5. Next attack the abdomen. Beginning at the lower point of the breastbone, detach the walls of the abdomen from the ends of the short ribs, down to the lumbar vertebrae, and so on around the iliac margin of the pelvis. Cut through the diaphragm close up to where it is attached to the ribs, and remove at one effort the entrails and vital organs.

6. Cut away the flesh from the pelvis, both inside and out, and the flesh of the tenderloin from underneath the lumbar vertebrae.

7. Cut the flesh from the thick portion of the tail.

8. Cut off the head at the first cervical vertebra, and clean the skull as previously described elsewhere, but leave _the hyoid bone in its place_.

9. Cut the flesh away from the neck vertebrae as well as you can. Be careful not to cut the sternum (or breastbone), which is soft cartilage, and easily cut; nor the ends of any vertebral processes, nor any soft bones.

10. If the skeleton is a small one, it is apt to get quite b.l.o.o.d.y during the operation. Wash it clean, and if necessary soak it in clear water for an hour or two. It will come all the whiter for it in the end. Skeletons of ruminant animals are generally clean enough without that.

11. Do not poison a rough skeleton with a.r.s.enical soap, nor put salt upon it; so says Mr. Lucas, the osteologist of the National Museum. The former has a tendency to prevent skeletons from properly macerating and coming white. Sprinkle dry a.r.s.enic upon a skeleton, if anything is necessary to protect it from _Dermestes_ and other insects. Never put alum on a skeleton.

[Ill.u.s.tration: FIG. 66.--Rough Skeleton of a Small Animal. (After F.A.

Lucas.)]

12. The last thing is to make up the skeleton into a small, compact bundle, that will pack nicely and economically when dry, and withstand some pressure without breakage. Put the skull in the chest cavity. Fold up the upper joints of the legs, put the foot of each in the pelvis, and the other end in the cavity of the chest. Now tie all the legs tightly to the spinal column. (See Fig. 66.) Bend the tail under the pelvis and tie it fast also.

Finally, hang the specimen up in the shade and wind, so that it will dry quickly.

It will be observed that the above process leaves the body of the skeleton entire, and all the bones of each leg and foot united by their natural ligaments. A skeleton prepared thus may ultimately be mounted as a "ligamentary skeleton," or it may be disjointed throughout, macerated, and mounted as a "disarticulate skeleton." Except for skeletons of bison, elk, and other animals which are entirely too large to admit of transporting their bodies whole, it is much the best to prepare all others in the field as described above, and disarticulate some of them afterward; for this reduces to a minimum the chance of losing some of the parts.

SKELETONS OF LARGE MAMMALS.--The process of roughing out the skeletons of large mammals, no matter how large they may be, is precisely the same as described above for small ones; but to make it possible to transport and box them, they must be cut to pieces, or, I had better say, _disjointed_, for fear some zealous partisan might interpret my words too literally, and go at a valuable skeleton with an axe. And right here let me publish a law which is as fixed and unalterable as the laws of the Medes and Persians, and admits of no exception:

_In disarticulating a large skeleton, no matter how large, an axe or hatchet must never be used for any purpose whatever._ Use nothing but the knife, and in a few cases a small saw to separate the sternum from the ends of the ribs.

To come down to the details of cutting up a large skeleton in, the field, and making it up into a number of separate bundles, let us suppose that the skeleton lies before us, completely roughed out, in accordance with previous advice. The bones of each leg must be dislocated (at the "knees"

in ruminant animals) either once or twice, so that the parts can be easily handled. In a full-grown elephant the leg bones are so large it is necessary to cut the ligaments at each joint, so that the scapula, humerus, radius and ulna, and foot may each be handled separately.

Of course, the head is to be cut off at the first cervical vertebra. Then, by careful work, and much coaxing with the sharp point of the knife, dislocate the spinal column just where the neck joins the body. At first this will bother you, but have patience and you will soon learn how to do it easily and quickly. In dislocating the spinal column, take hold of the neck, move it backward and forward, and strain it a bit to see just where the articulating surfaces of the vertebral process are, so that you can cut them. When your intelligence has made some headway on the joint, then you may put forth a little main strength and tear the vertebrae apart, but do not attempt this too soon.

