[Illustration: FIG. 68.--Steel Bone-scrapers.]
SCRAPING A LIGAMENTARY SKELETON.--The removal of the flesh and other animal matter from a small skeleton is accomplished by scraping the bones with various chisel-edged scrapers specially designed for this work, and by clipping and trimming on the joints with either curve-pointed or straight scissors. The principles to be learned in skeleton-scraping are comparatively few and simple. In the first place, a sufficient quantity of the connecting ligament at each joint must be left to hold the two bones together in proper shape when the specimen dries. This must not be left in a thick, unsightly mass, but requires to be scraped and trimmed down so that it is reduced to as small a quantity as will serve the purpose. In scraping the flesh off the main stem of a bone, such as the humerus, for example, always begin at the end and scrape toward the middle. The skeletons of turtles, lizards, and the like are an exception to this rule by reason of their structure, and should be scraped from the middle toward each end. If you scrape from the middle of a mammalian or avian bone toward either end, before you are aware of it, you have loosened the attachment of the ligament, and have nothing left to hold the joint together. By beginning on the ligament itself, and working away from it, you can scrape it down so thin at the point of attachment that its identity is quite lost, and the point where it ends is hardly visible. This principle applies to the scraping of all ligamentary skeletons, except a few reptiles.
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.