XUIi-jyUXS AND LAYERS 369 



the cane striking, the ground and taking root, as 

 shown in Fig. 388. A stolon is not prostrate 

 throughout its length, but makes a high loop be- 

 tween the parent plant and its contact with the 



Fig. 388. 

 Stolon of black raspberry. 



earth. The shoots which become stolons are at 

 first upright, but the weight of the branch forces 

 the end to the ground. 



461a. The praotioe of layering consists in bending down branches 

 and covering them with earth at the points from which it is de- 

 sired that new plants arise. Horticulturists make no distinction in 

 terminology between prostrate layers, like that in Fig. 386, and 

 stolons. In plants which root with difficulty, the horticulturist outs 

 through the bark, or breaks it, at the covered points, for roots 

 usually start more readily from wounded surfaces. 



462 We have already studied the house -leek 

 (Fig. 372), and have observed that it propagates 

 by offsets. An offset differs from a layer in the 

 fact that it is prostrate from the beginning, and 

 from a runner because it usually makes but one 



