Keep a receptacle to use as a receiving and curing tank, into which all fresh specimens are placed, with abundant room for each to undergo the curing process. Every animal contains in its body a heavy percentage of water, which must be, in great measure, replaced by the spirits before the flesh can be preserved from decay. Into the first bath a great quant.i.ty of blood and abdominal fluids will be soaked out from the specimen, and it is bound to lose strength rapidly, and also become foul. As long as it remains clean enough to use, keep up its strength by the addition of pure spirits, and in it immerse all specimens until they are thoroughly cured. Give them plenty of room at first, and keep them from settling down to the bottom by putting there a bunch of excelsior, tow, or cloth. While the spirits in a can may be strong enough on top to preserve a specimen, at the bottom, where the animal impurities settle, it may be so weak that anything lying in it would soon spoil. Often the tail of a fish which hangs upright in a jar will spoil while the remainder will be preserved.

After specimens have remained in the receiving-tank for from two to four days, according to size, put them in another receptacle in clean, fresh spirits, still allowing them plenty of room. Finally, when ready to pack up and make a shipment home, wrap each fish separately in a piece of thin, white cotton cloth, just large enough to cover it well, dip it in clean spirits, and without any tying or pinning of the cloths, lay the fishes in your barrel like sardines in a box, as closely as they will lie without being squeezed. Fill the receptacle full of fishes, head it up, and then pour into it all the clean spirits it will hold.

In order to proceed with the second and third methods of preserving fish specimens, it now becomes necessary to describe a process.

HOW TO SKIN A FISH.--Of course, no one aspiring to become a collector of fishes will remain in ignorance of the names of the different fins. And, more than that, before he can prepare even the rough skeleton of a fish he must know what its bony structure is like. On the whole, there is a good deal to be learned about methods in collecting fishes, and as a beginning we must learn how to skin a scale fish. The methods with cartilaginous fishes will be considered later.

The principles with all scale fishes are precisely the same, the only difference being in the greater amount of cold steel and energy required for such great, hulking brutes as the jewfish, and the magnificent tarpon.

For convenience we will take a specimen about a foot in length; for example, a striped ba.s.s, a pike, or a red snapper.

As is the case with quadrupeds, the left side of a mounted fish is always expected to be "the show side." Lay the specimen upon its left side, start at the vent with a stout pair of sharp-pointed scissors, and divide the skin in a perfectly straight line along the median line of the belly toward the head, stopping the cut when you approach close to the narrow, tongue-like point which terminates between the lower angles of the gill openings. Now reverse the fish, begin again at the vent, and divide the skin with a clean cut through the scales, in a line parallel with the base of the a.n.a.l fin, and about half an inch from where the scales meet the fin rays. This is really a cut along the side of the fish, as low down as possible, made necessary by reason of the a.n.a.l fin. Continue this cut straight back to the tail, as shown in the dotted line _g-h_ in Plate IV.

[Ill.u.s.tration: PLATE IV. HOW TO CUT OPEN AND MOUNT A FISH.]

You will find that the ventral fins are joined together in the flesh by a strong bony arch, called the pubis, and this must be divided through the middle so as to entirely separate the fins. The a.n.a.l fin-rays must now be cut loose from the interior rays (called interhaemal spines), which are really their bony foundation. The ventral fins must also be cut loose from the pubic bones at the point where they are articulated. Now take the cut edge of the fish skin between the left thumb and forefinger, and with the cartilage-knife carefully cut the skin free from the flesh. Be careful not to disturb the white layer of color pigment which is spread like a silver lining of feeble tin-foil over the inside of the skin. This is what gives the fish its silvery color, and if skinned off or sc.r.a.ped away the skin will look like colorless parchment. _Whatever you do, do not disturb that color lining._ Proceed with the skinning until the skin has been detached from the entire upper side of the fish. This brings you to where the dorsal and caudal fins are inserted.[6]

Now turn the fish over, and proceed as before, as far as you can go. You presently reach the caudal fin, which must be cut loose from the end of the vertebral column as far back in the skin as possible. When this has been done, the skin and the fleshy body still hang together by the attachment of the rays of the dorsal fin to the interhaemal spines. Cut these apart with the scissors, from back to front, close up to the skin, which brings you to where the vertebral column joins the skull. You will make very short work of that, which frees the fleshy body from the skull. Now sc.r.a.pe away the surplus flesh from the inside of the skin, wash it thoroughly, remove the gills (if they are not to be studied), and lay the skin flat upon its side in your tank of alcohol.

