COURSE OF Tl^E SAP. 



PT. II. 



shoot to the same size as the upper end of the lower 

 shoot. And I think it probable that each is of the 

 exact shape and size that nature formed it the first 

 year it grew. 



Again, you have only to examine a newly cut tree 

 of any sort, and, if sound, you will see the pith, though 

 around it you may count from 50 to 150 years' growth. 

 In drying, after the trees have been some time cut, small 

 cracks in the direction of the silver grain meet at the 

 pith, and prevent its being seen. This accidental disap- 

 pearance of the pith, immediately on the death of the 

 tree, is another corroboration of the vulgar belief of the 

 death and disappearance of the pith during the life of 

 the tree. Every innumerable small side-twig of every 

 innumerable small branch and root of the most gigantic 

 oak, gives origin to a new series of annual cones of 

 - growth ; and until internal death and decay supervene, 

 the first annual pith of the original seedling communi- 

 cates with these countless ramifications of branch and 

 root, and by its direct and lateral elongations passes, 

 through the tops of these innumerable myriads of cones, 

 to every side or leading bud, and to near the termina- 

 tion of every the finest ramification of the roots. 

 Whether Many of the older, and some existing physiologists, 

 of the lip"'* maintain that the upward sap is solely transmitted by 

 Z^noC^ the pith ; and the fact I have stated seems to favour 

 the opinion that the pith may play a prominent part in 

 supplying the bud, leaf, and new shoot with upward 

 sap : but how could the eleven layers of new wood. 



