easily seen; and is, moreover, often quite concealed from view in the hidden depths of the flower. There is no evidence that the honey-secreting flowers are distinguished from the rest by any marks which can guide the bee to them. Bees seem to show by their habits, too, that they have no means of ascertaining the presence of honey, save by actual inspection, for several bees will visit the same flower in succession; and the same bee may sometimes be seen to return to the flower it visited a few moments before, after trying others in the interval.

Again bees often visit flowers without any intention of honey gathering.

It is a bright sunshiny day in the early part of February. Winter aconites have spread forth their yellow blooms, and offer their store of honey to the early bees. A few of the industrious insects are abroad and hard at work. They are rifling the yellow blooms, but not of nectar. Pollen is the object of their search, and the circlet of tiny cornucopias surrounding, the stamens offer their sweet drops in vain. On such occasions it matters not to the bee whether a blossom secretes little honey or much, those with the greatest store will obtain no advantage. Such being the facts, we must, I think, admit that the individuals in the race of flowers which secrete much honey are no more likely to obtain the benefits of cross-fertilisation than those producing little or none. And with this admission the whole theory falls to the ground. The selective action of the bee has not even a theoretical influence as a producer of honey.

OBSERVATIONS UPON THE TURTLE, AND
THEIR ARTIFICIAL PROPAGATION.
By W. AUGUST CARTER, of the National Fish
Culture Association.

URING the Colonial and Indian Exhibition

DURING

specimens of turtle from Western India were shown in the aquarium, sometimes numbering as many as fifty simultaneously. I made a series of observations upon them at the time, and propose to record the result of some of them here.

In the first place, I noticed that the turtle is a somnolent creature, spending a large amount of time in sleep, or repose. They rest at intervals throughout the day, and usually sleep in the early morning, becoming abnormally active at night. When asleep, they lie upon the bottom of their habitat with their heads downwards and eyes closed. At such periods they are not easily disturbed, and appear oblivious to all outward influences brought to bear through the molestation of their congeners. The weight of turtles is considerable, and precludes them from locomoting perpetually in the water; indeed, it seems curious that such awkward creatures have the power to move as rapidly and easily as they do. As a rule, when swimming, they keep near the surface, in order to

gulp in air readily, which they do by stretching forth their head from the water.

Upon land they are helpless creatures, being almost as powerless as the seal under similar circumstances, although there is a decided difference in the formation of their organs. Turtles are able to capture their prey with great agility, being provided with a long neck, which they extend to a considerable degree when seizing it. The head moves quite freely, as well as the fins and tail, which are all quite independent of the shell. Unlike the tortoise, the turtle's head is non-retractile. The former, upon the approach of danger, withdraws its head and limbs, presenting to the aggressor an impervious exterior, proof against the stoutest foe. The house which the turtle carries, however, is a mere shield for the back, and does not, as in the case of a land-tortoise, form a complete covering to the animal. The shell of the former is very light, enabling it thereby to adapt itself to an aquatic existence.

From what I have seen I have arrived at the conclusion, that the turtle is a spiteful, pugnacious, reptile. Extreme examples of this are to be found in young turtles rather than in their elders, as I have frequently seen the former attack the latter, and meet with only a small amount of retaliation. The appearance of two turtles undergoing a pugilistic encounter is highly comical; their utter helplessness rendering the contest all the more exciting. The quarrel sometimes arises from a disputed right of occupying a certain position; when one turtle will jostle another until it retaliates by inflicting blows with its fins upon the head of its foe, which appears to be the most vulnerable part of turtles. Then follow a succession of charges, when they bite and gnaw at one another in the encounter until the vanquished one retires to a remote corner, but only to be attacked again by its enraged congener.

In regard to the artificial reproduction of turtle, there is no doubt that the ova could be hatched if subjected to proper treatment. In their natural state they are deposited by the mother chelonian in the sand, about two feet deep, where they becom.e incubated through the action of the sun. In breeding them artificially nature must be closely imitated, and every detail studied, to ensure success. According to the precepts of nature, I venture to think the following plan might be advantageously adopted. Place the eggs in sand, heated to a normal temperature of 70° from underneath, by the means of hot water pipes. This heat should be perpetually main tained throughout the twenty-four hours. During the day heat should also be concentrated from without, bringing the temperature up to 100°, which could be attained by enclosing the incubating apparatus, taking care to admit a certain amount of air. The sand should be slightly moistened by allowing a small quantity of vapour to descend upon the ova at night-time.

