HEREDITY 301 



neighbouring beds ; all the seeds in their pods are 

 of the same size, that is to say, there is no little pea 

 at the end as in the pod of the common pea, and 

 they are very hardy and prolific. I procured a large 

 number of seeds from the same bin, and selected 

 seven weights, calling them K (the largest), L, M, N, 

 O, P, and Q (the smallest), forming an arithmetic 

 series. Curiously, their lengths, found by measuring 

 ten of a kind in a row, also formed an arithmetic 

 series, owing, I suppose, to the larger and plumper 

 seeds being more spherical and therefore taking less 

 room for their weight than the others. Ten peas of 

 each of these seven descriptions, seventy in all, formed 

 what I called a "set." 



I persuaded friends living in various parts of the 

 country, each to plant a set for me. The uniform 

 method to be followed was to prepare seven parallel 

 beds, each i^ feet wide and 5 feet long, to 

 dibble ten holes in each at equal distances apart, 

 and i inch in depth, and to put one seed in each 

 hole. The beds were then to be bushed over to 

 keep off the birds. As the seeds became ripe they 

 were to be gathered and put into bags which I sent, 

 lettered respectively from K to Q ; the same letters 

 having been stuck at both ends of the beds. Finally, 

 when the crop was coming to an end, the whole 

 foliage of each row was to be torn up, tied together, 

 and sent to me. All this was done, and further 

 minute instructions, which I need not describe here, 

 were attended to carefully. The result clearly proved 

 Regression ; the mean Filial deviation was only one- 

 third that of the parental one, and the experiments 

 all concurred. The formula that expresses the 



