American Journal of Botany. 
Volume I, Plate XVII. 
Rate of 
of * H J 
mm. in ^ 
growth 
1 A T 'in 
\% hour's 

1 
Vl 1 
\ 
— 
1 
/ 
~^ 
\ 
Temp. 35 40 45 50 55 60 65 70 75 80 85 90 95 100 IIO°Fahr. 
Fig. I. 
MacDougal: Climatic Complexes, 
