60 PROPAGATION BY DIVISION. [CHAP. IV. 



from the parent, and replanting in good soil, to 

 make new plants. 



Layers. — Many plants, when kept in a moist 

 atmosphere, having a tendency to throw out 

 roots from their joints, the idea of making layers 

 must have very early occurred to gardeners. 

 When the roots are thrown out naturally 

 wherever a joint of the shoot touches the moist 

 earth (as is the case with most of the kinds of 

 verbena, which only require pegging down to 

 make them form new plants), layers differ very 

 little from runners ; but layers, properly so 

 called, are when the art of the gardener has 

 been employed to make plants throw out roots 

 when they would not have done so naturally. 

 The most common method of doing this is to 

 cut half through, and slit upwards, a shoot 

 from a growing plant, putting a bit of twig or 

 potsherd between the separated parts, and 

 then to peg down the shoot, so as to bury the 

 divided joint* in the earth (see Jig. 5.); when the 

 returning sap, being arrested in its progress to 

 the main root, will accumulate at the joint, to 

 which it will afford such abundance of nourish- 

 ment as to induce it to throw out a mass of 

 fibrous roots, and thus to convert the shoot 

 beyond it into a new plant, which may be sepa- 

 rated from the parent, and transplanted. A 

 verbena, or any other slightly-ligneous plant, may 

 be treated in this manner, but at the same time 

 it may be observed that it is scarcely worth 

 while to take the trouble of slitting the ver- 

 bena, as it will be sufficient to peg down a joint 

 in moist soil to induce it to send out roots. 