By thus preserving the skins of fishes, instead of whole specimens, a great number of really large specimens can be preserved in a small quant.i.ty of alcohol, for at the last they can be packed together, heads and tails, precisely like sardines.

SKINNING CARTILAGINOUS FISHES.--_Sharks, Rays, etc._--The skinning of a shark or saw-fish calls for no special instructions in addition to the foregoing, except that the long, narrow, pointed tail requires to be slit open along the right side of its upper lobe for a considerable distance.

Remember the principle that wherever there is flesh, a way must be made so that it can be removed, or at least reached from the inside by the preservative. Of the skull, nothing is to be left attached to the skin except the jaws. The skeleton is wholly of cartilage instead of bone, and is easily cut through.

The extremely flat, circular-bodied ray, also with a cartilaginous skeleton, must be opened on the underside by two cross cuts at right angles to each other, one extending from mouth to tail, and the other from side to side. The fin rays are very long stems of cartilage, set so closely together as to form a solid sheet of cartilage extending from the thoracic skeleton out to the extremities of the fins, which taper out to nothing.

The thoracic skeleton gives shape to the body of the ray, particularly the back, and it must be left in place, with the skin of the back attached to it. Cut through the fin rays where they join the body, and this will enable you to skin down each side of the fish until you get so near the outer edge there is no longer any flesh. Stop at that point, cut the flesh away from the fin rays, and cut away as much of the fin rays themselves as you please.

Clear out all the flesh and preserve the skin in a very strong solution of salt and water (what is known to chemists as a "saturated solution"), or in alcohol if you have it to spare.

PREPARING ROUGH SKELETONS.--In about seven cases out of ten, it is a far easier and more simple matter to rough out, clean, and mount the complete skeleton of a fish than the uninitiated would naturally suppose. A few fishes, such as the shad, have more bones than the law allows, and the preparation of a complete skeleton thus becomes a practical impossibility.

Fortunately, however, most fishes are more reasonable in the matter of bones, and to these we direct our efforts.

First and foremost, study the bony structure of a typical scale fish, learn what its princ.i.p.al parts are, and how they are articulated. Learn how the ribs lie, and how a row of slender, riblike bones called appendices, or epipleural spines, are attached to the true ribs, and at their outer extremities _touch the inside of the skin_ along the lateral line of the fish. If you will take a good-sized perch as your first subject, you will not be troubled with any osteological extras, and the process will be as follows:

Lay the perch upon its side, and with a sharp scalpel cut away the skin from the whole of the exposed side. Remove all the viscera. By careful examination, ascertain the exact location of the ribs, and particularly the row of epipleural spines attached at the upper ends of the former. With a broad, flat bone-sc.r.a.per, or your knife-blade if you have nothing better, begin at the lateral line of the fish, and work toward the top of the back, taking the flesh away in chunks as you go. In a very short time the vertebrae and the interhaemal spines are exposed, and with a narrower bone-sc.r.a.per the flesh is easily removed from them.

Now turn the fish around, and with great care cut and sc.r.a.pe the flesh away from the ribs and the epipleural spines. Do not on any account detach the latter from the former, but at this stage leave them attached to each other by a thin strip of flesh for their better protection.

