GENERAL CONSIDERATIONS 239 



space in Schlich's Manual, Vol. IV, devoted to the considera- 

 tion of forest fires. Out of approximately 600 total pages 

 less than 20 pages are occupied by fire protection. In America 

 this line of protection at the present time receives primary 

 consideration. While the emphasis placed on the various 

 branches of protection will shift from country to country, yet 

 it is true that the same kind of injurious agencies described 

 by Fisher ^ and Hess are to be encountered in America. Much 

 can be learned from these two standard works. 



The four most important agencies against which forest 

 protection is required in America are: 



Fires 



Insects 



Fungi 



Grazing animals (domestic). 



Forest protection in its appUcation to the control of injurious 

 agencies and the prevention of losses is a highly specialized 

 subject (or group of subjects). The classification and de- 

 scription of injurious agencies, the scientific facts which must 

 be known in determining control methods and the adminis- 

 trative problems connected with control and prevention of 

 losses call for the development of speciaHsts in several of the 

 more important branches of forest protection. 



It is impossible (and out of place) within the limits of a 

 work on general silviculture to treat fully of forest pro- 

 tection. 



All that can be attempted here is to select the more de- 

 structive injurious agencies and to present (in the succeeding 

 chapters) for each the following information: 



(a) Description of the damage caused. 

 {b)' Character of the injurious agency. 



