730 Fluctuations 



the figures themselves. Whenever decimals are 

 made use of it is obviously the best plan to keep 

 the figures themselves. For afterwards it often 

 becomes necessary to strike an average by a 

 somewhat different standard. 



Uniting the heads of the vertical rows of fig- 

 ures by a line, the form corresponding to Que- 

 telet's law is easily seen. In the main it is 

 always the same as the line shown by the meas- 

 urements of beans and seeds. It proves a dense 

 crowding of the single instances around the 

 average, and on both sides of the mass of the 

 observations, a few wide deviations. These be- 

 come more rare in proportion to the amount of 

 their divergency. On both sides of the average 

 the line begins by falling very rapidly, but then 

 bends slowly so as to assume a nearly horizon- 

 tal direction. It reaches the basal line only be- 

 yond the extreme instances. 



It is quite evident that all qualities, which 

 can be expressed by figures, may be treated in 

 this way. First of all the organs occurring in 

 varying numbers, as for instance the ray-florets 

 of composites, the rays of umbels, the blades of 

 pinnate and palmate leaves, the numbers of 

 veins, etc., are easily shown to comply with 

 the same general rule. Likewise the amount 

 of chemical substances can be expressed 

 in percentage numbers, as is done on a large 