Do not separate the ventral fins by cutting through the pubic arch, but with your small, curve-ended bone-sc.r.a.per remove the flesh from the angular recesses of these bones, and leave the anterior end of the pubic arch attached to the coracoid. Next, pick out the flesh from around the base of the pectoral fin, remove the eye from its socket, and whatever flesh the skull contains. Thus does the bony structure of one entire side stand revealed. The gills are of course to remain in place, as the skeleton would not be complete without them.

There is but one thing more to add. In treating the other side of the fish in a precisely similar manner, care must be taken to not disturb the attachment of the interneural and interhaemal spines which join the dorsal and a.n.a.l fin rays to the processes of the vertebral column.

Having thus denuded the fish of its flesh, lay the skeleton in a pan of water, and with a moderately soft tooth-brush, or nailbrush, brush it carefully to wash away all blood and mucus. If the bones are full of blood (which is very rarely the case), the skeleton must be soaked in clear water for an hour or two, or longer if necessary, to soak out the blood, so that it will not dry in the bones and permanently disfigure them.

Rough skeletons of fishes may be preserved in alcohol, but for many reasons it is much the best to dry them. Poison them with dry a.r.s.enic; _do not put upon them either salt, a.r.s.enical soap, or alum_, hang each one up by the head, and see that it dries in good shape. The pectoral fins should lie well down upon the ribs for mutual protection.

FOOTNOTE:

[6] Some operators open a fish in a straight line along the _middle_ of one side, but I have never been able to see any reason for this preference.

CHAPTER X.

COLLECTING MARINE INVERTEBRATES.

SPONGES.--A live sponge is simply a vast colony of protozoan animals, each member of which lives an independent existence, but all are at the same time mutually dependent upon each other. The sponge of commerce, and the "cleaned" sponge of the museum collection is, like a branch of coral, merely the skeleton of the living aggregation. A live sponge is a dark colored, heavy, tough gelatinous ma.s.s, cold and clammy to handle, quickly offensive if left in the open air, and utterly useless until "cleaned," or rid of its ma.s.s of animal matter. The skeleton of a sponge may be _h.o.r.n.y_, like that of the useful sponges of commerce; _silicious_, like the marvellously beautiful framework of the famous gla.s.s sponge of the Philippine Islands (_Euplectella_); or _calcareous_, like the curious little _Grantia_, which looks like a miniature bouquet-holder, with a frill of spines around its open end.

Owing to the extreme scarcity of sponge collections, very few persons know how great a variety of forms, and what really remarkable forms, exist no farther from home than the waters that wash the coast of our own beloved Florida. I once had the pleasure of collecting no fewer than sixteen distinct species on the beach between Biscayne Bay and New River Inlet, some of them of remarkable form, and all of them nicely cleaned for me by old Ocean.

Of course, I _searched_ for sponges, and found many a fine specimen buried almost out of sight in the sand,--but what glorious fun it was, to be sure!

There I obtained the large, coa.r.s.e "basket sponge" (_Hirvina campana_), a hollow, inverted cone, often capable of holding a pailful of water; the remarkable finger sponge (_Tuba v.a.g.i.n.alis_), which forms cl.u.s.ters of upright, hollow cylinders; a large cylindrical sponge of a rich brown color, and beautiful wiry texture, called _Verongia fistularis_; and sponges that were like trees, like interlocked deer antlers, and what not.

Professor H.A. Ward's last catalogue of invertebrates enumerated forty-three species of sponges that were on hand when the list went to press. Of these, the largest specimen was a huge Neptune's cup (_Paterion neptuni_), four feet in height, and shaped like a gigantic goblet, which came from the neighborhood of Singapore.

Therefore, I say, when on the seash.o.r.e, be on the lookout for sponges. If you can find them on the beach ready cleaned and dried for you, so much the better; but if you get them alive, the soft animal matter must be macerated and washed away, just as you would macerate the flesh from a large skeleton. Soak them in fresh water for a short time to macerate the soft matter, then wash it out in salt water, and keep this up until the sponge is at last clean.

