100 THE USE BOOK. 



heavy marking on all steep slopes and in exposed places must be 

 carefully considered. 



Each tree left should have its crown free enough for vigorous 

 growth. If usable, trees which have been badly crowded and 

 have only a small, sickly crown should be marked. 



When there are not enough young trees to form a good stand 

 in the future, seed trees must be left. These should be thrifty 

 and capable of bearing large quantities of seed at once. Occa- 

 sionally it will be possible to secure seed from trees too mis- 

 shapen or defective to be merchantable, but as a rule young 

 trees which will yield good lumber in the future should be 

 chosen. In mixed forests, all seed trees should be of the more 

 valuable species^ 



Where partial reproduction is already present, fewer seed 

 trees should be left than where there are no seedlings. If 

 there is danger that fire will run over the area, enough trees 

 should be left to seed the ground fully whether reproduction is 

 present or not. To give good results, seed trees of most species 

 should not be farther apart than twice their height, and should 

 be evenly distributed over the area. Always leave a number 

 of seed trees on the edge of openings, such as old burns, on the 

 side from which the prevailing winds blow. Do not mark 

 isolated thrifty trees of desirable species, unless it is evident 

 that the species will not grow well on that particular situation. 



Decide first which trees should be left, and then mark the 

 trees to be remoypy) If in doubt whether a tree is needed tor 

 oithnr noofl OIL protection., leave it. If in doubt whether a defec- 

 tive tree should be classed as merchantable, mark it. 



SUPERVISION. 



The Forest officer in charge of a sale must require full com- 

 pliance with all conditions of the contract. If any of the con- 

 ditions are found to be unjust or unreasonable, he should report 

 the facts, with his recommendations, in order that the written 

 contract may be modified. No Forest officer has or will be 

 given authority to allow the conditions of a contract to be 



