l80 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I40 



XSP 1-2 (table 130) was cut off February 22, 1941. The "com- 

 plete entire" growth layer of 1940 has weak, intermittent densewood. 

 At the gaps, the cells give no indication of narrowing as is to be ex- 

 pected in the development of normal densewood. Although the annual 

 increments in the Experiment Station pines possess multiplicity, it is 

 not so great as in the Arizona cypresses. 



Table 130. — XSP 1-2 

 4S cm. 16 cm. TF 



1937 I see 



1938 I see 



ddw 



1939 I see 



1940 2 see 



I sL 

 I ce 



Table 131. — XSP 2-1 



42 cm. 32 cm. 20.5 cm. 



1936 2 see I see 



I dL 



1937 I see I see i see 



ares 



1938 2 see 2 see 2 see 



ddw 2 dL 



1939 I see I see i see 



I dL I sL I see 



1940 inc ine i sL 



inc 



Table 132. — YCt 1-4 



12 cm. 5.5 cm. TF 



1940 2 see I see i 



XSP 2-1 (table 131) was frozen artificially at 32 cm. on May 10, 

 1940, and was cut off June 12, 1940. In the 1937 increment, the arcs 

 are of densewood confined to the long radius. 



Branch YCt 1-4 (table 132) came from a single tip flush which rep- 

 resented the entire growth for 1940. 



Branch YCt 1-5 (table 133) possessed two tip flushes for the growth 

 of 1940. Sections at 15 cm. came from the inner, and those at 12 cm. 



