SIMPLE OBJECTS.-No. XIII. α FLOSCULARIA CORNUTA. there is a horn (fig. 129, a), which seems to occupy the place of the sixth lobe, found in some other species. Fig. 129. RUFFLE THIS beautiful little creature, which is one of the large family of Rotatoria, may be found in ponds and ditches adhering to fresh-water plants. It exists in a gelatinous case, so exceedingly transparent, that it sometimes escapes notice, but more frequently its presence is shown by a number of minute Algae and other substances attached to it. When the Floscularia is searching for its food, which consists of the spores of Algæ, and other similar vegetable substances, it stretches itself out of its case, and expands its rotary organ, which consists of a number of long and delicate tentacles spread out in fan-like form from the lobes which surround the mouth. In Floscularia cornuta, these lobes are five in number, and in addition to these These tentacles do not however seem to have any proper motion of their own; their office appearing to be that of forming a cup-like expansion round the mouth, which may serve to guide the food into it. A strong current is observable running into and out of the mouth, caused no doubt by a lining of very delicate cilia, the course of which is shown in fig. 130, c, which represents a section of the mouth between two lobes. "The alimentary canal" is described by Pritchard as "simple and conical, but it is remarkable as possessing a second æsophageal bulb or headthe lower one only having jaws and teeth; two pancreatic glands are present anteriorly." A number of very small round granules are also observable, which within the body lie freely scattered about, but in the tail or foot are gathered into lines, and pass backwards and forwards as the animal moves. When it is about to expand its tentacles, these granules exhibit a swarming motion about the mouth. When it is disturbed the creature retreats into its case, and the mouth is closed so that the tentacles assume a parallel condition (fig. 130, b). The ova are deposited at the bottom of the case around the foot, and contain (as seen by transmitted light), a dark granular mass. As they approach maturity they become of a lighter colour, and the young may be seen moving within the envelope, and having two red eye-spots (fig. 130, d). Fig. 130, e, shows the animal shortly after it has left the egg, having a fringe of cilia round its head, and two eyes, which however disappear as the animal grows older. J. S. TUTE. * History of Infusorial Animalcules, Art. Floscularia. From the same source the teeth (fig. 130, ƒ) are copied. in his neighbourhood, which caused some excitement, I visited the ground, and found the field crossed by a zigzag black line, about a yard in breadth, giving it the appearance at a distance as if a cart had passed through it from which soot had been thrown out in shovelfuls. The caterpillars were not in motion, nor feeding, but basking in the sun, rolled together in thick and deep lumps. I took up about fifty of them by simply putting down my hand. The owner of the land informed me that they had appeared "suddenly," at five o'clock in the morning, on the 28th of April, and that they were then ten times thicker than I saw them, lying just as if they had been emptied out "from pots or bushels." Allowing something for rustic exaggeration, this cannot have been far from the truth; for when I saw them, more than a week after, there were signs of constant dispersion, as I found another body in rapid march across the road adjoining the field, while those remaining were certainly, when I saw them, lying as if they had been emptied out from breakfast-cups at intervals of a few inches. These had moved, on the whole, a distance of two fields from that in which they were first seen. None had ever been observed in the neighbourhood before. From rough estimates I have made since, I think I am within the mark in saying there were at least a million in the remnant I saw in the fields, though I am well aware that this, to some people, may seem almost incredible. I should be glad to know if this is an unusual phenomenon, and how to account for the sudden appearance of such an army. I have never seen or heard of anything at all resembling it. I need scarcely add that the aborigines were greatly terrified, and seemed divided in opinion as to whether it portended war or only cholera.-S. Leslie Brakey, Ennis, Co. Clare, Ireland. Fig. 132. Isthmia enervis x 400. BIDDULPHIA is characterized as having the valve roundish or elliptical, frequently constricted. Frustule compressed, quadrilateral, the corners produced into rounded or horn-like processes, and the ends generally bearing spines. The frustules united into a continuous or zigzag filament. The species selected for illustration (fig. 131) is Biddulphia pulchella. Fig. 133. [The caterpillars received were those of the Greasy Fritillary" (Melitaa artemis), a local species, feeding on the Scabious. One of these we have engraved (fig. 133) from a specimen forwarded by our correspondent.