CHAPTER VI.
SKINNING AND PRESERVING SKINS.
With a suitable specimen at hand it is for us to decide if we shall mount it or preserve it as a skin temporarily or indefinitely. To illustrate we will presume that we have a muskrat just from the trap which is to be mounted at once.
Before skinning it is best to get some measurements to guide us in the later work. In this case where the skin is to be mounted immediately a simple outline is sufficient, as we will have the body in the flesh and all the leg bones, etc., to guide us in rebuilding the creature.
To get such outline, lay the animal on its side on a piece of blank paper, put the feet and legs in some natural position, fasten them in place with a few pins and mark around the entire animal with a pencil. The eye, hip and shoulder joints, and base of skull may be indicated on this outline sheet. Our muskrat is a trapped and drowned one so we will not have to replace the shot hole plugs with fresh ones, as would be best if it had been killed with the gun. Also it has been dead long enough for the rigor mortis to prevent the free flow of blood and body juices which bother the operator if it has been killed but an hour or less.
Laying the animal on its back, make the opening cut by pushing the knife point through the skin at the juncture of neck and chest. Run the blade down between skin and flesh, separating the skin in a long clean cut to the root of the tail. Open the tail also along the under side from the tip to within an inch or so of its base. Slit open the sole of each foot from the middle toe to the heel and further if necessary so the leg skin may be turned down over the foot.
Beginning at this central cut, skin back each side until the shoulder and hip joints are encountered. Bending the limb will show the exact joint where the muscles are cut apart and the legs severed from the body. Cut off the tail near its base, leaving it in the skin for the present. Loosen the skin from back and shoulders and turn it wrong side out over the head. Skin down until the ears are reached, cutting them off close down to the head and continue on to the eyes. Work carefully around these and cut close to the skull to avoid hacking the eyelids. Cut through the nose cartilage, and when the lips are reached cut them away close to the gums, leaving both their inner and outer skin on the pelt. Cutting them off at the edge of the hair is a frequent cause of trouble as they are full and fleshy and should be split, pared down on the inside and when mounted, filled out to their natural shape to perfect the anatomy.
Now the skin of each leg may be turned wrong side out down to the toes and all flesh and muscle cut away from the leg bones with knife and scissors. The tail also is to be removed from its skin and the ears turned wrong side out to their tips. In skinning no flesh of any consequence should be left adhering to the skin and it should never be pulled off by main strength, but rather separated by the knife or fingers, pushing the flesh away from the skin rather than the reverse. The skull should now be cleaned as the leg bones were and if a number of specimens are being prepared at the same time the heads may be put in a kettle and boiled a short time, when on trying with a fork or awl the flesh becomes tender and may be rapidly removed with a knife.
The brain may be removed with a hooked wire, the skull well rinsed inside and out and given a good coat of arsenical paste or other preservative. The next step is determined by what you intend doing with the skin. If it is to be kept for purposes of study without mounting it should be made up as a scientific skin. If to be mounted at once or in the near future it should be put in the jar of salt and acid or alum. It can of course be mounted at once without this bath but I believe it is well worth any extra work it entails.
Some young furred animals and others with very delicate skins do not work up well from the bath and had best be mounted without it, being handled more as bird skins are.
In skinning the larger quadrupeds we make two additional cuts, from the right to the central line and out to the left fore foot and a similar cut connecting the hind feet. These opening cuts are on the back and inside of the legs, you will understand.
With most large subjects another cut from the shoulders up the back of the neck is necessary. On animals having horns or antlers this is terminated in a Y or T shape, reaching the base of the antlers. After loosening the skin around the antlers the head is removed through this incision. As it is hardly possible to make an outline sketch of a large animal, as full a set of measurements as possible is useful in all cases.
The bones of the legs will be in the way attached to the skin and the two upper bones of each leg may be detached and if lack of space or transportation make it necessary, thrown away, though if the bones of one hind leg and one front leg are preserved artificial duplicates may be carved.
In skinning birds, after fresh cotton plugs have been put in place the feathers are parted and the opening incision made through the skin only from the middle of the breast to the root of the tail. Separate the skin and flesh on each side until the knee is reached, push this up until the knife or scissors can be passed under it and the leg severed at the joint. A little corn meal sprinkled on the exposed flesh and the operator's fingers will prevent the feathers adhering and becoming soiled as the work proceeds.
Cut off the flesh in which the tail quills are rooted leaving it on the skin with one or two of the last vertebrae. Use care in this or you will cut the skin above the tail too. The body may now be hung up by a cord tied to the stump of one of the legs and both hands used in separating and turning the skin back until the wings are reached. The skin is loosened around these and they may be severed at the elbow joint unless the bird is to be mounted with wings spread, when it will be best to unjoint at the shoulder and preserve the entire wing bones.
