HOWARD, HOWARD AND ABDUR RAHMAN 



203 



of crossed plants as regards flower colour was made in 40 of these cultures in 

 each of which there was an average of sixty plants. Thirty cultures bad only 

 one stray plant each, seven had two plants, two had three plants and one bad 

 four plants — altogether 54 heterozygotes as regards flower colour among 

 2,400 plants, or 2*25 per cent. Through an oversight, similai counts as regards 

 seed characters were not carried out. Grown in single lines next to next, the 

 percentage of natural crossing is much larger. In an actual case it was found 

 to be (as regards flower colour only) 578 in a total of 4,838 plants, or 12 per 

 cent. 



The characters which best lend themselves to the detection of hetero- 

 zygotes and which show the kind of splitting which takes place in this crop 

 are the general colour and markings of the standard, the colour of the pod and 

 the characters of the seed coat. A number of careful observations have been 

 made on these matters which are worthy of record. 



As regards splitting in the general colour of the flower and in the markings 

 of the back of the standard, the following three cases may be quoted : — 



1. A parent plant with orange flowers (the back of the standard with 

 many red lines and a diffused reddish colour) gave rise the next year to 64 

 plants which were grouped as follows (Plate II) : — 



Back of the standard 



(a) Flowers pale yellow. 



Without lines 

 With a few red lines 

 With red lines 

 With many red lines 



Plants 

 2 



4 

 2 

 2 



(6) Flowers deep yelloiv. 



Back of the standard 



rWithout lines 



I With a few red lines 



'-With many red lines 



(c) Flowers orange. 



Back of the standard 



'Without lines .. .. 9 

 With red lines .. ..13 

 With many red lines . . . . 12 

 With many red lines and more dif- 

 fused red colour , , , , 8 