-Ed] CHEMISTRY AND NATURAL PHILOSOPHY. AUSE OF THE ABSORPTION OF LIGHT BY THE CAUSE ATMOSPHERE AND OF THE COLOUR OF THE SKY.-According to observations by Mr. J. P.Cooke, jun., a very large number of the more faint dark lines of the solar spectrum, hitherto known simply as air-lines, are due solely to the aqueous vapour in the atmosphere. From this it results that the absorption of the luminous solar rays by the atmosphere is, chiefly at least, owing to the aqueous vapour which it contains. From observations with his spectroscope of the atmosphere of Cambridge, Massachusetts, he has found that these air-lines increase in number and intensity with the increase in the quantity of aqueous vapour in the atmosphere. The absorption of the luminous rays of the sun by the earth's atmosphere, which is estimated by Pouillet to occur to the extent of a third of the whole passing into it, seems therefore, according to Mr. J. P Cooke's observations, to be due to the aqueous vapour in the atmosphere. The aqueous lines of the spectrum are almost entirely confined to the yellow and red regions of the spectrum, from which it follows that few or none of the blue rays of light are absorbed. The necessary consequence of this is the blue colour of the sky. The setting down the colour of the sky to the absorbent action of aqueous vapour in the air upon the red and yellow rays is in accordance with the fact of familiar observation, that the blueness of the sky is much more intense with the moist air of summer than it is with the dry air of winter. IS THERE OZONE IN THE ATMOSPHERE?-Many of our readers have performed the experiment by which ozone is said to be detected in the atmosphere, namely, that of exposing to the air a slip of testpaper made active by a mixture of starch and iodide of potassium, and observing if it acquires any colour. Now the evidence afforded by this test has been very justly questioned by Admiral Bérigny and M. Frémy, as there are other substances which occur in the atmosphere capable of affecting the ordinary ozone test-papers, and as great irregularity is observed in the results obtained by the use of these papers. M. Houzeau, however, who employs a different kind of test-paper, and one not open to most of the objections which are brought against the ordinary papers of Schoenbein, scems to have established the existence of an ozone-like body, and he has further obtained, by condensing the vapours of the atmosphere, an aqueous liquid having all the properties of oxygenated water. He finds that ozone is always present in the atmosphere in both town and country, and that it is principally formed during the occurrence of storms, hurricanes, and waterspouts, which influence the ozone indications at distances where their existence even remains unknown. D. MICROSCOPY. COLLECTING GROUND.-Amongst the numerous readers of "Science-Gossip," I daresay there are many who have not opportunity to make long excursions into the country in search of microscopic objects. For the information of such, permit me to say, that there are localities in the suburbs of London capable of being reached by a railway trip of a few minutes, and for the trifling cost of a few pence, which during the summer months would well repay a visit. The small pools on Hampstead Heath, for instance, abound with that interesting and beautiful object conochilus, also brachionus pala, and other varieties of Rotatoria, together with volvox globator, and several kinds of desmidiacea. In the well-known Hampstead ponds chara nitellus, remarkable for the facilities it affords of observing sap circulation, grows in abundance. Another locality worth notice is the common at New Wandsworth; the ponds here, formed from old gravel-pit excavations, are teeming with small life. A few weeks since a friend and I took a fourpenny return ticket from Victoria Station to Clapham Junction, from thence a quarter of an hour's walk brought us to the Common. We commenced operations at the pond almost adjoining the enclosure, where once stood the tower built for Rev. Mr. Craig's large telescope, of which nothing now remains but its rusty tube, rotting amidst dirt and rank weeds: here we found large quantities of volvox, red and green hydra, almost every description of fresh-water entomostraca, the smaller kind of caddis-worm, whose beautifully constructed cases, built up of the minutest particles of sand and dirt, and cemented with inimitable skill and precision, defy the powers of our first-class masons to imitate; and a large variety of aquatic larvæ, amongst which was that favourite of the microscopist the transparent larvæ of a small kind of gnat, and that Dahomean savage of the waters the larvæ of the dytiscus, valuable for its fine development of the tracheal process. In a ditch close by, running at the end of several cottage gardens, we collected fine closterium, showing the circulation with a 4-inch objective, Micrasterias and other desmids. In conclusion I may say, New Wandsworth Common is a favorite spot with me; it was here, in a large piece of water near to the railway station known as the "Black Sea," I first discovered, after years of search in other directions, that rare and exquisite polyzoar Cristatella mucedo; and from another large pond skirting the road and opposite the cemetery, I obtained the equally rare and interesting member of the same family, Cristalina lophophus—J. S. PLANT CIRCULATION.