74 Physico-Chemical Properties of Vegetable Saps [March, 



The ranges in mean molecular weight of the solutes for the 

 several experiments are : 



Experiment Wall Prolification 



A 87.9 — 117.0 = 29.1 86.9 — 1197 = 32.8 



B 108.4 — 146.1 == 37-7 1044 — 130.2 = 25.8 



C 108.1 — 123.6=15-5 112.8 — 125.3 = 12.5 



D 114.0—127.3 = 13.3 115.8 — 126.6=10.8 



E 111.9 — 138.0 = 26.1 114-7 — 145-7 = 31-0 



The differences in the ranges are quite striking. For both ovary 

 wall and abnormal carpellary mass, exp. C and D show a far nar- 

 rower ränge of Variation than the other three series, notwithstand- 

 ing the f act that exp. A and B, which show on the whole the widest 

 ranges, comprise but a few determinations.^" 



For the three large series the Standard deviations and coefficients 

 of Variation are : 



Coefficient 

 Series Standard deviation of Variation 



c 



Wall 4.000 + 0.510 3-423 



Prolification 4.718 + 0.601 4-Oi7 



D 



Wall 3-434 ±0.473 2.855 



Prolification 3-125 + 0.430 2.571 



E 



Wall 7-561 ± 0.850 6.118 



Prolification 8.371 + 0.941 6.649 



Thus, the Variation in the mean molecular weight in exp. E, as 

 measured by the Standard deviation or coefficient of Variation, is 

 distinctly higher than that of the two other large series, just as it 

 appeared to be when measured by the ränge of Variation. The 

 explanation of this greater variability in certain of the collections 

 is probably the same as that suggested for the observed differences 

 in other constants — that of environmental heterogeneity and of dif- 

 ferences in the physiological State of the individual at the time the 

 samples were taken. 



10 The significance of this fact must be obvious after a moment's consid- 

 eration. If differences in constants were to be attributed to faulty technique, 

 one would expect to find the greatest differences in the largest series, for there 

 would be more opportunities for errors leading to widely divergent constants. 



