Bericht über das permanente internationale ornithologische Comite. 65 



In the investigation of Economic Ornithology still 

 other questions present themselves. Among them may be 

 mentioned : 



At what season, and for how long a period, is the 

 bird with us ? 



How many broods does it rear each season? 



Does it inhabit marshes, uplands, cultivated fields, or 

 forests ? 



Does it take up its abode near the habitations of man, 

 or does it inhabit districts remote from civilization? 



What effect does the settlement of a region have upon 

 its bird-life ? 



What birds if left to themselves, are likely to become 

 most abundant as the country grows older? 



In the pursuance of these researches it is evident that 

 niuch good would ^result from friendly Cooperation with 

 the Entomological and Botanical Divisions of the Depart- 

 ment of Agriculture, and with the United States Entomo- 

 logical Commission. 



B) The Distribution of Species, studied as a branch of 

 Economic Ornithology, is a subject of great importance, 

 both from a scientific and a purely practical Standpoint. It 

 deals not only with the distribution of birds, but also with 

 the distribution of certain insects and plants, aiming to 

 show, by means of coloured maps, the areas inhabited by 

 those species which, from their injurious or beneficial qua- 

 lities, or from their relations to certain industries, are of 

 economic importance to man. 



The causes which influence and restrict the dispersion 

 of animals and plants, and determine the boundaries ofthe 

 regions which they inhabit, will also be discussed. Tem- 

 perature, humidity, altitude, minor physiographical conditions, 

 and food-supply, may be classed under this head. 



The practical bearings of this investigation are not 

 obscLire. When the limitations of the several Faunal Areas 

 have been ascertained with sufficient exactness to admit of 

 graphic Illustration by means of coloured maps, it will be 

 possible to predict, with considerable accuracy, the course 



Ornis. I. 5 