When the turtles break from their shells their first impulse is to seek the water, therefore provision should be made for this, taking care that the water has a temperature of at least 100°. When the ova are shed they are soft, but afterwards become hard, and the progress of formation within can be detected by passing the hand over the eggs, which, at the end of a month, furnish evidences of life. I am inclined to think that, if a suitable incubator was supplied, and the natural conditions of the shelly creatures carefully provided for, they might be reared in this

applaud and support any undertaking having for its object the extensive culture of turtles in Western India and other tropical parts. Their scarcity is due, in a great measure, to the destruction of ova, and their conversion into food, the eggs being highly nutritious.

This wholesale plunder ought to be vetoed by legislative restrictions, more especially on account of their feeble power of reproduction as compared with their finny congeners. Turtles shed a very few ova at one time during the breeding season, but they hatch out with a greater amount of certainty than the eggs

GOSSIP ON CURRENT TOPICS.

By W. MATTIEU WILLIAMS, F.R.A.S., F.C.S. SUGAR REFINING BY ELECTRICITY. -"Electrician" tells us that this is to be carried out by a company in New York, "The Electric Sugar Refining Company," which expects to convert a ton of raw sugar in two hours into perfectly hard white sugar at a cost of 3s. 2d. per ton, and intends to turn out three thousand barrels daily. This is very wonderful indeed, when we consider the bulk of material involved and the cost of obtaining chemical results by electrolysis. The capital stock of the company is a million of dollars. "Electrician" adds, that "the results in this case will be awaited with a good deal of interest; " scientific interest, I presume, rather than interest on the million of dollars.

MATURING WINES BY ELECTRICITY.-The same magazine describes more definitely the work of Sig. Mengarini, who is diligently following up the investigations of Blaserna and Carpine in effecting, by the agency of electricity, those delicate and somewhat mysterious changes which in old-fashioned wines were obtained by years of storage, and at very great cost, that of the compound interest of the dormant capital, rental of cellarage, besides loss by evaporation, &c. Wines are very volatile where many tasting tickets are issued.

We are told that in Mengarini's experiments a current of about four amperes was passed through the wine for periods of varying length; that the platinum electrodes become coated or crusted with a deposit which consists chiefly of albuminous matter; that the proportion of alcohol is diminished; that some oxidation appears to occur; that the bouquet of the wine was developed almost exactly as by age, and was sensibly increased by every application of the current. The colour was also modified and Sig. Mengarini suspects that the wine is sterilised, and thus rendered incapable of further change.

There is nothing marvellous in all this, especially now we know that a moderate heat, skilfully applied as in "Pasteuring," does the like; the amount of energy demanded is very small in proportion to the commercial value of the result; the actions of oxidation, &c., are similar to those which probably occur in ordinary maturation, and, above all, neither Sig. Mengarini, nor Blaserna, nor Carpine are asking for a million of dollars, nor forming any kind of company or syndicate. This removes a mountain of scepticism.

bolts have fallen on the Museum building, neither do the statistics of crime indicate any serious demoralisation of the community since the Sunday opening and Sunday crowding has been in operation.

MUZZLING OYSTERS.-We are told that the late Duke of Wellington despised all pills and potions, that when troubled with small ailments he treated himself by simply "putting on the muzzle," abstaining from food until recovery. This recipe has been successfully applied to oysters which grow sick when packed for exportation by opening their shells, and losing the liquid contained therein, after which the American air enters and decomposition commences. observers have discovered that oysters feed only at about the turn of high tide, and that the habit of opening periodically, persists even when they are out of water. Therefore to keep their shells closed they are now muzzled by means of binding wire passed through a hole near the lip of the shell, then twisted with pliers. This, with practice, is done very rapidly, and the muzzled bivalves survive very long journeys.

This muzzling is but a reinvention, original, doubtless, but not new. It has long been practised by our London fishmongers in the barrelling of oysters for transmission to country places, especially in the old coaching days, when barrels of oysters were customary presents to country cousins. The native oysters were carefully laid in the barrels, and each barrel filled above the level of the top. Then the cover was laid on the oysters and the whole thumped down until all were wedged together so closely that opening was impossible. After this the cover was firmly nailed. Experience proved that the oysters thus tightly packed remained fresh for long periods.

THE PHILOSOPHY OF HANGING.-Dr. Gross, of Geneva, has made some curious experiments which threatened to add his name to the list of martyrs to Science. He constructed a noose which firmly compressed both sides of his neck without pressing on the larynx sufficiently to interfere with his breathing. In two minutes he lost consciousness by congestion of the brain, this congestion being due to the compression of the veins which return the blood from the brain. In another experiment he used isolated compression applied simply to these vessels with like result. He tells us that the loss of consciousness was not preceded by either painful or agreeable sensations (the latter have been affirmed to precede death by hanging); the only feeling he experienced was a sense of warmth or burning in the head. He concludes that the drop of the hangman is unnecessary, and that suicide by hanging may be effectual even when the feet of the victim touch the ground.