With the wings detached we skin on to the base of the skull. In some of the ducks, and other water birds, woodpeckers and owls the neck is so slender and the skull so large that it is necessary to cut the neck off here and making a cut down the back of the head and neck continue the skinning of the head through it. Do not cut or tear the membrane of the ears but pull it out with the forceps and work down over the eyes, cutting the membrane connecting the skin but not the lids or eyeball itself. The liquid contents of the eye are particularly sticky and difficult to remove from feathers.
Continue skinning to the base of the bill, scoop the eyes from their sockets and cut loose the forward part of the skull from the neck. This is usually accomplished with four snips of the scissors much easier to practice than to describe.
Make one cut on each side of the head, through the small bone connecting the base of the lower jaw with the skull, another through the roof of the mouth at the base of the upper mandible and between the jaws of the lower, and the last through the skull behind the eyes and parallel with the roof of the mouth. This will free the skull of the neck and most of its flesh and muscle.
In most cases the head should be returned to the skin as soon as possible to avoid its drying out of shape and giving the feathers a wrong set. After cleaning and poisoning the skull and filling the eye sockets with cotton this reversing is undertaken. If working on a small bird the learner is apt to come to grief here, as only by careful and patient work without the application of some force is the returning process accomplished successfully.
The wings and legs may now be skinned down to the first joint and all flesh and muscle removed from the bones. This is done expeditiously by snipping off the end of the leg bone and stripping it down with adhering flesh to the ankle joint where it (the flesh) is cut off.
The wings are skinned to the first joint, stripping the wing primary feathers from their fastening on the bone with the thumb nail, clipping off the large bone near the end and detaching the small bone with all flesh and muscle adhering. If this is clipped off at the wrist joint the entire wing is cleaned. This method applies to all small and medium birds not wanted with spread wings.
In case wing spread is wanted the primary feathers are not disturbed but that part of the wing is cleaned from a slit in the under side of the wing. All but the smallest birds should have the tip joint of the wing slit open on the under side and some form of preservative worked in the opening. Specimens the size of a crow and larger should have a cut made in the bottom of the foot and the tendons of the lower leg drawn out with an awl, and in the case of very large birds it may be necessary to soak the unfeathered part of the legs and feet in a pan of strong pickle for 24 hours, to prevent decay and damage from insects. Our bird is now entirely ready for the application of such preservatives as we may be using.
The main principle in the preserving of skins may be stated thus: All skins must be removed and cleaned of flesh so the preservative may be applied to every part of the inner surface, where it will act directly on the roots of the hair or feathers.
The preservative applied, we must decide on the next step, whether it is to be mounted at once, in a short time, or laid away indefinitely as a scientific skin.
If we have to lay it away until tomorrow, put a little cotton inside to prevent the inner surface sticking together, wrap in a damp cloth and unless the weather is very hot it will be all right.
If very hot or it is necessary to lay it aside for some days, the inner side should be well coated with the carbolic and glycerine mixture. As a scientific skin it should be made up at once, tagged with a full set of measurements taken before skinning and laid aside to dry. These measurements are not needed if we mount it at once, as the skinned body is at hand for comparison, but the sex, date, locality and collector's name should be attached to the completed specimen.
Alligators and the lizard family are skinned like the other four-footed species, as are snakes and fish, with the exception they have no limb bones to be cleaned and preserved. Fish are better opened along one side than the central line of the body.
Reptile skins if not put in the pickle jar had better be packed in salt after poisoning as when entirely dry they are practically ruined. Skins of fish are best kept in either a saturated solution of salt (water with salt added until no more will dissolve), alcohol or formaldehyde solution. Whatever method is used the delicate colors will vanish and unless you can have a fresh specimen at hand when mounting it you should make the best color record you are able. This is true to some extent at least of all coverings of fur, feathers, or scales, and the stronger the light the more damage. I have seen a mounted mink placed in direct sunshine, bleached to a drab and the yellow feathers on a 'flicker faded almost white.
In order to preserve turtles, after killing with chloroform preferably, it is necessary in the case of the box or land turtles to cut a square opening in the under shell through which the body may be removed and the legs and neck skinned.
The water species can have the lower shell detached from the upper at the side and after cutting the skin around the rear two-thirds this shell is turned over to the front and the skinning and cleaning proceeded with.
If not mounted at once make into a dry skin after poisoning or small turtles may be put in alcohol.