46 .y of Propagation. 



Embryos, or germs, or latent shoots, exist then in every part 

 of the plant, and on the least irritation will be developed into a 

 state of active vegetation. Each separate branch and node of 

 stem is a distinct individual ; so that instead of being one, as we 

 generally recognize it, a tree is a vast assemblage of the same 

 species, treated as an individual while the mass of stems and 

 branches remains united, but no longer. The agriculturist is a 

 builder of vegetable cities and towns on a vast scale, accomplish- 

 ing his object by causing some of the inhabitants of one place 

 to remove to another, where they found separate communities 

 on their own account. His art consists of three parts : first, in 

 using means which give the germ he intends to remove or emi- 

 grate, a separate existence ; secondly, in weaning it from the 

 parent plant ; and thirdly, in providing for its wants until it can 

 shift for itself. 



There are three modes of multiplying plants by divisions : 



The first, by layers. 



The second, by scions or slips. 



The third, by grafts. 



In making a layer, you bend down a pliant branch without 

 separating it from the plant, and use some contrivance to fasten 

 it in the ground ; a slight incision is made at the spot where it 

 is confined. The irritation that ensues is generally sufficient to 

 occasion a small accumulation of sap, from which the germs of 

 several roots will shoot out ; when these have acquired a suf- 

 ficient power of independent existence, the connecting branch 

 is cut, and they are thus permanently separated. In doing all this, 

 the gardener but follows the indications which Nature points out 

 to him, for many creeping plants thus propagate themselves with- 

 out the aid of man. The lowermost branches which run on the 

 ground, are often covered with earth, washed over them by rain, 

 and being frequently wounded by some accidental causes, such 

 as gravel or pebble stones, the same irritation ensues, and the 

 same results follow that we have just described ; the connecting 

 branch, instead of being cut, is deprived of its nourishment by 

 the young plant, and thus rots and perishes. Laurels, and the 

 greater number of evergreen plants, are propagated by layers. 

 The same plan is pursued in vineyards. Comstock says, that a 

 branch of the vine is laid under ground, and the extremity of it 

 raised above the soil in that spot where it is wanted to produce 



