KNUDSON: CAMBIUM DEVELOPMENT IN AMERICAN LARCH 285 



was removed. The removal, as before, was made from the south 

 side of the tree. The branches were numbered according to their 

 position on the tree, the topmost branch being No. I, and the 

 basal branch No. 7. From the individual branches there was 

 removed from each season's growth a cutting; from the topmost 

 branch two such cuttings were removed and from the basal branch 



TABLE VIII 

 NUMBER OF ROWS OF XYLEM CELLS AND DIAMETER INCREASE OF XYLEM TISSUE IN 



THE CUTTING FROM LATERAL BRANCHES OF TREE E 



seven cuttings. These cuttings were fixed, sectioned, and pre- 

 pared as before. In the following table the figures given refer 

 only to the number of cells in the new xylem layer and to the 

 diameter of that tissue. The diameter increase over the entire 

 tree is represented in DIAGRAM in. 



