208 SPRING. 



proof that the twigs, though a good deal browned in 

 the bark, were not dead. When the trees began to 

 vegetate for the season, the young leaves and shoots 

 of the aucuba japonica came out first and most vigo- 

 rously at the top and upper parts of the tree ; those of 

 the holly came out equally all over ; but, on the 

 laurel, the young shoots were six inches long upon the 

 lower parts, before the buds upon the twigs that had 

 been injured were the size of pin's heads. Upon an- 

 other laurel of the same age and in the same soil, but 

 which had not been hurt by the winter, the action of 

 all the buds was simultaneous. These simple facts 

 are not consistent with any theory of the ascent of the 

 spring sap from the roots through the wood ; and as 

 little have we been able to find any thing but evidences 

 against the descent by the liber ; and therefore, what- 

 ever substances the plant may take in from the soil, 

 from the atmosphere, or from both, there is no proof of 

 a general circulation. There is a general action of the 

 tree, and an annual formation of new matter, in elong- 

 ated shoots, leaves, blossoms, seeds, wood, and roots ; 

 but the probability is, that all these, and all the parts 

 and substances that can be produced by a vegetable, 

 are developments and augmentations of substances that 

 are already there. It is the same with the parts of an 

 organic body as with the whole of it, there must be a 

 germ ; and though external circumstances may modify 

 the development of that, much more in the case of a 

 plant than in that of an animal, they can do nothing 

 without the germ, and there is always a limit to the 

 modifications. 



One part of the subject is a little perplexing, and 



