442 



Illinois Natural History Survey Bulletin 



Vol. 23, Art. 



surface of the dye was not extensive but 

 was similar in both trees. In one tree the 

 dye extended in its upward spread from 0.3 

 inch in 1938 wood to 16 inches in 1943 

 wood. It extended in its downward spread 

 from 2 inches in 1941 wood to 5 inches in 

 1943 wood. The dye did not penetrate 

 1937 and older wood above the hole or 

 1940 and older wood below the hole. It 

 spread laterally beyond the hole 0.1 inch 

 in 1943 to 1941 wood. 



With the injection method, penetration 

 of the dye w^as more extensive than in the 

 test described in the preceding paragraph. 

 The dye in one tree extended in its upward 

 spread from 24 inches in 1939 wood to 36 

 inches in 1942 wood. It extended in its 

 downward spread from 6 inches in 1938 

 wood to 12 inches in 1942 wood. It spread 

 only in the midsummer and late summer 

 portions of the 1938 wood, and laterally 

 beyond the injection hole from 0.1 inch 



