Laws of Fluctuations 729 



disappear, and the line becomes smoother and 

 more uniformly curved. 



This method of arranging the figures directly 

 on a basal line is very convenient, whenever ob- 

 servations are made in the field or garden. 

 Very few instances need be recorded to obtain 

 an appreciation of the mean value, and to show 

 what may be expected from a continuance of 

 the test. The method is so simple and so 

 striking, and so wholly independent of any 

 mathematical development that it should be ap- 

 plied in all cases in which it is desired to ascer- 

 tain the average value of any organ, and the 

 measure of the attendant deviations. 



I cite an instance, secured by counting the 

 ray-florets on the flower-heads of the corn-mari- 

 gold or Chrysanthemum segetum. It was that, 

 by which I was enabled to select the plant, which 

 afterwards showed the first signs of a double 

 head. I noted them in this way : 



47 



47 52 



41 54 68 



44 50 62 75 



36 45 58 65 72 — 99 



Of course the figures might be replaced in 

 this work by equidistant dots or by lines, but 

 experience teaches that the chance of making 

 mistakes is noticeably lessened by writing down 



