LETTER II. 



13 



along with other larches in a plantation, it reaches its 

 maturity, or becomes ripe," in seventy or eighty 

 years, and after that does no more good. But he will 

 himself observe also, that the history of a larch so 

 reared gives us no insight into its capacities for life 

 and growth, and will point to numerous examples of 

 larches growing singly and alone, which have already 

 lived twice that period, are still growing, fresh and 

 vigorous as ever, and are still enlarging in all direc- 

 tions. 



4. Systematic treatises on Botany may reasonably 

 be supposed to contain the wished-for information. It 

 will be found, however, that but little information is to 

 be had from them, and none that is satisfactory. For 

 the most part, the subject is passed over in silence; 

 or, if treated of, the observations made are of the most 

 meagre description. One of the fullest, and best, and 

 most recent — that by Professor Balfour of Edinburgh 

 — makes no other than a cursory allusion to it, brought 

 in, moreover, indirectly. There is still wanting defi- 

 nite information as to the age which trees attain. The 

 duration of their life has not been accurately deter- 

 mined. It exceeds so much the limit of man's life that 

 it is not easy to collect data on the subject. Some 

 exogenous trees attain a very great age. Trees, 

 which, in individual cases, attain great ages, belong to 

 the most different natural families. Among them may 

 be mentioned the Boabab, the Dragon-tree, species of 



