OLEORESm PRODUCTION. 



13 



about 5,300 cups, operated by this method, was separately recorded, 

 so that it could be compared with the yield obtained from the trees 

 on similar stands of timber adjacent, which were operated by the 

 two special methods under experiment, 



This operation was carried on for a period of two years. Figures 

 1 and 2 give the monthly observations on the five trees selected in 

 1916 and in 1917 (not the same five trees both years). The number 

 of tracheids counted in a radial direction across the ring indicates 

 the diameter increase since the beginning of the year. The fluctua- 



rfpr. MoyJun<iJo/y /U/o. 5<ipr. Oct Afov, Dec. Apr: May Jvtiq Ju/y Aoq. Svpl: Ocr A/ok Dec.: 



Number of tracheitis, observed April to 

 December ; in 1016, growth ring. "Sum- 

 mer wood present. 



Fig. 1.— Standard trees, 1916. 



Number of resin, centers per unit area 

 (an arbitrary tangential extent; diameter 

 of microscopic field by the width of the 

 annual ring observed). Observed April to 

 December; L916; in 1916, growing ring; in 

 1915, completed ring. 



tions in the number of resin passages present are also shown. In 

 Tables -2. and 3 are given the relative increases and decreases in width 

 of an mi ;il ring and percentage of summer wood as observed in 

 December, L916, in 50 trees chipped by each of the three methods 

 under observation arid in 20 unturpentined trees. In Table I are 

 given similar observations for the years 1015, 1916, and 1917. 



In 1910 Considerable variation was found in (lie number of trac- 

 heids observed from month to month in the specimens from the live. 



selected trees. (Fig. 1.) The width of the L916 annual ring in 

 the spec im ens cul bear fltt efld Of the season was m several cases 



87404°— 22 .'5 



