40 



BULLETIN 700, V. S. DEPAETMEISrT OF AGRICULTUEE. 



data given for each station represent slightly different numbers of 

 days. In figure 19, as well as in certain other graphs, the curves are 

 comparable in each case as to direction of slope; but it should be 



/5 



/s 



14 



13 



IZ 



10 



IS 26 



K 





\ 









\ 





\ 



J/32 











\ 



idaa.z 



\ 



\ 



■^330 





r- _ 



\ 





"^ 3932 



^^-^ 



-.^ 



Xj 







\ 



N 



^ 



665 



3zas 





\ 

 \ 



/oes.a^ 











^"-.^ 

















"V^ 









^v 



466 J 











81 L 



hys 



10 I 



Days 





65 L 



>ays 



Oak-Brush Type 



Aspen- Fir 



Spr 



-Fir 



Temperafure Above 40° F 



Sum Of Daily Means 



Physio/oaical Temperafure Efficiency 



Fig. 20. — Temperature efficiency summations for period of growth of special experiments. 



understood that the lengths of the ordinates- are not in all cases di- 

 rectly comparable ; the vertical scales employed are merely convenient 

 ones and are quite arbitrary. 



