METHOD OF DIFFUSION. 23 



porter's native place, or through distrust of the kind of Sparrow already 

 imported, which, unfortunately, was widely known from the first as 

 the English Sparrow. We can never know how many separate impor- 

 tations were thus made, nor how many thousands of individuals were 

 introduced, but it is certain that the number of places thus supplied with 

 birds is much greater than has been supposed, and considering this fact 

 and the rapid rate at which the Sparrow breeds, we ought not to won- 

 der that it has so completely overrun the country. 



METHOD OF DIFFUSION OF THE SPARROW. 



In the ninth edition of the Encyclopedia Britaunica the distinguished 

 ornithologist, Prof. Alfred Newton, makes the following statement : 



The House Sparrow is far too well known to need any description of its appearance 

 or habits, being found, whether iu country or town, more attached to human dwell- 

 ings than any other wild bird; nay, more than that, one may safely assert that it is 

 not known to thrive anywhere far away from the habitations or works of men, ex- 

 tending its range in such countries as Northern Scandinavia and many parts of the 

 Russian Empire as new settlements are formed and land brought under cultivation. 



Thus questions arise as to whether it should not be considered a parasite through- 

 out the greater portion of the area it now occupies, and as to what may have been its 

 native country. Moreover, of late years it has been inconsiderately introduced to 

 several of the large towns of North America and to many of the British colonies, in 

 nearly all of which, as had been foreseen by ornithologists, it has multiplied to excess, 

 and has become an intolerable nuisance, being unrestrained by the natural checks 

 which partly restrict its increase in Europe and Asia. 



This statement of the Sparrow's relations to man is unquestionably 

 true wherever the bird is known, and hence in America we should not 

 expect to find it except in settled portions of the country. Tbe manner, 

 however, in which it overruns a new country to which it is introduced 

 differs somewhat from the way in which it extends its range in 

 older countries as the area of cultivation is extended. In America, 

 the method by which the Sparrows spread without the direct aid ot 

 man is peculiar. They first invade the larger cities, then the smaller 

 cities and towns, then the villages and hamlets, and finally the populous 

 farming districts. 



As the towns and villages become filled to repletion the overflow moves off into the 

 country, and the Sparrow's range is thus gradually extended. Occasionally, how- 

 ever, it is suddenly transported to considerable distances by going to roost in empty 

 box-cars and traveling hundreds of miles. When let out again it is quite as much at 

 home as in its native town. In this way it reached St. John, New Brunswick, in 

 1883, on board the railroad trains from the west. Iu like manner another colony ar- 

 rived March 1, 1884, in grain cars from Montreal. Similarly it has appeared at a 

 number of towns in the United States. (Hoadley MS.) 



The cities and towns first invaded by the Sparrow (of course exclud- 

 ing those where they are actually carried by men) are iu most cases 

 railroad towns ; and especially in the West there is no doubt that the 

 great railways along which vast quantities of grain are transported have 

 been so many great highways along which the Sparrows have traveled 

 slowly from place to place. More or less scattered grain is always to 



