80 VITAL ACTIONS. 



bud, capable of forming other stems or branches like 

 that on which it appeared ; and each is protected and 

 nourished by a leaf which springs from the bark im- 

 mediately below the bud. Such leaf-buds are the 

 parts that enable a stem, when reduced to the state 

 of a cutting, to produce a new individual like itself; 

 and, without them, no propagation by portions of the 

 stem could take place. 



53. Leaf-buds are capable, under fitting circum- 

 stances, of growing when separated from their mother 

 branch, whether they are planted in the earth, or in- 

 serted below the bark of a kindred species. In the 

 former case, they emit roots into the soil ; in the lat- 

 ter, they produce wood, which adheres to the wood 

 on which they may be placed. Under ordinary cir- 

 cumstances, leaf-buds will not form anywhere except 

 at the axils* of leaves; but occasionally they appear 

 from other parts, such as the root, the spaces of the 

 stem which lie between the leaves (the internodes), 

 and even from the leaves themselves. In all such 

 cases, they are termed adventitious, because of the un- 

 certainty of their appearance. A very remarkable 

 state of them is the embryo-bud, a name applied to the 

 hnaurs, knurs, nodules, or hard concretions, found in 

 the bark of various trees, which seem to have, occa- 

 sionally, the power of propagating the individual, 

 notwithstanding their deformed and indurated 

 state. 



* The axil is the acute angle formed by a leaf and stem, at the 

 origin of the former; all bodies growing within that angle are said 

 to be axillary. 



