LUTHER BURBANK 



Another hybridizing experiment with the beans, 

 also undertaken in the early day of my investiga- 

 tions, 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 diflflcult to make this 

 cross, but after many fruitless efforts I at last suc- 

 ceeded in securing a single pod containing four 

 sound beans by using the pollen of the lima on the 

 pistil of the horticultural bean. 



"When these beans were planted, in the summer 

 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 specimens) were indubi- 

 tably those of the lima bean; while the lower part 

 of each cotyledon was precisely that of the horti- 

 cultural pole-bean. 



These parts were connected with serrated 

 edges, which at last separated, allowing the lima 

 bean part to drop away. Such separation, how- 

 ever, did not occur until the vines had made a 

 foot or more of growth. 



[102] 



