220 Inheritmice in Dolichos lablab, L. 



The following characters have been studied in these experiments : 



1. Habit of growth. 



2. Anthocyanin colouration of flower, seed, and vegetative parts. 



1. Habit of Growth. 



The various races of Dolichos may be divided into two main groups, 

 according to whether the growth habit is indeterminate (climbing or 

 determinate, dwarf or bush). Emerson (1916) has described these two 

 types of growth habit in the French bean {Phaseolus vulgaris), and he 

 states that they also occur in the Lima bean (Phaseolus lunatus). The 

 determinate types are called bush beans from the fact that the main 

 axis terminates in an inflorescence after from 4 to 8 nodes have been 

 developed. The secondary branches which arise from the loAver nodes 

 also terminate in flower clusters. The indeterminate types are climbing 

 or pole beans. In these, an indefinite number of nodes is produced by 

 the main axis, termination of growth being due to unfavourable con- 

 ditions. Emerson (I.e.) records cases of the axis of a pole bean 

 terminating in a flower cluster. This condition has not been seen in 

 Dolichos. 



The Experimental Results. 

 Determinate x Indeterminate 



St Vincent Bush White Vilmorin's Stringless 



The ^1. The F^ consisted of two plants, both of which possessed the 

 indeterminate habit. 



The F^. The number of plants grown was 389. Of these 298 were 

 indeterminate and 91 determinate. The ratio of indeterminate to 

 determinate is close to the simple 3-1 ratio characteristic of a single 

 factor difference. The expected numbers are 292 indeterminate and 97 

 determinate. 



The F3. Seventeen families were grown from F^ indeterminates; 

 Four families bred true to indeterminate, consisting altogether of 271 

 plants. Thirteen families segregated into indeterminate and determinate 

 in the 3-1 ratio. Of 635 plants, 478 were indeterminate and 157 

 determinate, with expectation 476 and 159 respectively. 



Ten families were grown from F^ determinates. All these families 

 bred true, — containing altogether 325 plants. 



The ^4. Twenty-eight families were grown. These were derived 

 from families which bred true to the determinate habit in F3. These 

 twenty-eight families, containing altogether 829 plants, continued to 

 breed true in F.. 



