teresting. My only aim is to advise the study of Nature.

On the advantages attending the study of Natural History it is superfluous to enlarge; to every one whose heart is well attuned Nature presents a thousand charms.

Fig. 46. Saws and Sheath, seen under pressure, side view, × 60.

So various and manifold are the subjects of Nature's empire, that were the life of one man, however zealous he might be, lengthened out to twenty, nay, a hundred times beyond his allotted term, his materials would not be exhausted; he would still have much to study, much to investigate, and, after all, leave a "Systema Natura" to be enlarged and corrected by those who should come after him. Hence the great advantage of co-operating numbers, each working in his favourite department, and contributing his portion of labour to the public good.

very apparent. We may, nay we must, survey the whole, in order to study a portion to advantage; but while in the one case we content ourselves with a general outline, in the other we follow out the minutest lines, tracing them through all their several curves and ramifications. Every one can, I am sure, do something towards adding to the common stock of information already obtained, even with a moderate degree of attention as opportunity serves. The immense variety of objects which comes under the investigation of a lover of Natural History, so far from discouraging the beginner, should have the effect of stimulating his exertions, as of by far the larger part of "creation" little is comparatively known; nor even of man himself can our knowledge be regarded in any way perfect. And none but those who have tried the experiment can form an estimate of the pleasures which arise from this branch of study. There is a simple pleasure in the acquisition of knowledge, worth to many far more than the acquisition of wealth. There is a pleasure in making it useful to others; there is a pleasure in the contemplation of beauty and harmony wherever presented to us; and is not this pleasure increased when we reflect, as in this branch we become experts, that the sources of them are never-ending, and that our enjoyment of them becomes more and more intense in proportion to the comprehensiveness of our knowledge? And lastly, does not the feeling that we are not investigating the acts of human handiwork, but studying the wonders of a creative design, immeasurably heighten the sources of gratification?

ON MOUNTING IN GLYCERINE JELLY.

SOME

OME of the members of our Postal MicroCabinet Club have asked us how we work with glycerine jelly, and as there seems to be no book which gives a really satisfactory method, we ask for a space in SCIENCE-GOSSIP to detail our plan, which, as it is very effective, and though not quite original is perhaps new to many, we trust will be useful to those microscopists who mount their own subjects. This medium possesses the advantage over Canada balsam that, whilst it renders objects transparent, it does not give them that homogeneous and glasslike appearance which, though sometimes advantageous, often leads one to form a very erroneous idea of the nature of the object. Glycerine jelly may be used for almost every class of objects; and it is, we think, easier to manipulate than any other medium now in use.

To begin at the beginning.-The jelly may be bought at most opticians', but it is very easily made at one fourth of the cost. We have found our recipe as below superior to any given in books:

Soak oz. best amber gelatine (as sold by the chemist or grocer) in 1 oz. distilled water; when it has absorbed all the water, put it in a Florence flask with 50 grains of powdered chloride of barium, warm it in a water-bath and agitate till the barium salt is dissolved. Allow it to cool below blood-heat, and while still fluid add 1 oz. Price's glycerine and a teaspoonful of white of egg; shake until well mixed, replace in the water-bath, and boil at full speed until the albumen completely separates from the jelly in the form of a single lump. Now filter through well-washed fine flannel, and it should be as clear as crystal; but if through mismanagement it be a little cloudy, filter it again, this second time using filter-paper, and placing the funnel with the jelly, &c., in a cool oven. During the coagulation of the albumen, the jelly must on no account be stirred. It is well to beat up the white of egg before use, lest it should be stringy. In lieu of a water-bath a saucepan may be used; and a little salt thrown into the water causes it to boil at a greater heat.

The jelly made after this recipe is of the proper consistency for entomological objects; but for delicate vegetable structures it should be softened by adding to it a third of its volume of a mixture of equal parts of glycerine and distilled water.

Put the jelly into test-tubes inch in diameter, and when you wish to mount a slide, warm the upper part of the tube; in this way you can pour out any quantity free from bubbles. It is perhaps well to put a trace of varnish or some essential oil on the corks, lest they should get mouldy. The chloride of barium prevents fungi in the jelly this is the best preservative we know of, but something is absolutely necessary. By all means avoid putting alcohol, crcasote, &c., in the jelly, as they dissolve varnishes, and also spoil the colour of some objects.

