332 THE AMERICAN NATURALIST [Vol. XL VI 



they do, a person with a little practise will make very 

 few mistakes; (c) even if errors are made, the treatment 

 is the same for all series. 



All the pods counted had at least one matured seed. 

 This specification is necessary since, especially in the 

 autumn, some plants produce quite a number of half de- 

 veloped and completely sterile pods. If these were in- 

 cluded there would be no point where a line could be 



O JO 20 30 40 SO 10 20 30 40 



drawn between the number of flowers and the number 

 of pods produced by an individual. 



The record forms do not interest the general reader. 



The original data are given in Tables A-C. The phys- 

 ical constants appear in Tables I-III. 



The extreme sensitiveness of the number of pods per 

 plant to environmental conditions is seen at once from an 