CORALS.--The bleached white coral cl.u.s.ter of the cabinet is, like the sponge, only the skeleton of its former self. When it was forcibly torn from its foothold at the bottom of the sea it was covered with living coral polyps, which gave it the color which is peculiarly its own. Some species, notably _Madrepores_, when first taken from the water look like colored gla.s.s. The main branches are of a yellowish-brown tint, shading toward the tips to the most delicate and beautiful bluish purple. There is no way to preserve these colors, because they are due entirely to the presence of the living polyps. When those delicate organisms die, as die they must, the color vanishes, and if not cleaned and bleached, the coral a.s.sumes a dead, smoky brown appearance, suggestive of dust and dirt.

Therefore it is best to clean and bleach your corals at once. This requires a little time, but the process is "so simple a child can use it." Small specimens can be cleaned quickly by washing them in dilute muriatic acid, and afterward in clear water to keep the acid from going too far, and then placing them out in the sun to bleach. Large specimens cannot always be treated in this way, and the best plan for wholesale operations is to place the coral on the ground, in a sunny situation, and dash water upon it daily until the soft animal matter has been washed away, and the wind and sun combined have bleached the specimens to snowy whiteness.

As a general thing, the natives who live within reach of coral groves are in the habit of gathering it in quant.i.ty, cleaning it very successfully, and offering it for sale at prices that defy compet.i.tion on the part of any scientific collector whose time is worth more than fifty cents a day. The best thing the collector can do is to get acquainted with the native fishermen and boatmen, treat them well and pay fairly, and then, if there is anything in the sea that his collectorship wants, it will soon be forthcoming. Thus, instead of the growth of the collection depending upon one or two men, there will be from ten to twenty local experts directly interested in it. I once came to a complete deadlock with my interpreter and three boatmen on the translation of the word "coral." They were Singhalese and Tamils, and coral was worse than Sanskrit to them. Finally, as a last despairing effort, I took a pencil and began to make a sketch of a madrepore. The crowd watched its progress in breathless silence until very soon one appreciative auditor shouted triumphantly, _"Koki kalli!"_ The crowd joyfully echoed it, the mystery was solved, and in five minutes more we were afloat and on our way to seek

"The treasures of the sea, In the mystic groves of coral Where her spirit wanders free."

The packing and shipping of branching corals is a serious matter. I have tried every way I could think of, and have seen others do the same, and am firmly convinced that no matter how the large _branching_ cl.u.s.ters are packed, they are _bound to get somewhat broken anyway_! Of course, if you care to travel with them and see to their handling at every transfer, that is another thing, but who can do that? The trouble is that the individual branches are so very heavy for the diameter of the stems next the base, a sudden jar causes them to snap in two by their own weight. But then corals are very beautiful, very interesting, and no matter though they are troublesome, we must have them.

In packing brain coral, and other compact forms without branches, the princ.i.p.al thing is to wrap them in sufficient soft materials that their surfaces cannot get rubbed, for that would ruin them. Do not pack a large chunk of brain coral without putting a part.i.tion across the box to hold it firmly in its own place, no matter how the box is turned. In Ceylon I once took the trouble to divide a large box into twelve separate compartments for the reception of that number of coral specimens.

In packing branching coral, a good quant.i.ty of soft, elastic, fibrous material like coir, cotton, tow, oak.u.m, or something similar, is necessary.

From first to last, take whatever precautions are necessary to keep your corals from getting filled with dirt and litter. Each cl.u.s.ter must lie on a thick pad of your fibrous material. In order to get downward pressure upon it, to hold it in place without breaking the branches, take some soft paper or cotton cloth, roll up a long, cylindrical pad of cotton or something else, and thrust it far down into the largest opening between the branches, with one end projecting above the top of the cl.u.s.ter to receive and transmit pressure from above. This principle, if properly carried out, will enable the collector to so firmly fix even the most fragile cl.u.s.ter that it is fitted to withstand pretty rough treatment in transit without serious damage.