:

We will now proceed to the mounting operations, and will take an insect for the first example.Having dissected the fly, or whatever it may be, put the transparent parts (wings, and perhaps halteres) in a little folded piece of cream-laid note-paper with a drop or two of glycerine, and write the name on the outside, or you are sure to forget the particular insect which they belong to. Soak the opaque parts in caustic potash solution as usual; boil them once, or if necessary twice, in distilled water, using fresh water each time. The objects may now be mounted at once, or kept in glycerine till wanted, and at the time of mounting rinsed in water to remove the glycerine. To mount them, arrange them neatly on a slide, suck away the superfluous moisture through a fine-pointed glass tube; lay on the thin glass cover, and secure with a strong brass clip, or, if the cover be large, use two or more clips. Now drop a little liquefied jelly round the edge of the cover: it will run under, and look too full of bubbles to be good for anything, but that is no matter; just warm it over a small lamp-flame until it boils and

the air is driven out, and when the slide is quite cold it will be free from bubbles, or any bubble left near the edge will disappear in a short time. The jelly must actually boil, but no more. A great many bubbles will be given off before it really boils, but when the heat reaches a certain point the jelly will burst out from under the cover with a slight noise, and the slide should be taken away from the flame immediately. Every now and again you will get a slide so full of bubbles that they will take a week to go away, and perhaps even a second boiling will be necessary; but this is very seldom. After leaving the slide for a few hours for the jelly to set, clean it with a tooth-brush and cold water, carefully wipe it dry, and cement at once with gold size, of which two or three coats should be applied. India-rubber varnish is perhaps better than gold size for the first coat, for the latter cement sometimes runs in and spoils the object; but if it be only laid on thin enough, this will not often happen. Any varnish containing alcohol is worse than useless, because it will mix with the jelly.

The above plan may be applied to palates of mollusks and all animal objects that are not injured by heat. Injections of course would be spoilt by it. Many vegetable objects, such as wood-sections, tough cuticles, and others of a like nature, may be mounted in the same way as an insect, but delicate vegetable structures and objects in cells must be mounted as follows. Air may be expelled by boiling in water, or, in extreme cases, in alcohol, and afterwards washing in water. If that which you wish to mount be such as an alga, you cannot boil it at all, but must merely wash it in clean water, and absorb superfluous moisture with a glass jet.

To proceed.-Drop a little jelly on the centre of a slide, warm it slightly, but not above blood-heat; place the object in the centre; move it gently with a needle to let the jelly penetrate it; lay the eover on quite horizontally-and not one side first, as usually recommended, and when cold clean and varnish. Cells are not often required: only for very thick objects and certain algæ, &c. They may be made of glass, tin, or vulcanite, and should be stuck with marine glue, which is about the only trustworthy cement, or they may be of rings of gold size heated strongly until of a brownish hue. When mounting in a cell, the boiling method is impracticable.

If you wish to use balsam in the same way, after the objects are boiled in water rinse them in methylated spirit, and soak for a time in absolute alcohol; transfer to oil of cloves or carbolic acid (oil of cloves is the better of the two); then lay them on the slide, and mount and boil as above.

For Dammar.-On taking the objects from water, arrange them on a slide with cover and clip, and set it aside till dry; then allow a drop of benzole to run under the cover; about one minute afterwards

During a short stay in Wrexham last summer, I visited with our friends the churchyard of Overton, formerly a village, now a town situated in Flintshire, just divided from Denbighshire by the Dee. The churchyard is planted thickly with splendid yews, and from this circumstance forms one of the lesser wonders of North Wales. I send you a sketch of the church and churchyard, copied from the Art Journal, May, 1873, but it does not do justice to the trees, which are well worth a minute examination. The yews are of various ages: one very old one I examined was fast going to decay, the trunk was quite hollow, and the cavity large enough to hold several people comfortably. As nearly as I could guess (for I did not measure the tree) its circumference must have been 30 feet three feet from the ground.

Again, there are twenty large yew-trees in the churchyard at Gresford, in Denbighshire; but the noted one mentioned in SCIENCE-GOSSIP for April (1873), is a fine specimen. My brother-in-law walked over from Wrexham recently to examine

it for me; he girthed it, and found it measured 29 feet in circumference five feet from the ground; it is more than 60 feet high, and is supposed to be about 1,450 years old, planted in the year 426, when the Romans finally left Britain, Wales being at that time a Roman province.

Both the old sexton and the former churchwarden give a similar account respecting this tree, which several scientific men have been over to Gresford to examine.

In the churchyard of Darley, Derbyshire, there is a very large old yew-tree, which is always a source of attraction to Peak visitors, and is said to be the largest and oldest tree in the kingdom. It measures 33 feet round the trunk, and though bereft of many of its branches, is still in full vigour. In the churchyard, Tisbury, Dorsetshire, there is now standing an immense yewtree, which measures 37 feet in circumference. The trunk is quite hollow: it is entered by means of a rustic gate, and seventeen people lately breakfasted in its interior. One in Staines is upwards of 1,000 years old.

