930 



SCIENCE. 



[N. S. Vol. XVII. No. 441. 



food habits of birds with respect to agri- 

 culture and horticulture ; and the section of 

 game preservation and introduction, which 

 has jurisdiction over matters covered by 

 the provisions of the Laeey Act, and also of 

 the game laws for Alaska. 



The Biological Survey proper carries on 

 field explorations in all parts of the coun- 

 try, but does most of its detailed work in 

 the west. It collects data and prepares 

 maps showing the actual distribution of 

 various species of mammals, birds, reptiles, 

 trees and shrubs, and determines the 

 boundaries between the several life zones 

 and areas. By a study of the associations 

 of species distinctive of the several zones 

 in connection with the crops found to 

 thrive best in parts of these zones, it pre- 

 pares lists of the particular varieties of 

 fruits and other agricultural products 

 adapted to each belt. 



The section of economic relations, by 

 studying the food habits of birds in the 

 field, and the stomach contents of birds in 

 the laboratory, determines the economic 

 status of various species of importance 

 from the standpoint of practical agricul- 

 tiu'.e. Birds are studied by species and 

 groups, and an effoi-t is made to ascertain 

 the food of each species during each month 

 in the year and from different parts of the 

 birds' range throughout the United States, 

 so that the results arrived at may be au- 

 thoritative and final. Among the groups 

 thus far treated are the hawks and owls, 

 crows, blackbirds, orioles, cuckoos, shrikes 

 and sparrows. 



The section of game protection and pre- 

 servation inspects importations of live 

 birds and mammals from foreign countries 

 in order to prevent the introduction of nox- 

 ious species, such as the mongoose, the large 

 fruit-eating bats, the starling, kohlmeise, 

 and others, and gives permits for the intro- 

 duction of non-harmful species. It. has 



charge, also, of matters of federal game 

 protection and the interstate commerce in 

 game shipped in violation of state laws. It 

 publishes digests of the state game laws and 

 laws for the protection of birds other than 

 game birds, and other literature bearing on 

 the general subject of game protection. 



The Economic Value of the Remaining 



Puhlic Land: J. D. Whelpley, AVash- 



ington, D. C. 



The land office of the United States has 

 had under its control for disposal under 

 such laws as have prevailed from time to 

 time an area probably amounting to about 

 one billion five hundred million acres of 

 land. About one billion acres of this land 

 have passed from government to private 

 ownership. About five hundred million 

 acres remain subject to the law of congress. 



The economic value of the one billion 

 acres which have already been disposed of 

 has been fully demonstrated. The world 

 power of the United States as a nation has 

 become great in direct ratio to the develop- 

 ment of the natural resources of the public 

 lands. The tremendous increase in wealth 

 resulting from the rapid settlement of the 

 one billion acres of public land has blinded 

 the people of this country to the serious de- 

 fects which have existed in the laws gov- 

 erning the disposal of the same. 



Not one hundred million acres of the 

 five hundred million remaining are suitable 

 to profitable and comfortable occupation 

 by American citizens under existing eco- 

 nomic, physical and social conditions. It 

 is now generally recognized that it is of 

 supreme importance that the government 

 should intelligently conserve the possible 

 economic values of that area of the United 

 States which is still included within the 

 limits of the public domain. Room is 

 needed for more population, more raw ma- 

 terial is necessary to maintain our manu- 

 facturing industries, and one homesteader 



