Plate 9 



Fig. I. TTC i2-g-b. Branch section of Cuprcssus ari::oiiica. cut February 29, 



1940. Xylem of I933( ?)-i939. Dated multiplicity; curtains. 



1933 : psce, see. 



1934-35 : Natural frost circle ; several psce ; 3 see. 



1936 : Natural frost spots ; 2 see. 



1937: Natural frost spots; psce; msce ; see; msce curtain; see. (See fig. 2, 

 below, for detail of curtain.) 



1938: Thin see; sharp curtain grading into psce; see. 



1939 : Circle of natural frost effects ; see. 

 Fig. 2. TTC i2-g-b. Detail of mid-1937 on figure i, above. A thick gl with thin 



dw, a thin gl, and a thin gl with poorly developed dw giving a curtain effect 



to the preceding gl. 



Plate id 



Fig. I. TTC i2-i2-h. Branch section of Cuprcssus arhonica, cut July 31, 1944. 



Xylem of 1943-1944. ^Multiplicity proved by tip-flush measurements; ddw 



and initiation of lensing. 



1943: see (at center) ; psce with psL; see with ddw. 



1944 : msce with ddw grading into lens and with intermittent densewood ; 

 see probably ; inc L's. 

 Fig. 2. TTC 12-14-b. Branch section of Cuprcssus arizouica, cut November 17, 



1945. Xylem of 1942-1945. Outer margin of xylem made irregular by a 



striking example of psg ; thread of ilw ; thin dw ; idw. 



1942 : see with irregular outer contact suggesting outer margin of 1945. 



1943: ilw well out in Iw and just under dw ; see with tliin dw and witii hint 

 of idw. 



1944 : Sv:ggestion of ilw ; see with thin dw. 



1945: Thin see with thin dw ; well-lignified psg in patches. (See fig. i, 

 pi. II, for detail.) 



