No. 585] INHERITANCE OF HABIT 



551 



Type c probably represents the varieties which early 

 send up a few shoots high in the air like Burpee String- 

 less. In such beans the growth of the main stems or 

 branches is not entirely prevented by the absence of 

 the character which produces a long axis, and as the 

 climbing habit is more or less developed, the characteris- 

 tic shoots are sent up. 



Type d represents the semi-runners, caused by the 

 short axis. 



Combinations of type e and e 2 are the spreading varie- 

 ties, with long outstretched branches. They are to be 

 distinguished from runners by terminal inflorescences. 

 Kenny Rustless is a representative of the e type of habit 

 and probably Prolific Black Wax also. 



The last two combinations, / and /,, are the typical 

 erect bush form, such as Blue Pod Butter and Challenge 

 Black Wax. 



Table II gives the possible crosses of these types and 

 the F 2 proportions to be expected when the forms crossed 

 are the most nearly typical. In the cases of typical 

 forms, the F 2 types should be differentiated without 

 much difficulty. A circumstance that must be looked 

 upon as a possible cause of exceptions is the presence of 

 unknown factors that cause variations in the intensity of 

 the development of the twining habit and of the inter- 

 mediate lengths between long and short axis. If there 



the case in all quantitative characters (3), and if the 

 twining habit is to be explained in much the same way, 

 results may be considerably at variance with the expecta- 

 tions indicated in Table II. It must be remembered that 

 the constitutions given for the varieties are only as- 

 sumed. 



At present, owing to circumstances mentioned before, 



TABLE II 