-A cyclosis, or circulation of protoplasm, may be very easily seen in the fine rootlets of the common water-weed known by the name of "Frog-bit." A power of from 250 to 300 diameters shows the circulation well.-J. J. R. TOXONIDEA GREGORIANA.-During last autumn I secured several gatherings of diatoms in which T. Gregoriana were more or less present. I obtained them in the outer harbour at Whitehaven a little above low-tide mark. I can furnish a few slides containing specimens, which I shall be glad to exchange for others of value.-B. Taylor, 57, Lowther Street, Whitehaven. DEPENDENCY OF SCIENCE.-No one who attentively examines the progress of any department of science, save such as are (like mathematics or metaphysics) of a purely abstract character, can fail to perceive how much it is dependent upon the perfection of its instruments.-Dr. Carpenter on the Microscope." Fig. 134. A A.. Orifices into which screw the Object-glasses. B. Adapter to Microscope body. C C. Adjusting screws working through the notches x and bearing upon the stud D, whereby exact lateral adjustment can be secured. ADJUSTMENT TO BROOKE'S DOUBLE NOSE-PIECE. -The facility which the original nose-piece affords of rapidly making use of a low or a high power, is, I am afraid, not sufficiently appreciated by the public; but the continuous use of one for some time enables me to imagine that their limited use arises from the piece of apparatus having to be especially adapted to the objectives. It is perhaps necessary to point out that the optical centre of two objectives of different powers may not fall identically upon the same point, not necessarily from any fault in their construction, but because the smallest play in the universal screw will throw it out. The instrument itself, as all microscopists know, consists of a solid bar, with two orifices, into which screw the object-glasses, generally a 1 in. and 4 in., or a 2 in. and in., orin. and in.; but where, in changing the one for the other, the object looked at does not occupy the same position in the field, an adjustment is necessary. To accomplish this two notches are filed in the before-mentioned bar, into which fits a steel stud, against which the bar presses; and as the centre of the object-glass orifices are equidistant, the only adjustment required will be a lateral one, and by filing out one or other or both of these notches, two glasses can be centred exactly. It occurred to me that, by drilling a small hole through each of the notches, and fitting therein a small screw, the filing might be done away with altogether, and any pair of glasses adjusted with very little trouble. This has been done, and the instrument (fig. 134) as altered gives the greatest satisfaction. Two in., two in., two in., or even two in, can be readily adjusted so that an object shall occupy the self-same place in each. For comparison of different objectives, I would point out that this piece of apparatus and its adjusting screws appear to me to be very valuable, and as the alteration, or, I should say, the addition, is very inexpensive, I simply lay the matter before your readers. If necessary, a further adjustment could be fitted by making one of the orifices moveable and sliding in a dovetail, a spring being adapted to force it out; a counteracting screw would then enable any one to obtain perfect centricity should the centres of the objectglass orifices not be equidistant.-J. Bockett. MAKING GLASS CELLS.-The way to make cells out of thin microscopic glass, described in Dr. Carpenter's work, is well known, and after numerous experiments I found that a somewhat similar method could be applied to thicker glass. I procure two pieces of steel, or iron made hard as possible, the size and shape of cell required,-in short, two steel cells the pattern of the glass one wanted, and about one-tenth of an inch thick. I then cut some squares of ordinary window glass the exact size of the steel cells; on each side of a glass square I then, with marine glue, cement one of the steel plates, taking care to have the edges of the two steel plates and glass square all parallel; if the cementing is perfect, a hole may now be made with impunity through the glass by a few taps with the point of a rat-tail file, and enlarged with the file to the size of the holes in the steel plates; heat is then applied to liberate the glass cell from between the steel ones, a fresh square put in, and the process repeated. It is obvious that cells of any size and shape can be made in this manner, and by working with four or five pairs of plates at once a gross of cells may be made in a very short time, at a cost of a few pence-a considerable saving, as glass cells are rather expensive to buy. The same plan will of course answer for making a hole through the centre of a slide. Thin crown or plate glass is easily perforated, and makes a most useful cell. I have tried to cut cells from tube with a cutting saw and emery in a lathe, but the less said of this the better; it can only be done with proper apparatus. -E. G., Matlock. BOTANY. THE MOREL, Morchella esculenta.