Plate 32 



XSC i2-i-a. Branch section of Ciipressiis arizonica, cut October 11, 1941. Xylem 

 of 1937-1941- Typical pattern of thin and tliick gls giving a "fingerprint"; 

 dated multiplicity ; ddw ; psg. Frost effects with parenchyma and dw cells, 

 1938 ; frost spots, 1939 ; frost spots, 1940. The "fingerprint" — 

 1937 : A thick see. 

 1938 : A thick see. 



2 very tliin see (plus ddw). 

 1939: A thick see. 



A very thin see. 

 1940 : A thick see. 



2 very thin see. 

 1941 : A thick see ; cells of psg. 

 This pattern includes both intra-annual and annual gls. 



