ON CAMBIUM. 87 



intersected bark, cause an annular protuberance. The 

 descent of the cambium thus being obstructed, it will ac- 

 cumulate in that part of the tree above the intersection, 

 afford it a superabundance of nourishment, creating a 

 proportional vigor of vegetation, and a corresponding 

 excellence and profusion of produce. 



Emily. Would it not then be a good mode of improv- 

 ing the produce of fruit-trees ? 



Mrs. B. This operation, which is called ringing, has 

 been tried on the branches of fruit-trees, and, I under- 

 stand, often with success ; but I should conceive that 

 the tree must be ultimately injured by the operation ; for, 

 if you confine to one part of a plant the food which was 

 destined for the nourishment of the whole, you interfere 

 with the order of that wisest and best of agriculturists 

 Nature. When interrupted, however, in her original 

 course, she is fertile in expedients to accomplish by col- 

 lateral means her destined purposes. I observed that 

 some small portion of the cambium descended through 

 the alburnum, which is contiguous to the liber. When 

 the annular section is made on a branch, a much more 

 considerable quantity forces its passage through this 

 channel, and, by affording the young wood an unusual 

 supply of nourishment, renders it harder and heavier be- 

 low than above the intersection. 



Caroline. But if the vegetation of the tree above the 

 annular section is improved, and the wood beneath it 

 better nourished, what part of the plant suffers by this 

 operation ? 



Mrs. B. Not any part during the season the annular 

 section is made ; the evil is reserved for a later period, 

 as I shall explain to you. 



The cambium being thus diverted from its course, the 

 greater part being forcibly detained above the annular 

 section, and what little makes its escape descending 

 through another channel, the bark is wholly deprived of 



473. What will be the effect if a ring be cut completely round a tree 

 when the cambium is descending 1 ? 474. Has it been thought that 

 fruit trees have been benefited by this mode of ringing. 475. When 

 the cambium is thus interrupted, what other mode of descent is there 1 ! 

 476. How is the quality of the wood affected by ringing! 477. 

 What parts of the tree are not annually formed from this interruption of 

 cambium 7 



