Page:Popular Science Monthly Volume 17.djvu/385

Rh being disseminated but by the birds; these, swallowing the berries, use the pulp and cast the stone on branches of trees with bark suitable for their growth, where they take root and flourish. That the vitality of many seeds is not at all impaired by this process of passing through the stomachs of birds has been incontestably proved. Indeed, it is said that, when the farmers of some parts of England are desirous of making a hedge of hawthorn (Cratægus oxyocantha) grow in a short time, they feed the haws to their turkeys; the stones are rejected in the excrement, and when collected and planted a whole year is gained in the growth of the plant. It is also known by experiments that seeds in the crops of birds are not always injured; for the crop does not secrete gastric juice, and, as it is often not until twelve or eighteen hours after the act of swallowing that the food passes into the stomach, birds which are capable of rapid and prolonged flight could pass over a large tract of land or of sea. Passenger pigeons have been killed in the neighborhood of New York with their crops still full of rice collected by them in the rice-fields of Georgia and Carolina. As it is positively asserted that they will decompose food in less than twelve hours, they must have traveled three or four hundred miles in less than six hours. This is by no means an extravagant estimate, but rather under the mark. Falcons are reckoned the swiftest of all birds. It is recorded that one, sent from the Canaries to Spain, returned to the Peak of Teneriffe in six hours, a distance of about seven hundred and eighty miles. Seeds of wheat, oats, millet, Canary hemp, clover, and beet, germinated after being twelve to twenty-one hours in the stomach of birds of prey; and two seeds of beet germinated after having been thus retained for two days and fourteen hours. Seeds taken out of the crop of a pigeon, which had floated on artificial sea-water for thirty days, nearly all germinated. Hawks are always on the lookout for weary birds, those which have made long journeys; and pigeons and ducks coming from over the sea, as they are often known to do, would be easily caught and devoured by these birds. The bodies are devoured, and the contents of the crop perhaps scattered in a locality favorable to the development of any seeds which might be contained therein. Darwin forced seeds of various kinds into the stomachs of dead fish which were then given to eagles, storks, and pelicans. These birds, after an interval of many hours, passed the seeds in their excrement, or else rejected them in pellets, and several of them were then capable of germination. Some kinds, however, were invariably killed by the process.

Besides this method there is still another. This is by means of dirt or dried mud adhering to the legs and feet of birds. Still drawing on that cyclopædia of learning, Darwin's "Origin of Species," we read: