Rensselaer Union, Volume 7, Number 52, Rensselaer, Jasper County, 16 September 1875 — Bones. [ARTICLE]

Bones.

When a new bone finds its way into the student’s hands he observes, says Prof. Elwin, some peculiarity in shape or structure in which it differs from the bones he is already acquainted with; the question naturally occurs to him: Why does this bone assume one shape in one animal and in another is modified into a different form? He may look in vain in his books for an answer to his query. And yet it is points like these which, in my opinion, make up the true science of osteology. It is through careful, constant apd intelligent observation that these enigmas aretb be solved. Observation, indoors and out; close attention to the habits of the animal in question on the one hand, and careful consideration of its anatomical peculiarities on the other. Take the skull of a crocodile. What do we find ? The drbits of the eyes, the nasal orifice, the passages leading to the auditory apparatus, all situated on a plane along the upper flattened surface of the head. What, then, is the cause of this ? Palpably, to allow the crocodile to remain submerged in the water, with its nose, eyes and ears just above the surface to warn him of the approach of enemies or prey, and the rest of his carcass securely hidden beneath the waters. Take another instance. Observe the habits of a mole. With what rapidity it burrows under ground, shoveling away the earth with its fore feet. Then look at its skeleton. We find just what we should have expected. The bones of its fore legs of astounding strength and breadth, furnished with deep grooves, which, together with its sternum or breast bone, which is furnished with a keel almost like that of the sternum of a bird, afford attachment to the powerful muscles. Its hind legs, being simply needed for locomotion, are of the normal size. So also with the birds. The size of the keel of the sternum varies in proportion to the power of flight which each species requires, for it is to the broad surfaces of the sternum that the great wing muscles are attached. Take the skeleton of a hum-ming-bird, which spends his life almost upon the wing. We find there a keel of so vast a size that the remainder of the skeleton is reduced to insignificance in comparison. In these researches one is soon struck by the fact that, in the modifications in various hones, or sets of bones, m accordance with the habits of each animal, the original type is never departed from, only modified. See, for example, the paddle of a whale, more like the fin of a fish in general appearance; and yet the same set of bones which are found in the arm of a man are again found' in an adapted form in the paddle of the whaler So, also, the foreleg of a horse preserves the same general plan. What is generally called his knee is in reality his wrist. It is there that we find the little group of bones w-liicli form the corpus. All below it anto our hand—a hand consisting of one linger. Take even a Wider instance. Onmnare the arm of a man and the wing of a bird. Still greater adaptations have taken place and yet the plan remains the same. We still find the clavicle or collar bone, the scapula or shoulder-blade, the humerus, ulna and radius, answering to the same bones of our arm, a small carpus or wrist, and finally the phalanges or fingers, simplified and lengthened and anchylosed to form but one series of bone, with the exception of a rudimentary thumb. It is not uncommon to find a rudimentary bone like this which, in some allied species, is fully developed. The leg of the horse again gives us a very striking example of this. There is, so to speak, only a single finger, but we find, one on each side of this little finger, two small bones, commonly known only as splint bones. These are the rudimentary traces of the same finger bones, which in the rhinoceros are fully developed. Now osteology abounds in wonderful forms of structure like these. It is a study pregnant with pleasurable results, and is a really profitable study, and one in which each fresh student may do real solid work. It is all the little facts observed by naturalists, from time to time, all over the world, which, on being collected together, form the nucleus of knowledge, for indeed all the scientific knowledge which we possess is little more than a nucleus with which we are supplied.— Science Oossip.