DEPLETION OF WILD LIFE 321 



transplant successfully, but are subject to diseases 

 of civilization. So far, with them, failure means 

 nothing except that the formula has not yet been 

 found to colonize successfully against modern con- 

 ditions which include the open season and the sur- 

 reptitious local rifle. Twenty years from now we 

 may be reproducing here and there, in small exam- 

 ples, the past. Meantime grizzly bears are not the 

 only American species apparently destined, for rea- 

 sons not yet scientifically determined, to extinction 

 in the United States. In the wildernesses of Alaska 

 and Canada they still apparently hold their own. 



Raising fur for the market is a new business 

 which may develop success and magnitude in our 

 Federal Lands. Silver fox farming is prospering in 

 a number of New England states and in northern 

 middle-west states. Successful blue fox farming is 

 adding a new industry to Alaska. Beaver may again 

 become a fur of reasonable price and popularity, for 

 aspen and willows, which are the beaver's principal 

 food, are rapid growers capable of cultivation to 

 any necessary extent in valleys where these animals 

 make their homes. There are still plentiful supplies 

 of beaver for stocking in the Great Lakes country 

 and our national forests and parks for that matter 

 in the Adirondacks and some parts of Pennsylvania. 

 Beaver are also valuable conservers of head waters, 

 for which alone they are worth preservation. 



Pine martin is another valuable fur which may 

 be developed commercially, lodge pole pine being a 



