110 Inheritance in the Cowpea 



is 312 : 14, i.e. 22-8 : 1*0. Further, the numbers obtained of each type 

 correspond closely with expectation on a ratio of 45 : 3 : 15 : 1. It seems 

 that the hypothesis that two Holstein factors might be involved in a 

 cross between Solid and Small eye holds good in this case without the 

 peculiar complications found in Cross 1. 



TheF,. 



The F.^ results are to be found in Table XI. The chief points worthy 

 of notice are as follows : 



1. Solid either bred true, segregated into S, W, H, and SE, segre- 

 gated into S and W, or segregated into S and H. 



The number of families of each of the above types was well in accord- 

 ance with the two factor hypothesis. 



Number of families 



It would seem that in the families which segregate into all four 

 types, occur the two types of ratio 45 : 3 : 15 : 1 and 9:3:3:1. As an 

 example of the latter ratio, may be given family No. 2 — 4 — 40, and of 

 the former ratio, family No. 2 — 11 — 20. 



2—4—40 

 2—11—20 



The two families which segregate into Solid and Watson are 

 apparently both of the 15:1 type. 



The Solids which segregated into Solid and Holstein did so in the 

 3 — 1 ratio. 



2. Watson should have exhibited two kinds of behaviour, (a) bred 

 true, (6) segregated into Watson and Small eye. Actually all the 5 

 Watsons segregated into Watson and Small eye in the 3 — 1 ratio. It 

 is somewhat remarkable that no pure Watsons were isolated. The 

 same point was noticed in regard to the Watsons of Cross 1. 



3. Holstein bred true or segregated into Holstein and Small eye. 

 Had a representative group of F2 Holsteins been taken for the F.^ 

 cultures the ratio of pure to heterozygous Holsteins should have been 

 7 to 8. Ten Holsteins were purposely selected showing the typical 



