550 



THE AMERICAN NATURALIST 



[Vol. XLIX 



scribed as having long tendril-like shoots above the plant, 

 another along side of this had shorter shoots, perhaps 

 AIT. Among the lots, all degrees of climbing were devel- 

 oped; one plant encountered was evidently aLT like the 

 one mentioned in a previously discussed cross; plants 

 with more or less outstretched branches were noted. 

 Type notes on F x and F 2 generations of an earlier cross 

 in type ; F 2 segregates into 25 bush forms and 62 runners, 

 are significant. The F 1 generation is described as pole 

 probably including pole beans of the F x type. The ratio 

 is disturbed by the lack of a clear understanding of the 

 true basis for classification of plant type in beans. The 

 F 2 of another cross involving the same varieties is noted 

 as having 41 bush and 5 runner beans. 



White Marrow and Burpee Kidney yielded two lots of 

 bush beans and two heterozygote lots giving 6 plants with 

 terminal inflorescence and 15 with axillary. 



Eed Valentine and White Marrow crosses give similar 

 results. In an early cross, the F 2 generation plants have 

 been grouped according to the general plant type, no at- 

 tempt being made to separate intergrading types. The 

 notes give the results of segregations as 75 bush and 136 

 runner beans. Later generation heterozygotes approach 

 a proportion of 9 runner to 7 bush beans. The apparent 

 behavior probably depends on whether the intermediate 

 types are classed as runner or bush. In the cross in 

 which only the F 4 generation was observed, only constant 

 bush types seem to have been isolated. 



Cross Type 19 or 21. AIT X alt or alT 

 Blue Pod crossed with Burpee is a representative cross 

 of this type. Only in a few cases was the Burpee type, 

 plants with shoots high in the air, observed, as most lots 

 isolated were homozygous and erect. In the F 2 genera- 

 tion of an early cross, plants described as runners ap- 

 peared. The proportion was 3 runners to 1 bush. Heter- 

 ozygote lots descended from these plants segregated in 

 the same manner, totaled 18 bush and 71 so-called run- 



