vi.] DATA. 81 



exactly the same weight ; those in K being the heaviest, 

 L the next heaviest, and so down to Q, which was the 

 lightest. The precise weights are given in Appendix C, 

 together with the corresponding diameters, which I 

 ascertained by laying 100 peas of the same weight in a 

 row. The weights run in an arithmetic series, having a 

 common average difference of 0*172 grain. I do not of 

 course profess to work to thousandths of a grain, though 

 I did work to somewhat less than one hundredth of a 

 grain ; therefore the third decimal place represents little 

 more than an arithmetical working value which has to be 

 regarded in multiplications, lest an error of sensible im- 

 portance should be introduced by its neglect. Curiously 

 enough, the diameters were found also to run approxi- 

 mately in an arithmetic series, owing, I suppose, to the 

 misshape and corrugations of the smaller seeds, which 

 gave them a larger diameter than if they had been 

 plumped out into spheres. All this is shown in the 

 Appendix, where it will be seen that I was justified 

 in sorting the seeds by the convenient method of the 

 balance and weights, and of accepting the weights as 

 directly proportional to the mean diameters. 



In each experiment, seven beds were prepared in 

 parallel rows ; each was 1\ feet wide and 5 feet 

 long. Ten holes of 1 inch deep were dibbled at equal 

 distances apart along each bed, and a single seed was 

 put into each hole. The beds were then bushed over to 

 keep off the birds. Minute instructions were given to 

 ensure uniformity, which I need not repeat here. The 

 end of all was that the seeds as they became ripe were 



G 



