196 



APPLICATION OP PRINCIPLES. 



surface; and as the stem is the only part upon which 

 buds certainly exist, so the stem is the only part from 

 which cuttings should be prepared. And again, as the 

 internode, or that space of the stem which intervenes 

 between leaf and leaf, has no buds, their station being 



confined to the axil of 

 the leaves, a cutting pre- 

 pared from an internode 

 only is as improper as 

 one from the root. It 

 is no doubt true, that 

 we constantly propagate 

 plants from pieces of 

 what are called roots, as 

 in the Potato, or the Scir- 

 pus tuberosus (Jig. 19) ; 

 but such roots are, in 

 reality, the kind of stem called a tuber (51) ; and, in 

 like manner, other cases of similar propagation are 

 also successful, because the part called a root is, in 

 reality, an underground stem covered with the rudi- 

 ments of leaves, to each of which an eye belongs. 

 The Eose, the Lilac, and many other plants, have 

 subterranean stems, cuttings of which will there- 

 fore answer the purpose of propagation. It will 

 also occasionally happen, that, owing to unknown 

 causes, morsels of the true root will generate what 

 are called adventitious buds ; and hence we do 

 occasionally see the root employed for propagation, 

 as in Cydonia japonica ;* but these are rare and ex- 

 * Also the Paper Mulberry, the Paulownia, Ac A J. D. 



