136 LUTHER BURBANK 



each year, and by using the entire product for 

 the seed in successive years, the progeny of the 

 single vine from which I developed the new 

 variety had been multiplied by 1912 so that 

 material enough was at last in hand to plant 

 hundreds of acres and supply the cannery with 

 the small, sweet, uniform-sized and uniform- 

 ripening pea that was desired. 



I have cited this case in detail, not because it 

 is of exceptional importance in comparison with 

 hundreds of others of my plant developing ex- 

 periments, but simply because it illustrates the 

 possibility of developing quite rapidly a par- 

 ticular plant to meet a specific commercial need. 



But to understand fully the conditions met 

 even in this single experiment, it is necessary tq 

 add that I did not confine attention to the pro- 

 duction of the single variety just described, even 

 in the line of experiments that were undertaken 

 specifically for the purpose of producing that 

 variety. On the contrary, while scrutinizing the 

 vines for small peas of uniform size, I kept 

 vigilant watch also for other vines that varied 

 in the opposite direction. 



Peas Modified in Other Directions 



By carrying forward several series of selec- 

 tions at the same time, a number of varieties 