-A Correspondent having sent us one of these curious looking fungi, desiring to know its name, we have given an Fig. 135. illustration, so that all who may find it in future, may turn it to good account. This is one of the best of the edible specics, and may be dried readily in a current of air, so as to be available for flavouring soups &c., at a season when fresh morels or mushrooms cannot be obtained. We have no poisonous species at all resembling it in appearance, so that when found, it may be eaten without fear. A GIGANTIC MOREL (Morchella crassipes) was exhibited by Mr. W. G. Smith at a recent meeting of the Horticultural Society, which had not previously been observed in this country. It attains a height of from eight to ten inches or more. The substance is brittle and watery, and soon decays. It may be eaten when young, but cannot be dried in the same manner as the common species. The specimen exhibited was found at King's Kerswell, near Newton Abbot, Devonshire, and had a "top" fully as large as an infant's head. A HINT.-Sounder views of the requirements of science ought to satisfy us, that he who can show good reason for expunging a plant from the list of our strictly indigenous species, does some real service towards the attainment of truth, whilst he who needlessly swells his catalogue by the admission of a species on doubtful authority, throws a decided obstacle in its way, and surely doubly puerile is that vanity, by which some are said to have been influenced, who have one year sown the seeds of a rare, or even of an exotic species, in an unfrequented spot, that they might become the earliest discoverers of a new native!-Rev. L. Jeynns. LEGEND OF THE FORGET-ME-NOT.-As told by the Persian poet Shiraz, this story is far more poetical than the German one. "It was" says he, 66 in the golden mornings of the early-world, when an angel sat weeping outside the closed gates of Eden, for he had fallen from his high estate through loving a daughter of earth, nor was he permitted to enter again, until she whom he loved had planted the flowers of the forget-me-not in every corner of the earth. So the angel returned to the earth and assisted her, and they went hand-in-hand over the world, planting the forget-me-not, and when their task was ended entered Eden together, for she without tasting the bitterness of death became immortal, like the angel whose love her beauty had won, when she sat by the river twining her hair with the forget-me-not."-Common Wayside Flowers. STAR OF BETHLEHEM.-The plants noted at page 115, are not the species named, but Ornithogalum nutans. The locality in which they were found was an orchard. THE TULIP. This flower appears to have been scarce at Constantinople, even so late as the middle of the sixteenth century, as in the year 1554, Auger Gislen Busbec (Busbequius) being at the Porte as Ambassador from the Emperor Ferdinand I. of Germany, sent both seeds and the bulbs of the Tulip to Vienna, with an observation that the Turks charged a high price for these flowers, which would not have been the case had the Tulip been then growing spontaneously in that country. -Flora Historica. THE DAISY.-Fabulous history informs us that this plant is called Bellis, because it owes its origin to Belides, a grand-daughter to Danaiis, and one of the nymphs called Dryads, that presided over the meadows and pastures in ancient times. Belides is said to have encouraged the suit of Ephigeus, but whilst dancing on the grass with this rural Deity she attracted the admiration of Vertumnus, who, just as he was about to seize her in his embrace, saw her transformed into the humble plant that now bears her name. HAMPSHIRE BEECHES.-The finest beech-trees in England, are said to grow in Hampshire. The forest of St. Leonard, near Horsham, in Sussex, abounds with noble beech-trees. The cottagers of this forest inform you, that when St. Leonard wished to rest beneath these trees, he was disturbed during the day by the biting of vipers, and that his repose was broken in the night by the warbling of nightingales, and on that account they were removed by his prayers, since which time tradition says of this forest: The Viper has ne'er been known to sting, Phillips. Fruits of Great Britain. |