350 PHTTOLOGY. 



the quantity and size of the branches beyond, viz. in proportion to the 

 support wanted : therefore, if the branches are cut off from the trunk, 

 or the smaller branches from a larger one, the trunk or branch so de- 

 prived of their dependents will still only grow in proportion to the 

 decreased dependents. 



The leaves of trees increase the necessity of the growth of the stem 

 or trunk, without the necessity of increasing the number and size of the 

 branches ; so that the stem and the branches do not bear a due propor- 

 tion to one another, but the stem does to the leaves and branches taken 

 together. 



Whenever a tree, or probably any plant, throws out strong suckers, 

 or throws out new, strong, and healthy branches from the stem, be 

 assured that the top is not so strong as the bottom ; and that there is 

 not an equal quantity of life or powers of growth in both. It is on this 

 principle that those plants which are continued by suckers, produce the 

 suckers or new stem ; for if the old one was continued in full force, no 

 suckers would arise. This appears to be the case with partly full- 

 grown trees. A tree beyond a certain period begins to make shorter 

 shoots, and this goes on in a kind of inverse ratio to its age ; but if a 

 lateral branch shoot out from the stem, it grows luxuriantly like a 

 young shoot. Thus, when we see trees lopped up to near the top, the 

 side-shoots are strong, while the continued shoots of the top branches 

 are weak, just the reverse of a young tree. 



The lower a new branch arises the stronger it is, and in the same 

 proportion larger, from which principle a sucker is the strongest wood, 

 and is the longest and thickest. 



The branches of a tree on that side where there is something obnoxious 

 to their growth, such as high wind, too much sun, sea air, &c, do not 

 grow so strongly as they do on the other side of the same tree. I 

 suspect that this failure does not arise entirely from the branch itself, 

 but that the affected side of the tree has not powers equal to the oppo- 

 site side, so as to give sufficient nourishment to the branch. 



The great growth of every shoot is an elongation of the top ; but, 

 besides this, the part of the shoot that is already formed grows in all 

 its parts ; but that is only in proportion to the age of the part of the 

 shoot ; for the last-formed part increases most in itself, and gradually 

 less and less so to the setting on of the shoot, so that every part of the 

 shoot has always lost its power of growth within itself in proportion 

 to its age. This is the case with the fir, asparagus, Duke of Argyle's 

 tea \Lycium barbarum, L.]. 



The greatest growth among all the different shoots of a plant being 

 the top one, the next degree is in the branch immediately under the 