The great yew at Fortingal, Perthshire, N.B., alluded to in Mr. Lee's most interesting paper in the December GOSSIP, 1873, page 265, is stated by Gilpin in his "Forest Scenery," vol. i. page 282, to measure 56 feet in circumference, and is supposed to have been a tree at the commencement of our Christian era. It still remains, and was visited by Mr. Neill, the naturalist, in 1833. This yew is figured by Mr. Strutt.

Many interesting accounts are further given of the yew, in Evelyn's "Silva," and also by Gilpin in his first volume of "Forest Scenery." White, in his History of Selborne, note, page 7, says it is calculated that there are yews in Britain upwards of 2,000 and 3,000 years old.

There are some fine yews round Fountains Abbey, curious in themselves, as well as historieally interesting: they are said to have been full-grown when the abbey was built in 1132. (Gilpin, page 280.)

At Hanchurch, near Newcastle, there is a spacious quadrangle formed by many old yews: a church is once supposed to have stood there. Also there is a remarkable avenue of yews at Hales Hall, near Cheadle, Staffordshire, and again some remarkable yews at Himley, Caverswall, and Tixall. The yew was a sacred tree among the Northerns. Its ancient British name was yw, or ywen; the former (pronounced yew) is the plural, the latter the singular; its botanical name is Taxus baccata.

Evelyn speaks of a holly hedge in his garden measuring 160 feet in length, 7 feet high and 5 feet in diameter. In Keele gardens, near Newcastle, the seat of the Rev. Walter Sneyd, there is growing a holly

hedge 110 years old, 100 yards in length, 6 feet wide at the top, 20 feet wide at the bottom, and 32 or 35 feet high. Speaking of the old trees of North Wales, I must mention that there is a splendid avenue at Wynastery, near Wrexham, upwards of a mile in length, formed of fine oaks, elms, limes, and beeches: one ash, called the "King," measures 36 feet in circumference. There are likewise many fine oaks mentioned in the "Natural History of Staffordshire," page 408, which are worthy of investigation.

It will be with great pleasure I shall look forward to further information upon the subject of old trees in the pages of your magazine.

NOT

THE DARTER.

E. EDWARDS.

(Boleosoma Olmstedi, Storer.)

BY CHARLES C. ABBOTT, M.D.

OT all of our little fishes are "minnows," although a very common want of knowledge of fish generally results in persistently calling everything not a shad or sturgeon, a "little minnie." Now, these ignorant people notwithstanding, there are pretty little fish in all of our streams that bear as little relationship to small cyprinoids or minnows, as do these to the bulky sturgeons that visit our large rivers. Among all these little fishes there are none that are more interesting to the field naturalist than the pretty Darters, or Etheostomoids, as we prefer to call them.

In the upper waters of the Delaware river (U.S.A.), where jagged outcroppings of triassic sandstone and smooth glacial boulders dropped here and there in the bed of the stream, make little eddies in the current, and short stretches of smooth sand bottom, just below the bases of such projecting rocks, there are to be found, from June to November, dozens of bright yellow and deep black fishes, narrow-bodied, extravagantly supplied with fins, that vary in length from one inch to five; and it will be noticed, if you approach quietly, that they are always resting upon the sand, or some flat pebble, or smooth projecting ledge of the rock about which they linger. If you disturb them, away they go, with a most laborious movement of all their fins, that send the fish but a yard or two, at most, onward and upward, when they again sink to the bottom; unless a second effort is made to give them an additional "send." Take it altogether, it is the poorest apology for locomotion that we have ever seen in either fur, feather, or fin. Why, actually, if you find them in shallow water, which is frequently the case, you need but follow them up for a

little way, and you can run them down. A dozen yards, without rest, tires them out, and they can be caught with the hand.

The most abundant of the several species of this family found in New Jersey is the one we have here figured, the Tessellated darter, Boleosoma Olmsteai (B. tessellatum, in vol. i. of "Gunther's Catalogue of Acanthopterygian Fishes," p. 77). Although, like all the family, it is a poor swimmer, it cannot be called a sluggish or inactive fish. Its prominent eyes readily spy out wee crawling creatures, that soon escape the notice of the ichthyologist, as he watches the fish before him; and when such minute forms as Etheostomoids largely feed on, do come creeping near, the little "darter" puts his every fin in rapid motion, and pounces down on the unsuspecting object, which it appears never to fail in seizing; and then, with every fin wide-spread, the fish sails off, with stately mien, that is somewhat ludicrous, and settles down quietly, in the spot from which it started, to leisurely devour the morsel it has secured.

