500 Introduction to the Study of Science 



and the growing sprouts pulled and transplanted ; or they may 

 be grown from cuttings of the vines, or from sections of the 

 potatoes, as in the case of the common or Irish potatoes. 



Layering. Certain plants, like the strawberry, send out 

 runners or stolons which take root in the ground and eventually 



develop into complete and 

 independent plants. The re- 

 sult may be gained more 

 quickly by covering the tips 

 of the runners with soil, and 

 later separating them from 

 dlby seeds. 18 the parent and transplanting 

 the new plants. The black- 

 cap raspberry (Fig. 156) propagates itself in similar fashion, 

 and also by its seeds. The tips of its branches may be bent 

 over and covered with soil, and when rooted, cut from the 

 parent plant. 



The same method may be used in propagating the grape, 

 currant, blackberry, and other plants of like nature, also cer- 

 tain trees, as the apple, plum, and ejm. When a plant develops 

 roots with difficulty, the stem chosen is nearly severed from 

 the parent plant by an oblique cut, a V-notch, or it has a ring 

 of bark removed, where it is to be covered with soil. This 

 prevents the return to the tree of the sap, which is thus made 

 to accumulate at the wound, aiding in the development of 

 adventitious roots. The stem may be inclosed in a box filled 

 with soil. When it has well-grown roots, it is separated from 

 the parent and planted in good, moist soil. 



Cutting. Buds or twigs with buds of many plants may be 

 separated from the parent plant and used for propagation* 

 This method, known as cutting, is not so certain as layering, 

 because the cuttings often perish before developing roots 

 sufficient for growth. It is commonly known that willow 

 branches broken from a tree and stuck into the ground will 

 develop roots. Many other plants respond in a similar way, 



