ange in mm. 
Dia. chi 
Temperature °F. 
458 BOTANICAL GAZETTE [JUNE 
temperature of the soil at a depth of 12 inches is also shown in 
the same figure for comparative purposes. No direct correlation 
between the march of diameter growth and current temperatures 
was found. A careful study of the graphs leads to the inference 
26 ONEOEG 
MOGUL LUGUECAQUGLERELUAUGGOER CEEOL REGGE SO TSU CETTE ORR 
26 TTT MMR UUHAE 7 AMET PRUE FanuuaereUrUM ML 
22 CT MUMUBERTT TTT TAL aA, APOC MMM eo WATTAGE ua 
32 COT 1 a OEE VAN AGMA ME 
RT TT at ahd EE EC 
is HUUTTTEULUTGEREUAMEEEAEE nant nnn ianatt iggeormomerempeenermrrmatig 
Pe PO ther ctrl HA IONONIN 
Fg VUGVUNUENUUOURUOUINAORNOTONONS zt MRL DAILY MARCH OF DIAME i Ht 
DTT] CHANGE IN| BLUE apes TRUNK HAUL TEOEL i 
08 
os HHT 
04 
02 
MUUHULEREELUS UHL ative me itl 4 
Tin at aL WUT HLH “nie MN SERAPSER ULE a MR wt 
Tr ITER MANET XNA Ee i 
HUNT LICRLLIT cA UAV ARETE IHOPUEULVONBRUOSVvcO2%0 800 TEE 2S UMNR OA (2S 
TENA Ud NL I VMUMAUE SEER AGERE i MMMUEG Waki OC UL ATAVUS 
THINAYNI EY MLE IMUURTTTEGHEEE CONT FEE ETO ALT 
mn SUAAHT Ode24c4aZesC00UQ000QQQEUGSQQUAUSELUSEOUUUUESITESTEGOOUIVESOOIANNUADLE ATTRA Lt ee 
aoe 
== 
2. 
poe SUUGNRGMO Oc AQGHNSORRUOONUUVUTNNGEROCGOOULEGOOOOEVEGUEUROUGQOOOUHOOLONOQOUOUOOU 20 URREE OGG Gah VOOOE, SOLER HBC i. 
22 MEAN DALY 7 a a 
Me \] 
6 OMT OF AV AT DEPTH OF 12, LALA aE 
HUUUUURU ANTON OUONR POG, UU) 400 00ERR (EET 
COA TTHITITIEtttt Ha HN EERE inte 
HUAUEORODGUUGURAUROO RRO ROULORE AND. CORTICAL LA LA AYER 
HUUUUEREGG UNG OGUEOURGRUIORE fC ortioal Layer 
nee Mr 
TMT ——— HNNNUUAHUUHGEELUOB ULE ante 
36 TTT mutt ce SOUL HLLSULELLEL eT 
pee VUNUALOUUNLEQON UEOOUTONUEIONE MECC CT GEE HET 
- AE TT 
ah 
Fic. 3.—Daily march of diameter change in blue spruce trunk, daily mean 
temperature of air, soil at depth of 12 inches, and cortical layer adjacent to cambium; 
Big Cottonwood Canyon, 25 miles southeast of Salt Lake City, Utah, June 8- 
October 6, 1920. 
that the growth response lags behind the temperature, a marked 
drop in the temperature causing a decrease in or even a cessation 
of growth’. Harrie (4), as a result of extensive investigations, 
advanced the theory that the awakening of cambial activity was 
ince writing the preceding, an interesting temperature pomp was 
es on a blue spruce tree growing on the writer’s lawn in Ogden, Ut = 
May 12, 1921, the buds on the north side of the tree had swollen and were just 
beginning to open, while on the south side practically all buds were open and new 
growth of 3-5 cm. had taken place on the tips of the branches. This difference in 
the inception of growth is believed to be a to the higher temperatures to which 
the buds on the south side of the tree were subjected. 
