36 PLANT LIFE ON THE FARM. 



stems, like those of fruit or timber trees or shrubs, and the 

 duration of whose existence may be counted by years, and 

 often by centuries. Then, again, there is an intermediate 

 class of cases where the root- stock remains below-ground 

 for a period long enough to justify the term perennial, 

 while the branches or shoots die down after the seed is 

 ripe, or are killed to the ground by a touch of frost, as in 

 the common nettles. 



Buds, Branches, Tubers, &c The branches or sub- 

 divisions of a stem originate as buds or "eyes," which are 

 placed at the free ends of the stem or of its branches, or 

 which originate from the side of the stem or branch, in 

 what is called the " axil " of a leaf, or of a leaf-scale, the 

 axil being the angle formed by the base of the leaf at the 

 point where it springs from the stem. The traces of their 

 origin are often lost as the plant grows, but the rule is, as 

 it has been stated, subject to a few exceptions of no moment 

 for our present purpose. It is not usual for a bud to be 

 borne in the axil of every leaf, far from it, but this is the 

 place where the side-buds when they do exist are almost 

 sure to be found. The shoots which " tiller " up from the 

 base of the stems of the wheat originate as buds from the 

 axils of the lower leaves, while the upper ones are des- 

 titute of them. When a tree is "pollarded," a large crop of 

 buds makes its appearance ; and the multiplication of some 

 weeds, like thistles and bindweed, after their stocks have 

 been cut through with the hoe at insufficient depths below 

 the surface, is due to a like formation of buds. 



The tuber of the potato may be mentioned under this 

 heading. Though commonly called a root, because it 

 happens to grow below-ground, it is clearly a stem, because 