Within my recollection London sightseers have witnessed two fatal exhibitions of the wretched trick of imitating the work of the hangman. One was at Cremorne Gardens, the victim, if I remember rightly,

was Blackmore, a celebrated performer on both tight and slack rope, who on several occasions suspended himself by the neck and imitated the struggles of a dying man, but at last performed the reality, and was greatly applauded. The other was Sam Scott "the American Diver," who erected a tall mast on Waterloo Bridge, with a boom on which he performed some antics, and then dived from a fearful height into the river. One of his tricks was an imitation of the popular Monday morning Old Bailey performance, which at last he did perfectly.

It was generally supposed that in these cases the rope slipped and compressed the larynx, but Dr. Gross's experiments suggest another explanation. Had the rope slipped as supposed, the athletic expert, finding himself in danger of suffocation, would instantly have grasped the rope and supported the weight of his body as at the conclusion of his ordinary performance, but if he suffered the gradual swooning described by Dr. Gross, he might insensibly pass the stage of strong effort and slowly die,

POLICE TELEGRAMS.-New York is supplying a lesson in police organisation by adopting a comprehensive system of telegraphic communication between all the police stations of the city. The calls are self-recording, the system of the Herzog Teleseme Company being adopted in preference to the evanescent telephone.

A HINT TO TEACHERS.-All who are practically acquainted with the working of our schools, whether they be what are called " High Schools or Board Schools, or any other schools, will agree with me in concluding, that the microscope is not doing the work there that it should do as a general educator. Too much of mere books, mere verbiage, mere rote work, and too little of direct knowledge generally prevails. Scarcely a school can be found in which the microscope does any teaching at all.

In large schools it is difficult to use an ordinary table microscope, on account of the time that must be consumed in showing objects to the pupils one by one, and the solar microscope or lime-light microscope demands costly arrangements. But I think something might be done by adopting the simple device of giving an occasional collective lesson on some selected object with black-board or diagram illustrations, and then placing the actual object under a microscope (a small cheap one with but moderate power would be sufficient), and allowing the good children to have a peep at the real thing on their way in or out of school. Making such exhibition a reward for good conduct would greatly add to the current valuation of the show, and the general interest in the instruction it would carry. Even where there is no intrinsic interest or pleasure in any act, it acquires a conventional value if it is treated as a privilege or a reward.

This is not limited to children. Full-grown men grumble loudly on being compelled to sit on a jury,

but make huge efforts to obtain the privilege of sitting in the House of Commons.

THE ELEMENTS IN THE SUN.-Messrs. Hutchings & Holden believe that they have found good reason for placing platinum on the list of metals which the spectroscope has found in the sun. They detect sixteen coincidences of the solar lines with those artificially obtained. They confirm the presence of bismuth, cadmium and silver which other observers have considered probable, but are doubtful concerning cerium, lead, molybdenum, veranium and vanadium. They are satisfied concerning carbon, which was formerly described as not found. For reasons I stated in "The Fuel of the Sun," chapter xiii., I doubt the possibility of fairly demonstrating either the existence or the non-existence of the non-metallic elements by means of the spectroscope. During the twenty years that have elapsed since that chapter was written a great deal of spectroscopic work has been directed to such investigation, and the contradictory results that have been obtained, especially in reference to oxygen, confirm my early scepticism. With the thin sharply-defined lines of the metals the case is quite different.

ACTION OF CAFFEINE.-F. Coppola has recently made many experiments on the action of Caffeine on both warm and cold-blooded animals. He concludes that it does not belong to the same pharmacological group as digitalin, because it acts on the heart and the nerve-centres, whilst digitalin and some of its derivatives act exclusively on the heart. He asserts that both strengthen the heart's action by stimulation of its muscular tissue, but they act differently on the frequency of the beat. The chief difference is that caffeine causes dilatation and digitalin contraction of the blood vessels.

Readers of the above should distinguish between "strengthening the heart's action," and strengthening the heart. A stimulant may do the first, but it does not therefore do the second. The reaction following may leave the heart weaker than before. This applies to stimulants generally.

ON

NATURAL HISTORY JOTTINGS.

THE GREEN TORTOISE BEETLE (Cassida viridis). N August 9th, 1881, I for the first time saw the singular larva of the green tortoise beetle (Cassida viridis). It was feeding on the foliage of a thistle that grew on a narrow strip of grass by the wayside. I remarked the canopy of fæces, also the fact of the larva eating out the parenchyma of the leaf from one side, and thus forming rounded spaces, which, from the epidermis on the opposite side of the leaf being untouched, gave a spotted or blotched appearance to the food-plant; in most instances the epidermis was intact over the eaten-out spaces, while

in others it had broken, probably through contraction by the heat of the atmosphere, and had left holes.

