388 THE LENGTH OF PLANT LIFE. 



perfection. By some this may be referred to the 

 change which has taken place in the climate, to the 

 felling of the forests ; but this cannot fully account 

 for it, because in new parts of the country, where 

 these forests remain standing, it is the same misera- 

 ble fruit when compared with its former beauty and 

 excellence. The White Doyenne, or St. Michael, 

 was once universally fair and beautiful ; but in the 

 most favored districts it is every year becoming more 

 and more subject to the diseases which have expelled 

 it from other regions. 



We are aware that this limit to the life of varie- 

 ties is denied by many able men, who state that 

 disease rather than decrepitude is the cause of their 

 disappearance : yet does not disease in these cases 

 result from a weak state of the system on account 

 of old age 1 Much room has been left for argument 

 to those who oppose this theory, because many who 

 have upheld it have endeavored hypothetically to 

 state the exact life of varieties. This in some cases 

 has been proved by actual experience to be false, 

 which has cast obloquy upon the theory. It would 

 be as difficult to state exactly the limit of plant-life 

 as of that of man. That of the latter is put down, 

 in a general way, at threescore years and ten ; and 

 yet, by great care, and through the possession of a 

 strong constitution, some men live to half as much 

 more, while thousands die in infancy. Just so some 

 seedlings do not have sufficient strength to survive 