STAR-FISHES.--When star-fishes are first taken from the water their arms are pliant, but after a bath in alcohol they become perfectly rigid. If left to themselves when first put into spirits, the smaller and more spider-like species will almost tie their arms into double bow-knots, and insist on keeping them so forever after. Since the way to cure a star-fish is to soak it in alcohol for from six to twenty-four hours, according to size, and then dry it flat and in good shape, it becomes necessary to pin the small ones firmly in shape upon thin boards before immersing them, and then they will "stay put." See to it that while in the spirits all your star-fishes, large and small, cure in proper shape, flat, and with each arm flat and extended in the right direction. After removal from the spirits, pin out all those not already fastened upon boards, and then let them dry.

I have never found it necessary to poison the spirits, for the reason that dermestes and other insects seem to respect a dried star-fish for his own sake.

ECHINI.--In all tropic seas the collector is liable to find echinoderms, "sea-urchins," "sea-eggs," or "sea-porcupines." These creatures are usually spherical in shape, with the mouth underneath, and the internal structure of the animal is covered with a stout, calcareous sh.e.l.l of uniform thickness, which is set all over on the outside with a ma.s.s of protecting spines, usually fine and very sharp-pointed, but sometimes thick and blunt. In life the spines are movable, and by means of them the creature walks, or clings to its native rocks most tenaciously.

The best time to seek echini is at low tide, and the best places are those where the sh.o.r.e line is composed of rough rocks, scooped out here and there into shallow pools. Take with you a large basket, a large screw-driver, if you have one, or failing that, a knife with a long, stout blade. Wear old clothes, unless you can afford to spoil new ones. When the tide is low you can wade around in the now peaceful pools, and find the echini in the sheltered crevices, clinging to the bottom, or the perpendicular sides of the rocks, but always under water.

To dislodge them, the knife-point or the edge of the screw-driver must be neatly and skilfully worked under the victim far enough to enable you, with the exertion of some force and a steady pull, to pry him loose from the rock, whereupon he becomes your lawful prey. Next comes the cleaning process. With a small knife, detach the skin of the mouth parts from the edge of the round hole underneath, in the middle of which the mouth is situated, and remove all fluid and fleshy matter from the interior of the sh.e.l.l. That done, wash it out thoroughly. The bony jaws, or "Aristotle's lantern," may also be drawn out through the hole and thrown away--_unless_ you happen to be collecting for someone who is studying the anatomy of echini, in which case he must speak for himself.

Having cleaned your sea-urchin, put it in clean alcohol (same strength as for fishes) and let it soak for about twenty-four hours. This will prevent the spines from gently dropping off, like leaves in autumn, when you proceed to dry the specimen. After soaking in spirits, put the specimens out in a shady place to dry. It is a curious fact that all the echini of Ceylon and Malayana lose their spines unless soaked in spirits before drying, whereas those of the Red Sea, the Mediterranean, and the West Indies can be dried without soaking, and the spines will not fall off.

Sh.e.l.lS. _"Living" and "Dead" Specimens._--The first thing that the amateur needs to learn about a sh.e.l.l is that it may be living or dead. As a general thing, what is technically called a "dead" sh.e.l.l is worthless in a cabinet.

A live sh.e.l.l is one which has been collected with a living mollusc in it, and then duly cleaned, preserving all its beautiful colors. A dead sh.e.l.l is one in which the occupant died a natural death, has lain and bleached in the sunshine until its colors are entirely gone, and its form also ruined by the weather. Therefore I say, leave dead sh.e.l.ls alone, unless it be that you are making an exhaustive collection of the species in a given locality, when a dead sh.e.l.l which is identifiable is as good a record as a living one. Where a sh.e.l.l is actually devoid of color, a dead sh.e.l.l is as good as a living one, provided it is collected before its edges or its angles have been rounded by exposure to the sun and rain. Many a living sh.e.l.l has an epidermis, the same as an animal, while a dead sh.e.l.l has none.