Unlike many of the Etheostomoids, the males of this species are not arrayed in gorgeous colours in the spring, but are merely brighter in their tints,

Fig. 49. The Darter (Boleosoma Olmstedi).

our own experience goes, this species will not live in an aquarium, because the water is not in motion, and thereby well aërated; but there are Etheostomoids that are not so sensitive in this respect.

In SCIENCE-GOSSIP, No. 86, we briefly hinted at catching "darters" with a hook and line. This is not a difficult matter, but is rather a slow way of collecting them, if that be the object of capturing them. Like all percoids, darters are certainly very voracious, and will bite at anything, even though unable to seize it fairly, letting alone the possibility of swallowing it. So, if a very small hook is properly baited, it will be readily seized, if dropped immediately in front of and near them. This disposition to snap at everything that presents itself, places these little fish among the scavengers of our streams; for we have noticed that a decomposing fish or other animal, when caught by a projecting rock or stick, will be frequently surrounded by great numbers of these darters, and the carcase will be continually pounced upon and bitten at, until the bones are pretty well picked.

Of the several other species of this family of little fishes, we will not say anything now; but if, in any of our rambles during the pleasant autumn months to come, we succeed in learning something new concerning the tessellated fellow, or in noting peculiarities in allied species, we will again jot down what we have seen, and, perhaps, make a drawing of another "darter."

Trenton, New Jersey, U.S.A.

A CHAPTER ON ANTS.

IT T is two years since I reported the progress of my formicary, and I intend now to add a few acts which have come across my notice in addition to my observations of previous years. I mentioned in SCIENCE-GOSSIP for 1871, p. 248, the fact of such large numbers of my ants (Myrmica ruginodis) escaping suddenly in a body. I thought at the time that my formicary must be very nearly emptied, but in the spring of the following year, 1872, when they woke up from their torpidity, I was pleased to find the colony stronger and of greater numbers than I had expected. They never again attempted to escape in the same manner, but got to look upon their nest as their legitimate home, and would I think have been unwilling to leave it. I often let the trough remain some little time dry before I refilled it, for I found that the stragglers only ran about the stand on which the formicary was placed, but seldom strayed any further.

At one time the glass sides of my formicary got so obscured with moss and rubbish, that the view into the interior was nearly shut out, so I removed them with the purpose of cleaning them, leaving the block of earth standing sufficiently safe. On

replacing the glass, since many ants were running over the perpendicular mound of earth in some excitement, unavoidably two or three of them got pressed into the earth, in places where there were no burrows, and were fixed between the glass and the mould, quite unable to move at all. Not long afterwards I was astonished to see several ants with much eagerness running a burrow straight towards the very point where one of these ants was incarcerated. They worked very hard, and after a time they excavated until they reached the imprisoned ant, upon which they pulled away and loosened the soil around it, until they had made sufficient room for it to wriggle out. Having watched the completion of this wonderful sight, I looked to see what was the fate of the other imprisoned ants. I found that there were two other parties of ants eagerly digging out two more of their comrades. They accomplished their object in due time, in one case running their separate galleries from three directions, all meeting at the precise spot where their lost companion was. A fourth ant was lightly pressed against the glass close to the very bottom of the case, and in a very unfrequented part of the hive, at some distance from any burrow, where I expected that he must remain; but the next morning I found a fresh and narrow path leading straight to where he had been, and the ant gone. When the first one of these had been liberated, it naturally seemed weak and stiff after the compression it had been subjected to, and crawled away in a feeble manner; but it was presently met by a companion and then remained motionless, whilst the other began at the head, stroking it all over, round and round, and elaborately pursuing the same course with the thorax and abdomen, feeling down each leg. It looked exactly like a surgeon examining a patient to see the extent of the injuries, and no doubt its intention in doing it must have been something of the same nature. Soon afterwards another ant came up and went through a precisely similar process. Finally the injured ant slowly disappeared out of sight into the formicary, surrounded by several of its companions.

How these ants knew that any of their com rades were incarcerated at all, and how that even then they knew precisely in what direction they should burrow, is one of those mysteries which baffles all conjecture. It shows, however, that they must possess some sense developed to a pitch of great intensity, and though the theory that insects possess a subtle sense unknown to us seems scarcely warrantable, yet it is hard to see which of our five senses, however much developed, would in this case have helped to the discovery of the plight of their companions. If it is the sense of hearing which they have so acutely, it must be modified to their special requirements, for they appeared quite obli