238 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I40 



Two tip flushes are not recorded by sharp growth layers in 1942 

 (i sce+i dee), but two annual tip flushes correspond to four sharp 

 diameter flushes in 1943 and 1944 (i sce+i sL and i sce+i sL+i 

 dL). 



TTP 20-i8-a {1940-19 42) 

 3 see + 2 dee — 3 tfs — 3 years. 



TTP 20-23-a (1943-1944) 

 3 see + inc — 2 tfs — 2 years. 



Tip growth of TTP 20-23 was measured January 30, 1943, Febru- 

 ary 5, 1944, and November 14, 1944. For each year included, 1943 

 and 1944, one tip flush was formed. In the 1943 increment, one 

 diameter flush was made and in 1944, two diameter flushes. This is 

 measured multiplicity, not only in sections a taken from the 1943 tip 

 growth, but also in sections b taken from 1944 tip growth. Two diam- 

 eter flushes correspond to one tip flush. In TTP 20-25, also with 

 measured tip flushes, two diameter flushes correspond to two tip 

 flushes. 



TTP 20-2 5-a (1943-J944) 



3 see— 3 tfs— 2 years. (See table 75, p. 145.) 



TTP 20-27-a (1943-1944) 

 2 see -{- I dee — 3 tfs — 2 years. (See table 76, p. 146.) 



TTP 20-33-a {1943-^944) 

 2 see -1" I dee -\- ddw — 3 tfs — 2 years. 



TTP 20-34-a (1943-1944) 

 2 see -|- 1 dee -f- 1 dL -j- i d are — 3 tfs — 2 years. 



TTP 20-36-a (1943-1944) 

 2 see -f- 1 psee -}- i dee- 3 tfs— 2 years. (See table 81, p. 149.) 



The branches of TTP 20 illustrate the variety to be found among 

 growth layers, tip flushes, and diameter flushes. 



TTP 2i-i-a (1936-1940) 



5 see -}- I msec + i psee -f- 1 ine L — 6 tfs — 4* years. 



The increments for the years 1936 and 1937 have 2 see each whereas 

 1939 has I msce and 1940 has i psee -I- inc L. 



TTP 2i-2-a (1937-1940) 



6 see -H I dgl -}- i dL -f ares — 5 tfs — 3* years. 



