digious size of the area it has overspread are without parallel in the history of any bird. Like a noxious weed transplanted to a fertile soil, it has taken root and become disseminated over half a continent before the significance of its presence has come to be understood. The explanation of this phenomenal invasion must be found in part in the direct assistance given by man in carrying it from place to place intentionally; in part in the peculiar impetus usually given prolific species when carried to a new country where the conditions for existence are in every way favorable; and in part in its exceptional adaptability to a diversity of physical and climatic conditions. This adaptability has enabled it not only to endure alike the tropical heat of Australia and the frigid winter of Canada, but to thrive and become a burdensome pest in both of these widely separated lands.
At first sight it seems difficult to understand why man should have taken so much interest in this bird, and aided in its rapid increase and spread ; but the consideration of a few points bearing upon the matter will render the case more intelligible.
A considerable part of our population, and especially that of the newer parts of the country, consisted of Europeans who naturally remembered with pleasure many of the surroundings of their former homes and doubtless often longed for the familiar chirp of the Sparrow. They had no strong associations connected with our American birds, and our treeless cities and uncultivated prairies contrasted strongly with the thickly settled country—half garden, half city—which so many of them had left. So, as opportunity offered, small lots of Sparrows and other European birds were brought to this country; or after the Sparrows became abundant in our Eastern cities they were carried inland to a large number of different places. There is little doubt that if we could obtain the data relating to the introduction of Sparrows at all points where they are now found in the Mississippi Valley, we should find that by far the larger part of these introductions had been accomplished by English, German, and French citizens, inspired by the recollections of the birds of their fatherland.
In addition, the prevailing ignorance of the average American citizen with regard to our native birds, joined to the totally erroneous, or at least grossly exaggerated, reports of the benefits conferred by the Sparrows in New York, Philadelphia, and other Eastern cities, tended to increase the interest which naturally attached to an imported bird, until many persons went to the expense of purchasing and shipping Sparrows to considerable distances in the belief that they were insectivorous birds and must prove beneficial wherever they could be naturalized. In this way a veritable Sparrow "boom" was started, and the price of Sparrows in New York went up to such a point that many people desirous of obtaining the birds found it cheaper club together and import them direct from Europe; while in many cases this was doubtless done from the desire to obtain birds from the neighborhood of the im-