The next thing is to cut off the ribs, and the first step toward this is to cut out the sternum, or breastbone. (See Plate XX.) This so-called bone is really cartilage, soft enough in a fresh skeleton to cut on the outside, and in thin places, like cheese rind. It must be cut out in one piece, the same as may be seen in the figure of the mounted skeleton, and the dotted line _A B_ shows where the cartilaginous ribs of the sternum join the bony ribs that form the main arch of the thorax. At the points marked by the dotted line, cut the two apart. I have never found it necessary to use a saw for this work in a perfectly fresh skeleton, but in dry ones a saw is necessary. When you come to the short, or "floating ribs," as they are called, it will be found that their cartilages are only attached weakly to the cartilages of the previous ribs, or else are altogether free. These must be cut from the ribs and preserved with great care.

After the ribs have been cut free from the sternum, separate them from the backbone, one by one, make them up into bundles, and tie them up. The pelvis is to be separated from the spinal column at the last lumbar vertebra; and if necessary the spinal column may be again dislocated about the middle.

Formerly it was my practice to poison all rough skeletons with a thin wash of a.r.s.enical soap, to make them dry without smelling badly, and to keep off the myriads of insects that the shreds of flesh would naturally attract.

Now, however, in obedience to the mandates of Mr. Lucas, I have eschewed the use of a.r.s.enical soap for this purpose, and recommend the use of dry a.r.s.enic instead, which does not r.e.t.a.r.d the cleaning of the bones.

ROUGH SKELETONS OF BIRDS.--As in the case of a small mammal, first remove the skin from the body; but if the ident.i.ty of the bird is in doubt, leave the large tail feathers and the primaries in place, for future reference.

In fact, it is a good plan to always leave the primaries and spurious quills on the wing, for then there will be no danger that some of the small bones of the last joint will get lost or cut away by mistake. Moreover, when you come to tie up the skeleton, the primaries will afford valuable protection to the ribs.

[Ill.u.s.tration: FIG. 67.--Rough Skeleton of a Bird. (After F.A. Lucas.)]

With a bird, the entire skeleton should be roughed out before any disjointing is done, and even then none is necessary, save to cut off the legs of large birds, especially those with long legs. Study carefully the accompanying figure of a bird skeleton (Fig. 67), and then it will be hardly necessary to say more than to roughly, but carefully, cut off the flesh with a cartilage knife or scalpel, and remove all the viscera. Look out for those delicate little points on the neck vertebrae, and also be very careful not to cut off those curious little appendages (called uncinate processes) that project backward from the middle of each rib. Leave the hyoid bone in its place, and also the bony ring surrounding the eyeball of the great blue heron, the owl, and other birds of prey. If any portion of the windpipe reveals any bony structure, the entire windpipe should be saved. Whenever any tendons are found to be partly ossified, as they will certainly prove to be in the "drumstick" of your Thanksgiving turkey, leave them in place for the osteologist to do with as he pleases.

_When in doubt about any special part, give the osteologist the benefit of the doubt by saving the special part for him._

If the bird is a large one, cut off the head, and after cleaning it pack it away in the chest cavity. If the bird is small, you can leave it attached to the neck, and remove the brain by bending the head down and cutting it half off from above, thus exposing the occipital opening at the back of the skull, through which the brain may be drawn out.

After the skeleton has been roughed out, it should always be cleaned by washing it in a basin of water and brushing it meanwhile with a soft tooth-brush. If blood is left on the skeleton, the bones will absorb it, and become permanently discolored thereby. The cleansing done, make the skeleton up into a compact bundle by folding the wings naturally against the body, bending the neck down in some way so that it can be tied upon the body, and either cutting off the legs and putting them into the thorax and pelvis, or leaving them on and folding them up as compactly as possible.

Then tie the bundle up thoroughly by pa.s.sing a light string many times around it, so that it can never lose its compactness. Sprinkle it with dry a.r.s.enic, or wash over with _thin_ a.r.s.enical soap, and hang it up in the shade to dry.

SKELETONS OF REPTILES.--After all the foregoing directions, it surely is unnecessary to describe, in detail, the skeletonizing of reptiles. The principles are precisely the same as already set forth for birds and mammals. Wherever special bones or cartilages are found, as in the abdominal-cartilaginous ribs of crocodilians and certain lizards, they must be carefully saved whole and _in situ_. With large skeletons, take whatever means are necessary to get them, while fresh, into compact shape for drying and packing. With large crocodiles and alligators, the neck, legs, head, and tail all go nicely inside the body, as I have proved scores of times.

The skeleton of a large serpent is easily done up in a close coil, by which it not only takes compact shape, but the ribs are well protected. With serpents, do not attempt to cut the flesh from between the ribs, for it is desirable that it should remain.

On each rib of a crocodilian there is a strange, flat piece of cartilage attached to the posterior edge at the middle of the rib, and projecting backward, quite overlapping the next rib, as sure as the world the reptilian development of what in the full-fledged bird becomes a bony uncinate process. You will soon discover this in skeletonizing your first crocodilian, and be sure to respect its anatomy.

It surely is superfluous to say that every skeleton must be carefully and fully labeled, and in a substantial way.

FISHES.--This subject has been treated in Chapter IX. (Collecting Fishes).

_Skeletonizing Cetaceans._--The rough skeleton of a cetacean--porpoise, blackfish, whale, and the like--is the bloodiest, greasiest, nastiest specimen the collector ever has to prepare. Nevertheless, they are necessary evils, and fortunately their structure is so simple that their roughing out is not a difficult matter. The vertebral column terminates in a point, there being no bones in the flukes of the tail, or the dorsal fin.

The best way to operate is to split the body open along the middle of the back all the way from head to tail, and carve the flesh away until you reach the vertebral column, and after that the ribs.

The vertebral column must be cut in two in two or more places, according to its size. Midway between the last pair of ribs and the tail, and underneath the vertebral column, lie two very useless and absurd little ossifications known as the pelvic bones. They are called pelvic bones because that happens to be a handy name. They bear about as much resemblance to a genuine pelvis as a cigarette does to a locomotive. They are so small that it takes an expert with a search-warrant to find them, and, for my part, I always consider their loss a real gain to the cause of science. Of course the scapula and flipper, the ribs and the sternum, must each in turn be cut away, cleaned as well as possible, and bundled up to go with the head and the three sections of the vertebral column.

PACKING SKELETONS.--All rough skeletons, skulls, etc. (as well as all skins) must be thoroughly dry when packed, or they will sweat, soften up, smell offensively, and spoil any dry skins, or other perishable objects that may be packed with them. Skeletons should always be packed in tight boxes, so that rats and mice cannot get into them and gnaw the small bones.

Tie some soft material over the teeth of separate skulls to save them from getting broken. Put the largest skeletons and skulls at the bottom, and use hay, straw, or excelsior for filling. Of course the small and fragile specimens will be put in the protected corners and crevices between the larger objects, and, as before remarked, dry skeletons that have been made up into compact bundles will stand a very considerable amount of pressure without breaking.

COLLECTING FOSSIL SKELETONS.--The vertebrate zoologist glories in the skeleton of almost any living species of vertebrate, but a fossil skeleton he fairly worships. The more of previous theories it upsets, the dearer it is. If it is a reptile with feathers on its tail, a bird with teeth, or a scientific what-is-it, as was the gigantic megatherium, it is simply canonized. Beware, then, red-handed hunter of living species, how you recklessly pa.s.s by a bit of bone protruding from a "cut bank" beside some stream, for you know not the day and the hour when you may touch elbows with His Mysterious Highness, the Missing Link.

The tertiary deposits of the United States contain the fossil remains of many magnificent vertebrates, impossible even to mention here. Very often huge bones and tusks of the mastodon are unearthed in well or ditch digging, and before they receive proper attention are exposed to the air and allowed to crumble into dust in a few hours. If a fossil bone is very soft when dug up, it will crumble in a short time unless properly cared for. If this is likely to be its fate, cover it up again without delay, to keep the air from it until you are ready to preserve it. To accomplish this, prepare a kettle of glue water (simply hot water with a little glue dissolved in it) and wrap the bone tightly from end to end with an abundance of twine. Then with a ladle or large spoon pour the glue water over the bone or tusk, gradually, but continuously, so that it will soak in, and when dry, it will bind together the weak material and form a hard sh.e.l.l of some thickness and protect the form of the bone intact. This will often save a fossil which would otherwise fall into countless tiny fragments in a few hours.

If a skeleton or portion thereof is embedded in a matrix of hard rock, do not attempt to work it out fully in the field. That is work for the laboratory--and a very good one at that, sometimes requiring costly tools, much skill, and plenty of time to chip away the surrounding rock.

Oftentimes the fossil remains of a fish, small reptile, or mammal are uncovered bodily by the removal of the slab of rock which has covered it for ages, like a blanket. In such cases do not attempt to pick the bones, one by one, out of their resting-place, but procure the necessary tools, cut out the entire slab of rock which contains the skeleton, and keep it in one piece forever. Such specimens have a good market value in cash, which will well repay the care and labor bestowed upon them; but at the same time a novice should not make the very common mistake of supposing that a fossil which is new _to him_ must necessarily be worth its weight in gold. If you wish to sell any good fossils, you will get a fair valuation by offering them to Professor Henry A. Ward, Rochester, N.Y.

