weeks, and at present they are quite well, in a tank measuring about four feet long, two feet broad, and eighteen inches high, with about four inches of fine sand on the bottom. They were got at Kiel, on the Baltic, and are in Baltic sea water, which is much less salt than ordinary sea water, the latter containing about 26 per mil of soluble matters, while the former has only from 12 to 14 per mil, or even less. The fishes pass most of their time buried out of sight in the sand, but as they are known to be always at one particular spot they can be stirred up with a stick, when they swim about for a few moments (generally with their heads towards the light, and their noses to the hinder glass side of the tank), with an uneasy, rapid, wriggling motion, and presently they dash down into the sand with such instantaneousress that they disappear before the subsidence of the little cloud of sand which they raise in the act of vanishing. They have not been seen to eat anything. Nothing else but these two creatures are in the tank, and this, connected with the facts that the tank is in a cool cellar, with a current ever passing through the water, explains the cause of success. My specimens were obtained in warm weather. These fish would not do with sea anemones, as they would be inevitably caught by the latter. The Smelt, too (Osmerus eperlanus), I have now succeeded in keeping better than formerly, but I have it in fresh water not in sea water as before, and in a large, broad, shallow, and cool tank, with a fountain always playing in it. Under the same circumstances, I also maintain the Schnäpel (Coregonus oxyrhynchus), a fish not found in Britain, and belonging to the same genera as the Gwyniad, of Wales (Coregonus lavaretus), and the Vendace, of Scotland (Coregonus Willoughbii). These two fishes, belonging to the same family as the Salmon and the Trout, are difficult to maintain in aquaria, and it is surprising what an apparently small matter affects them. A trifling variation of temperature, a little impurity, or a difference between the oxygenating surfaces of two tanks, is a matter of life or death to them. For example, on placing some Schnäpel and Smelt in a 300 gallon fresh water tank, with a surface of water of 25 square feet and a temperature of 60° F., the fishes turned up immediately, and would have died in a few minutes, but on being transferred to a tank of the same capacity, 300 gallons, but with a water surface of 48 square feet, and a temperature of 55° F., they revived immediately, and are still alive. Yet the amount of water running into both tanks

was exactly the same-ten gallons an hour.-W. Alford Lloyd, Zoological Gardens, Hamburg.

SEIZED BY A PIKE.-I am indebted for the

following to Dr. Genzik:-"In 1829 I was bathing in the swimming school at Vienna with some fellowstudents, when one of them-afterwards Dr. Gouge, who died a celebrated physician some years ago— suddenly screamed out and sank. We all plunged bringing him to the surface, and finally, in getting in immediately to his rescue, and succeeded in him up on to the hoarding of the bath, a pike was found sticking fast to his right heel, which would not loose its hold, but was killed, and eaten by all of us in company the same evening. It weighed 32 lbs. Gouge suffered for months from the bite."Pennell's "Book of the Pike."

PILCHARDS IN MELBOURNE.-From politics to pilchards is not a change of topics more sudden and abrupt than was the arrival about a month ago in our bay of immense shoals of this beautiful and nutricious little fish. They were a novelty in our waters, and they came in such prodigious numbers that one shoal is described (by the captain of a vessel sailing through it) as not less than three miles long. They were caught in tons, and sold about the streets of Melbourne at sixpence a bucket full. As the drought has caused butchers' meat to be very dear at present, these fish were welcomed as a timely supplement to the table, and the butchers of Williams' Town memorialized the borough council praying that the fishermen should be compelled to use nets of a larger mesh, that the new competion might be eased off to the memorialists. During the last few days, however, these fish have been dying in millions in the bay, and will probably soon disappear as suddenly and mysteriously as they came.-Melbourne Correspondent of the Times.

SHORT-FINNED TUNNY (Thynnus brachypterus).— This fish is a native of the Mediterranean, where, perhaps, it is equally common with the Tunny, with which it appears to have been confounded until distinguished by the discriminating examination of Baron Cuvier. But it appears to be less a wanderer into the ocean than that fish, and there is no record of its having been caught in the British Seas until the summer of 1865, when an example was discovered among the numbers of small mackerel taken near Mevagissey, in Cornwall, in the drift nets, and sent to me by Mr. M. Dunn, an intellegent fisherman of that place. This first example was obtained on the 8th of August, and it is worthy of notice that within a week afterwards a specimen was taken at Polperro, and in September three others at Mevagissey.-Couch's British Fishes.