In the several accounts of this larva that I had read, in which reference was made to its remarkable habit of supporting over the back canopy-fashion the fæces, these being carried by the two anal or caudal appendages, I never could realise how this skeleton platform might carry such a substance. However, on closely examining the larvæ, I soon saw how this peculiar feat was accomplished, though anything I had read on the subject never led me to suspect it would be so. The manner in which it is accomplished is thus-When the first skin is cast, instead of being thrown off altogether, as is usually the case with growing larvæ, it is retained upon the two rigid whiplike anal or caudal appendages, and upon its upper surface are subsequently deposited the faces which agglomerate, the lateral branched spines of the exuviæ being well adapted for the support and retention of this substance, which is, or shortly becomes, intensely black in colour. When the second skin is thrown off, it likewise is retained upon the anal appendages, and is attached to the first exuvia on the under side by the cast skin of the two anal appendages, which constitutes a compound connecting link not only between these first two exuvia but between each and all of the four that are thrown off before the larva is full-grown ; whilst on the upper surface the mass of fæces, gradually increasing in width and height, agglomerates throughout the entire length of the dorsal covering and protection, which the larva has the power of elevating or depressing: when undisturbed, this covering of exuviæ and fæces lies horizontally over the dorsal region of the larva, canopy-fashion, and more or less completely covers and conceals it from view.

Several of these larvæ I secured, and supplied with their food-plant; and on leaving the country on August 20th, they were shut up in their box, which was not again opened until near the close of September. I then found that all of them had entered the pupa-state, had afterwards fully evolved into the imago condition and hatched out, and were now lying dead on the bottom of the box.

Such were my first few observations and notes on the very singular larva of the tortoise beetle, whilst the desideratum (mentally made) was, further observations thereon. Hence, being again in the same neighbourhood in the summer of 1883, I again searched the thistles in the same spot as before, and in its season found the larva, fed it up, watched its transformations, and made copious notes thereon: these I will give in the order in which they were made, with such additions and modifications as subsequent study of the habits and structure of the larva, pupa, and imago have enabled me to make.

August 11th, 1883.-This evening, at 5.30 P.M., I observed the full-grown larvæ of the tortoise beetle, as well as very small ones, browsing on the leaves of the thistle, at the same place as I observed them two

years ago about this same date. It was very airy at the time and quite cool, there being alternations of sunshine and cloud.

I observe that they eat out the parenchyma of the leaf in roundish small patches from both the upper and under surface, leaving the epidermis in most cases intact above or below, as the case may be. The size of these holes is in proportion with the size of the larva, increasing with its growth; each hole represents a meal, or a course of a meal, and the parenchyma is eaten out by the larva backwardly towards itself with considerable despatch. When feeding, or at rest, the canopy of exuviæ and fæces lies horizontally directly over the dorsal region of the larva, but does not touch it, and extends nearly or completely up to the anterior margin of the thorax, being carried upon the two forward-projected anal appendages. The posterior extremity of the body is turned up at right angles to the anterior and much greater portion; and the anus is at the extremity of the then erect, cylindrical, and telescopic ventral tube, which is of considerable length and situated beneath the posterior margin of the fecal canopy. The fæces are not black when first deposited, but speedily become so; and they consist of both liquid and firm parts. The ventral tube is projected to an extraordinary length on the passage of the fæces, chiefly by an evagination of it, and is applied to the hinder margin of the gradually widening and thickening fecal canopy, and the faces there deposited: this tube, which is in two equal portions fitting into each other, and the body telescope-tube-like, is remarkably flexile, adapting itself readily to the form of the parts to which it is applied, being sometimes bent upon itself at right angles, and at others forming the arc of a circle; and is, sometimes at least, employed by the full-grown larva in pushing off backwardly from the anal or caudal appendages the fecal canopy (which it invari ably does), prior to laying itself up to assume the pupal condition, and also in pushing forwards upon the anal appendages against those that precede it the new exuvial platform, on the shedding of the exuviæ. (To be continued.)

THE DEVELOPMENT OF THE FRESHWATER POLYZOA.

MR

R. LORD'S note in SCIENCE-GOSSIP (Dec. 1887), regarding the development of the freshwater Polyzoa, leads me to suggest the plan, I have for some years adopted, for finding the habitats of these beautiful animals. To the end of my telescopic collecting stick I screw a brass ring about four inches in diameter, to which a very fine cambric net is sown. This net, drawn through the water several times, will secure a concentrated compound of Rotifers, statoblasts of Polyzoa, Volvox, and other organisms too numerous to mention.