Vol. 7, 1921 
PHYSIOLOGY: H. S. REED 
315 
= .0242(* - 47.4) 
#2 = deviations of from x. The root-mean-square deviation of Xi from 
x is 2. 38 cm., and that of x 2 from x is 3. 14. 
Finally, a growth process which closely coincided with values computed 
from the usual formula, may be mentioned. In the paper cited (Reed, 
1920) the average height of a population of young walnut trees (/. regia) 
was presented. The calculated values had a root-mean-square devia- 
tion from the observed of only 3.12 cm. The equation for growth as 
derived by graphic method was 
log 153^7 = ' ° 208( ' " 96)1 '° 3 - 
