FUNCTION.] GENERAL CONSIDERATIONS. 137 



At the end of the year the same phenomena occur as took 

 place the first season : wood is gradually deposited by slower 

 degrees, whence the last portion is denser than the first, and 

 gives rise to the appearance called the annual zones : the new 

 shoot or shoots are prepared for winter, and are again 

 elongated cones, and the original stem has acquired an 

 increase in diameter proportioned to the quantity of new 

 shoots which it produced, new shoots being to it now, what 

 young leaves were to it before. 



IV. The third year all that took place the year before is 

 repeated ; more roots appear ; sap is again absorbed by the 

 unfolding leaves; and its loss is made good by new fluids 

 introduced by the roots and transmitted through the alburnum 

 or wood of the year before ; new wood and liber are formed 

 from matter sent downwards by the buds ; cambium is exuded ; 

 the horizontal development of cellular tissue is repeated, but 

 more extensively ; wood towards the end of the year is formed 

 more slowly, and has a more compact character ; and another 

 ring appears indicative of this year's increase. 



In precisely the same manner as in the second and third 

 years of its existence will the plant continue to vegetate, till 

 the period of its decay, each successive year being a repetition 

 of the phenomena of that which preceded it. 



V. After a certain number of years the tree arrives at the 

 age of puberty ; the period at which this occurs is very 

 uncertain, depending in some measure upon adventitious 

 circumstances, but more upon the idiosyncrasy, or peculiar 

 constitution, of the individual. About the time when this 

 alteration of habit is induced, by the influence of which the 

 sap or blood of the plant is to be partially diverted from its 

 former courses into channels in which its force is to be applied 

 to the production of new individuals rather than to the 

 extension of itself ; about this time it will be remarked that 

 certain of the young branches do not lengthen, as had been 

 heretofore the wont of others, but assume a short stunted 

 appearance, probably not growing two inches in the time 

 which had been previously sufficient to produce twenty inches 