CHAPTER x.x.xVII.

CLEANING LARGE SKELETONS BY MACERATING.

There are two ways to clean the skeletons of large mammals: (1) by boiling the bones, and (2) by maceration. The first is short, cleanly, and agreeable; but the skeleton produced by it is sure to be full of grease, and is anything but white and pleasing to look upon when mounted. The boiling process is also detrimental to the texture of the bone. The professional osteologist, to whom a greasy bone in a mounted skeleton is an unpardonable offence, never thinks of boiling a skeleton to get the flesh off, for the reason that the grease is boiled _into_ the bone instead of out of it. Cleaning by boiling is permissible only under exceptional circ.u.mstances. If you wish a particular skeleton for a special purpose within a very short time, or if you are so situated that macerating a skeleton is impossible then boiling is excusable, but _steaming_ is far preferable.

PREPARING A SKELETON FOR MACERATION.--It is, of course, to be understood that it is only the skeletons that are too large to be sc.r.a.ped and mounted as "ligamentous skeletons" that are to be macerated, bleached, and afterward articulated with wire. The first thing to do is to cut out the sternum in one piece, as already shown in Plate XXI., poison it in a.r.s.enic water, and hang it away to dry and be sc.r.a.ped afterward. A sternum must never be macerated, for it is so soft the cartilaginous framework would be entirely destroyed. The skeleton must now be cut completely to pieces, excepting that it is not necessary to separate all the vertebrae of the spinal column. The ribs must be cut off, and the joints of the legs cut asunder. The large bones of the legs contain marrow, and of these bones each one must have a large hole drilled in each end on the face of the articulating surface, so that when mounted the holes will not show. These holes are to afford the water access to the interior of the bone.

MACERATING AND CLEANING.--The maceration of a skeleton is a question of time as compared with eternity. Procure a wooden barrel or keg large enough to contain the entire skeleton, knock the head out and see that there are no nails, nor any other metal anywhere on the inside to stain and discolor the bones. Pack the skeleton closely in the empty barrel, fill it up with water and let it stand. In a few days its offence, like Oth.e.l.lo's, "is rank, and smells to heaven." But that is no matter, provided your barrel has no neighbors. Let it stand for four months, six months, a year, or two years if need be, until every particle of fleshy matter on the bones has disintegrated and become a pulp. Keep the barrel covered, and when the water evaporates and the bones on top are about to be exposed, fill up with water and keep the bones always covered. If a skeleton is very b.l.o.o.d.y, it is well to soak it for a week in salt water to dissolve the blood-corpuscles. Then it may be macerated as directed above. The odor will be horrible, but if you are going to study bones you must not mind that.

When you find upon examining the bones that the flesh has totally disappeared from them, leaving them dark-colored or even black, but without any fleshy matter upon them, they are then to be taken out. Pour off the water, place the entire contents of the barrel in a large sieve-bottomed tray, and wash the bones thoroughly. When that has been done, put them in a large tub of boiling water, and keep them in warm water while you sc.r.a.pe all the bones, one by one, with your bone-sc.r.a.per, and scrub them with a stiff brush, going over the entire surface, and washing them meanwhile in the warm water. The interior of each of the large leg bones must be washed out with a strong syringe, and every cavity in the vertebrae must be carefully sc.r.a.ped out.

BLEACHING.--Having carefully sc.r.a.ped and washed the bones, the entire skeleton is now to be soaked for a short time, the length of time varying according to the size and age of the skeleton, in a solution of chloride of lime and water. To make this of the proper strength, dissolve about two or three ounces of chloride of lime in a barrel of water. Bones of young or immature animals must not be left in this solution as long as those of old specimens. Young bones are soft and porous, and the chloride of lime will soon destroy them if they remain in it too long.

The following skeletons, adult in every case, require to be left in this solution a length of time as stated herewith: Dog, 6 hours; sheep, 6 hours; deer, 8; buffalo, 12; elephant, 12.

After removing the bones from this bath, wash them with clear water, lay them in slat-bottomed trays, with cheese-cloth above the slats, without piling one bone upon another, and expose them a number of days in the hot sun. After they have bleached on the upper side, turn them over. If it does not rain upon them occasionally, they should be sprinkled with water, late in the evening or early in the morning, to hasten the process.