In cleaning bird skeletons beware of injuring the little tack like points which project downward from each of the cervical vertebræ. Have a care also for the soft bones of the coccyx, and the uncinate process which projects backward from the posterior edge of each rib. In fishes the greatest difficulty lies in leaving the ribs attached to the remainder of the skeleton, for if the operator is at all as the writer used to be in the days of his youth, he will be prone to scrape some of the ribs loose, and be obliged to glue them in place in the dry skeleton, with glue and cotton batting that has been clipped up finely with a sharp pair of scissors.
While a small skeleton is undergoing the scraping process it must not be allowed to get dry until it is finally set up in position. When the skeleton is not being worked upon, it must be kept soaking in clean water; but remember that this cannot go on very long, or maceration will set in, the ligaments will give way, and the bones will all come apart. A little borax in the water serves to arrest decomposition, and will allow a skeleton to remain soaking for several days longer than could otherwise be allowed. After a skeleton has been well scraped, in order to get it as white as possible and free from grease, it must be treated with
Javelle Water.
1/2 pound chloride of lime.
1 pound common washing soda.
1 gallon of boiling water.
Keep this on hand in a glass-stoppered jar, in the dark. In using it, draw off a small quantity in a broad, shallow, earthen dish. Lay every small skeleton in it, and with a soft tooth-brush of the right size, brush all the bones thoroughly for about five minutes. At the end of that process wash the skeleton thoroughly with clear water, and perhaps it is then ready to mount.
Often the bones of a small skeleton contain an inordinate amount of grease. The easiest and simplest way to remove it is to soak the greasy bones for several days or weeks, as may be necessary, in a jar of pure naphtha.
Mounting a Small Skeleton.—The skeleton of every bird, mammal, and reptile requires to have the spinal cord replaced by a stout zinc wire, to give both strength and rigidity to the structure. Zinc wire is necessary because iron wire will rust, and brass wire is too expensive to use when something cheaper and better is obtainable. If you cannot procure zinc wire, use good galvanized iron wire. For very large specimens you may use iron wire, but it must be covered with two coats of asphaltum, applied with a brush, like black paint. After inserting the wire the full length of the cavity of the spinal cord, leave enough of the end protruding beyond the first vertebra of the neck to afford a means for the attachment of the skull. The extra length to be allowed should always be nearly equal to the lateral depth of the brain cavity.
Attitude.—It is often somewhat difficult to decide upon the attitude the skeleton is to have when finished. The possibilities in this line are extensive, and the result depends entirely upon the character of the subject, and the knowledge and good taste of the operator. In the first place, the position of the skeleton must be a correct representation of some characteristic attitude of the species. For example, a sloth skeleton should hang underneath a branch; a monkey should be climbing, or walking on a stout bough; a hyena should sneak and crouch; a passerine bird should always perch, while the penguins and the auks must stand erect on flat pedestals. If the young osteologist can do so, it will pay him well to travel several hundred miles, if need be, to see the beautiful, and even elegant, collection of skeletons and other preparations in Mr. F.A. Lucas's Department of Comparative Anatomy in the National Museum, all of the specimens in which have been prepared, mounted and displayed by Mr. Lucas and his assistant, Mr. Joseph W. Schollick. I know of no other osteological collection which in the beauty and scientific accuracy of mounting, and exhibition arrangement of its specimens, can be considered equal to this. The museum-builder may well consider it a model of its kind. Every skeleton, from that of a tiny humming-bird to a whale forty-eight feet long, is as nearly perfect as human skill can make it, and the variety of the characteristic attitudes represented in the smaller species makes this collection a particularly attractive one.
PLATE XX.
[a]Ligamentary Skeleton (Domestic Cat).—Mounted and Drying.]