112 Inheritance in the Cowpea 



3. Holstein Large eye spotted proved to be invariably heterozygous. 

 Some of the Holsteins were obviously of the XhH : \^E type, but 

 families of the SH.lSE type— e.g. No. 5—5—20 (52 : 18) were also 

 present. In many families the number of plants is too small to decide 

 which type of ratio prevails. /Pwo of the families apparently segregated 

 into Large eye spotted and Small eye. In these families classification 

 was difficult and some of the plants were referred first to the Large eye 

 spotted form and then to the Saddle. 



4. Holstein Saddle proved to be homozygous. There was great 

 variation in the extent to which the pattern was developed on the seed 

 coat, but it was not possible to effect an accurate classification of the 

 differences. It may be possible to distinguish by external appearance, 

 the different Holstein combinations, but this would need a more careful 

 examination than the present writer has been able to give. 



It will be noticed that a few of the families threw an occasional 

 Solid. This is probably due to accidental crossing by the carpcntei* bee, 

 Xylocopa sp., and the set of results can scarcely be discarded on this 

 account, though due care should be exercised in weighing the whole 

 mass of evidence. 



Since Holstein Large eye spotted is always heterozygous and Holstein 

 Saddle homozygous, it is interesting to go back to the F2 results and 

 consider them anew. In the Fo of this cross there were altogether 

 116 Holsteins. Of these 10 were not classified further. Taking the 

 rest, 52 were Large eye spotted, and 54 were of the Saddle form. On 

 the two H factor theory the ratio of pure to heterozygous Holsteins 

 is 7:8, and the ratio actually obtained 7*6 : 7*4 (54 : 52). Thus the 

 evidence from the behaviour of F.^ Holsteins in F. is strongly in favour 

 of the two H factor hypothesis. 



Summary of Results of Investigation on Pattern of the Seed Goat. 



In two crosses involving Red Solid and Small eye it has been shown 

 that three independently inherited factors are concerned. These are : 



W — The factor for the Watson pattern. 



Hi — A factor for the Holstein pattern. 



Hg — A second factor for the Holstein pattern, having the same 

 effect as Hj. A combination of W and either of the Holstein factors 

 produces the Solid type of pattern, while absence of all three factors 

 produces the Small eye pattern. 



