108 Inheritance in the Coivpea 



Examining the F-^ families in the light of this hypothesis the matter 

 can be set forth as follows : 



{a) The Solids. 



Obtained ... 12 10 



From these results it is evident that so far as the F.^ families are 

 concerned the hypothesis is well confirmed that two Holstein factors 

 are involved in this cross. 



The two H factor hypothesis leads to further important consequences. 

 These are : 



(a) 4 Solids out of 45 should give in i^g a ratio of lbS:lW. 



(6) 4 Holsteins out of 15 should give in F.^ a ratio of \bH : \SE. 



A study of the F.^ families which show segregation into 8 and W 

 does not lead to the belief that the 15 : 1 ratio occurs. The number of 

 fomilies is small. Some of the segregating F^ Holsteins may possibly 

 show the 15 : 1 ratio, e.g. 1-10—7 (31 : 3), and 1—10—16 (16 : 1) but 

 again the number of plants grown is too few to determine this point 

 with certainty. 



(c) Out of the 18 families which segregate into all four types in 

 F-i, 50 per cent, are expected to show the 9:3:3:1, and 50 per cent, 

 the 45 : 3 : 15 : 1 ratio. With such small numbers it is scarcely possible 

 to get more than an approximate idea of whether both types of ratio 

 occur, but taking the families as they stand we have : 



Family No. 1—10—26. 



8 W H SE 



Obtained 40 1 8 1 



Calculated ... 35-1 2-3 11*7 0-8 



Family No. 1—6^—9. 



S W H SE 



Obtained 66 5 19 1 



Calculated ... 63-9 4-3 18*3 1-4 



on 45 : 3 : 15 : 1 basis. 



