2 28 General Botany 



of the upper buds, and in the spring the basal ends are warmed 

 first and start developing roots. Cuttings may also be kept over 

 winter in cool cellars in sand. In the spring the bundles are 

 taken up and the cuttings set about 3 to 4 inches apart in trenches, 

 with only the topmost end above the soil. The object of the 

 winter treatment is to allow the formation of a callus at the lower 

 end of the cutting. From this callus the first roots develop. 



Softwood cuttings. Cuttings or roses, geraniums, chrysanthe- 

 mums, coleus, and begonias are commonly termed ^ ' slips. ' ' These 

 are propagated in greenhouses and hotbeds under glass. Most 

 of the leaves are removed to prevent excessive transpiration and 

 wilting, and the cuttings are placed in rows in sand kept con- 

 stantly moist. Leaf cuttings are often used in propagating 

 begonias. Parts of leaves, or complete leaves, may be used, and 

 are simply laid on the surface of clean, moist sand. New plants 

 develop at the base of the leaf, or at the lower end of the principal 

 vein of a leaf segment. When the cuttings are transplanted, they 

 should be placed immediately in moist soil before the root hairs 

 are killed by drying. 



Grafting and budding. As pointed out in Chapter XVIII, 

 there are methods of propagating desirable varieties of a plant by 

 growing them on the roots of a less desirable variety. SeedHng 

 apple and pear trees occur everywhere and are almost invariably 

 worthless, but can be made to bear choice fruit by grafting twigs 

 from desirable trees on them when young. This is so easily 

 accompHshed that it seems a pity to find hundreds of these trees 

 along roadsides and fence rows bearing worthless fruit. 



By grafting standard apple, pear, cherry, peach, and apricot 

 cions on certain slow-growing stocks, with small root systems, 

 dwarf trees are produced. Apples, for example, may be dwarfed 

 by grafting them on " Paradise " stocks, pears on quince roots, 

 and standard cherries on native shrubby plums. The root 

 systems of these stocks, being small, decrease the water content 

 of the cion and use a smaller part of the food manufactured in 



