Multiplication of Extremes 753 



of the variety, and only the partial fluctuability, 

 due to the effect of later influences, can now be 

 studied statistically. 



This study has for its main object the pro- 

 duction of sugar in the stems, and the curves, 

 which indicate the percentage of this important 

 substance in different stems of the same variety, 

 comply with Quetelet's law. Each variety has 

 its own average, and around this the data of the 

 majority of the stems are densely crowded, 

 while deviations on both sides are rare and be- 

 come the rarer the wider they are. The ' * Cher- 

 ibon '' cane is the richest variety cultivated in 

 Java, and has an average of 19^ sugar, while it 

 fluctuates between life and 28^. '' Chunnic '' 

 averages 14^, '' Black Manilla'' 13f and "White 

 Manilla ' ' 10^ ; their highest and lowest extremes 

 diverge in the same manner, being for the last 

 named variety If and 15^. 



This partial variability is of high practical 

 interest, because on it a selection may be found- 

 ed. According to the conceptions described in 

 a previous lecture, fluctuating variability is the 

 result of those outward factors that determine 

 the strength of development of the plant or the 

 organ. The inconstancy of the degree of sensi- 

 bility, combined with the ever-varying weather- 

 conditions preclude any close proportionality, 

 but apart from this difficulty there is, in the 



