48 A MANUAL OF FORESTRY. 



Quantity of Seed in 

 Pounds }>er Acre. 



Alder 15 



Silver Fir 40 



Larch ...... 14 



Spruce . . . . . . 10 



Scotch. Pine ..... 6 



In the case of partial sowing, the quantity of seed is 

 proportionately smaller, thus for 

 Sowing in strips, furrows, 



or ditches . about 65 75% of broadcast 



sowing. 



,, ,, patches 50 ,, ,, 



,, ,, pits or holes . . 25 35,, ,, 



4. Conditions of Germination. 

 The process of germination consists of the following : 



(1.) Swelling of the seeds ; 



(2.) Chemical change of the nourishing substances 



deposited in the seed ; 

 (3.) Development of the embryo. 



The swelling of the seed is due to the absorption of 

 water. If then a sufficient amount of heat and oxygen 

 are available, the reserve materials are changed into 

 soluble substances fit for the formation of new cells; 

 growth then sets in, which causes an enlargement of the 

 embryo, followed by the bursting of the shell of the 

 seed and the protrusion of the rootlet. 



The conditions for the successful germination of forest 

 seeds are thus : 



(1.) A constant but moderate supply of water ; 



V 



