igisl 



BROWN— PINUS STROBUS 



223 



results obtained from two cuttings in 1912 and the last two cuttings 

 of 1913. The table is of value because it offers comparative data 

 which are strongly correlated with the results of others. While 

 the periods of time between the cuttings of 191 2 and 1913 are 

 different, it is obvious that in each year the greatest increase of 

 xylem toward the end of the growing season was in the basal cutting. 

 In other words, growth continued vigorously at the base of the shaft 

 until well into September, while in the higher parts it had either 



TABLE K 

 Termination of growth, tree i; 191 2 and 1913 



totally ceased, as in cutting I, 1913, or continued very sluggishly,"^ 

 and this condition was exhibited by tree I during two successive 

 years. 



It follows from the preceding paragraph that in normal white 

 pine trees growth is apparently first retarded above, retaining its 

 vigor longest in the basal portions of the bole. The results of others 

 on coniferous species lead to the same general conclusion. T. 

 Hartig (12) worked on both hard and soft wood trees and came to 



13 The disparity in the data of cutting I for the two consecutive years may be 

 questioned. In 191 2 there was an apparent gain of 20 per cent during the period 

 intervening between the two dates given, whUe in 1913 no growth was evident at all 

 after the first date. But in 1912, the first cutting was made on August 5, while the 

 following year it was 8 days later. This probably accounts for the increase in the first 

 case. Growth was still in evidence there on August 5, but had the cutting been 

 made 8 days later, the results might have been decidedly different. 



