74 NEW YORK STATE MUSEUM 



Tree 7 was a red oak with a diameter of 1 J inches. On May 29th 

 the foliage was much retarded in development, the leaves being less 

 than one-fourth the norm.al size and the inner bark showing a variable 

 amount of penetration and injury. On June 28th one limb was 

 dead and the leaves on the others were only one-half the normal size 

 and pale green. The inner bark showed a little discoloration. On 

 November 10th this tree was still alive though the oiled portion of 

 the bark was manifestly browner and m.ore discolored than that 

 which was not treated with the insecticide. 



Tree 8 was a red maple with an approximate trunk diameter 

 of ij inches. On May 29th the oil had penetrated the bark very 

 little or not at all and the foliage appeared to be normal. On 

 June 28th the foliage was yellowish green and possibly somewhat 

 abnormal. The inner bark was hardly discolored. On November 

 10th this tree was alive though the bark showed a deep and marked 

 discoloration in spots, in certain sections this evidently extending 

 to the sapwood and in some instances probably into it, in somewhat 

 the same m.anner as recorded above for the cut red maple limb. 



Tree 9 was a large hornbeam with a diameter of about 2 inches. 

 On May 29th there was very little evidence of penetration of the bark 

 by the oil and the foliage appeared to be normal. On June 28th the 

 inner bark was possibly somewhat discolored though the foliage was 

 norm.al or nearly so. On November 10th the tree was alive though 

 apparently with some discoloration of the inner bark. 



Tree 10 was a large hornbeam with a diameter of 2 inches. On 

 May 29th there was very little penetration of the bark by the oil 

 and the foliage appeared to be normal. On June 28th the inner 

 bark was possibly somewhat discolored and the foliage normal 

 or nearly so. . On November 10th there was apparently some dis- 

 coloration of the inner bark by the oil. 



It will be noted that six out of ten trees died within six months 

 after the treatment and under conditions which hardly justify any 

 other verdict than that of death as a result of oil injury. It is true 

 that ordinarily much larger trees would be treated with this or similar 

 preparations and therefore the probabilities of injury would be less, 

 owing to the thickness of inert outer tissues which must be penetrated 

 before the oil can invade the living and necessary vital cells of the 

 inner bark and outer sapwood. It is well known that a heavy 

 lubricating oil, the green grease of the machinist or the anthracene 

 of the chemist is a very dangerous material to apply to the trunks of 

 trees, and in a preparation containing such a high percentage of this 



