150 LUTHER BURBANK 



investigations, brought together two varieties 

 that are even more distantly related. 



Crossing Pole Beans and Limas 



In this experiment I hybridized the horticul- 

 tural pole bean, or "wren's egg" with the lima 

 bean. It proved exceedingly difficult to make 

 this cross, but after many fruitless efforts I at 

 last succeeded in securing a single pod con- 

 taining four sound beans by using the pollen 

 of the lima on the pistil of the horticultural 

 bean. 



When these seeds were planted, in the sum- 

 mer of 1872, a very strange result was observed 

 — the beans themselves had in all respects the 

 form, size, and appearance of the horticultural 

 bean, but when their sprouts broke ground it 

 was at once observed that the upper part of 

 their cotyledons (varying from one-quarter to 

 three-quarters of their length in different speci- 

 mens) were indubitably those of the lima bean; 

 while the lower part of each cotyledon was pre- 

 cisely that of the horticultural pole bean. 



These parts were connected with serrated 

 edges, which at last separated, allowing the lima 

 bean part to drop away. Such separation, how- 

 fever, did not occur until the vines had made a 

 foot or more of growth. 



