208 



BOTANICAL GAZETTE 



[march 



thickening had not begun in the new tracheids, but was noticeable 

 in the first of the new sieve tubes. Cutting II exhibited only 

 slight evidences of cell division, while in cutting III growth was 

 well started. No division had yet occurred in cutting IV. Growth 

 had been very rapid in cuttings I and III, as evinced by the absence 

 of thickening of the cell wall. This may be accounted for in part 

 by the high temperatures which prevailed between April 22 and 26. 

 During that period the mean daily temperatures ranged from 52° 

 to 70° F. Precipitation amounted to only 0.03 inch, but large 

 amounts of ground water were available at that season. 



TABLE C 

 Beginning op growth by cell division, tree i,- April 26, 1913 



To explain plausibly the conditions in cutting II, the point of 

 greatest growth the preceding season (table H), is not an easy 

 task. Every indication seems to show that we might expect most 

 rapid growth at this point. We can conclude only that the 

 restricted growth here denotes one of the many idiosyncrasies 

 of tree growth, where, as pointed out by Wieler (38), marked 

 differences may occur in closely neighboring spots. It is to be 

 expected that growth would not be manifest in cutting IV at this 

 early date, so we may conclude that in tree I cell division was in 

 evidence on April 26 in the upper portion of the bole but had not 

 yet begun at the base. 



In-order to check the results on tree I, four bole cuttings, 

 including the terminal leader and four branch cuttings, were made 

 on a neighboring tree on May 4, 1913, eight days later. Tree II 

 stood about 10 feet from tree I, and was apparently of the same 

 age and subject to the same silvicultural conditions. The extent 

 of growth and lignification in this individual is given in table D. 



