122 PROPAGATING BY LAYERS. [JULY. 



You will see the reason of this process : you 

 create a wound at a joint; and where plants 

 are wounded, many have a tendency to make 

 roots when covered with earth: so far this 

 process is the same as that which takes place 

 in a cutting, except that the cutting is entirely 

 separated from the parent plant. 



There are some plants, however, which will 

 not send out roots when entirely separated, 

 yet will strike when a wound is made, and the 

 communication and circulation are kept up with 

 the parent plant. This is called propagating 

 by layers. 



In many cases, plants will strike both from 

 cuttings and layers; but the latter are more 

 certain, because of the communication between 

 the old plant, which keeps alive the half sepa- 

 rated cutting until it has formed new roots on 

 the part divided* after which, the layer be- 



