124 



appreciable influence, and during which the synthetic activity 

 of the tree must have been greatly retarded. The year 191 1 was 

 marked by a more advantageous distribution of the rain, 3.59 

 inches falling in June and July, as compared with .8 of an inch 

 in the same part of the previous year, and this season's advan- 

 tages were clearly expressed in the ample growth of the shoots in 

 the following season. Likewise the season of 19 12 was an 

 exceedingly favorable one for forest vegetation in this region, as 

 testified by the excellent growth of all shoots in 1913. 



A series of observations of a similar nature was conducted also 

 on the Douglas fir, growing with the yellow pine in the same area 

 which furnished the data given in Table I. Twenty-three trees 

 were measured, these trees being of about the same age as the 

 pines. From the figures given it will be apparent that the com- 



Table IV 



Approximate Measurements of the Height Growth of Douglas Fir 



(Pseudotsuga taxifolia), made on the Upper Portions of the Main 



Stem, for Each of the Seasons Indicated, in Inches 



No. 



1909 



1910 



1911 



1912 



1913 



I 



12 



13 



8 



14 



12 



2 



6 



9 



6 



II 



II 



3 



13 



II 



10 



13 



12 



4 



13 



12 



13 



12 



10 



5 



II 



10 



12 



12 



12 



6 



13 



13 



10 



14 



14 



7 



14 



12 



8 



14 



14 



8 



II 



12 



II 



14 



12 



9 



8 



14 



13 



12 



8 



10 



8 



II 



8 



13 



12 



II 



13 



13 



13 



14 



13 



12 



13 



12 



12 



14 



14 



13 



10 



12 



13 



14 



12 



14 



12 



10 



6 



14 



13 



15 



16 



12 



6 



14 



16 



16 



12 



14 



10 



12 



12 



17 



IS 



14 



10 



14 



14 



18 



9 



8 



10 



12 



12 



19 



5 



8 



6 



10 



12 



20 



12 



II 



8 



10 



10 



21 



12 



8 



6 



13 



12 



22 



14 



13 



12 



IS 



14 



23 



10 



II 



8 



8 



12 



Total 



262 



263 



219 



293 



283 



Average 



11.4 



11.4 



9-5 



12.7 



12.3 



