i9 1 2] BROWN— PINUS RIGID A 397 



ciably, while greater increase of wood formation resulted as a 

 natural sequence. 



Before summing up the results of the preceding paragraph, some 

 observation on cessation of cambial activity should be given. It 

 has long been recognized that while cambial activity makes itself 

 manifest in many trees at about the same time, there is no relation 

 evident in its cessation. Thus Buckhout (2) found in Larix 



July 



form 



Hartig (6, 7) 



iber. R. 

 In beech 



it lasts 2.5 months, in oak 4 months, in Scotch pine and Norway 

 spruce 3 months. Friedrich (see Wieler 14), on the contrary, 

 claims that in coniferous and hard woods in general there are two 

 periods of growth, one lasting until about the end of May, sinking 

 until the middle of June, and reaching a maximum again in July. 

 Complete cessation resulted by the middle of August. The 

 majority of workers, however, unite with Hartig in saying that 



with 



cerned. 



In the present studies, the latest cuttings in 1909 were made 

 on July 6 upon tree III. At that time growth was still in progress 

 throughout. Comparing these with cuttings taken from the same 



tree on February 21 



following 



results are obtained. Cutting 2 showed 0.5 of the ring complete, 

 cutting 4, 0.6, cutting 8, 0.85. R. Hartig (6) agrees with T. 

 Hartig (8) that cessation of growth begins first in the crown in 

 trees in open stand and proceeds graduallv downward. If such is 



anoma 



was accelerated in the apical portions after June 15. However 

 some of Hartig's data are in accordance with that already given. 

 For example (Busgen 3), on June 21 the ring of an oak as compared 

 to that of a previous year gave the following data: 



At 1.3m. height o . 45 complete 



At 3.5m. height o. 45 complete 



At 5.7 m. height 0.45 complete 



At 7.9m. height 0.72 complete 



At 12.3 m. height 0.57 complete 



At 14. 5 m. height o. 56 complete (3-4 year branch) 



