Page:Popular Science Monthly Volume 42.djvu/700

 680 most likely to meet with, at least a few specimens of a character to which reference has just been made.

These fossils were principally of water birds, having been discovered in the former bottoms of dried-up Tertiary alkali lakes, or upon the margins of those undergoing a similar process. With them were found immense numbers of arrow points of human manufacture, and the question had arisen as to whether it were not possible that they had been shot at the game during former times. To shed further light upon such an interesting subject, I most carefully examined each and all the specimens to discover if possible any healed wounds (fossilized) that may have been produced by such means. My interest in this matter was much stimulated by what Prof. Cope had formerly written in the American Naturalist for November, 1889. After describing the discovery of the bird-fossils referred to above, that eminent paleontologist there says that "scattered everywhere in the deposit were the obsidian implements of human manufacture. Some of these were, of inferior, others of superior workmanship, and many of them were covered with a patine of no great thickness, which completely replaced the natural luster of the surface. Other specimens were as bright as when first made. The abundance of these flints was remarkable, and suggested that they had been shot at the game, both winged and otherwise, that had in former times frequented the lake. Their general absence from the soil of the surrounding region added strength to this supposition. Of course, it was impossible to prove the contemporaneity of the flints with animals with whose bones they were mingled, under the circumstances of the mobility of the stratum in which they all occurred. But had they been other than human flints, no question as to their contemporaneity would have arisen" (page 979).

Now, I found no fossilized injuries of the bones in question that could be attributed to wounds of them that arose from arrow-shot; but, on the other hand, one or two pathological conditions of interest were discovered, and one of these a fracture in the course of healing.

In order to make clear the stage at which this healing fracture existed at the time of the death of the individual that sustained it, I will first offer a few remarks upon the course of such injuries in existing animals.

Fractured extremities of bones in both mammals (not including man) and birds are rarely kept quiet and properly approximated during the healing process, which takes place at the fractured extremities. This results in the formation of a "provisional callus" which soon surrounds the broken ends of the bones, and acts as an osseous splint, that strengthens with time.