t5B HaJfhoariness hi Matthiola 



Conclusion. 



The results recorded here and in the earlier work form a concordant 

 body of facts concerning surface character which the scheme of factor 

 relations here suggested enables us to bring together into a compre- 

 hensible whole. These factor relations involve five factors — C, R. H, J, K 

 -^inter-acting as three distinct pairs. 



(1) The pair OR essential to the production of sap colour. 



(2) The pair HK producing the fully hoary condition but only 

 effective when the VR pair is also present. 



(3) The pair JK which produces a less degree of hairiness than 

 HK. For this reason the presence of J can only be detected in the 

 absence of H. The effect of the combination J and K is to produce 

 the condition known as half-hoary if the individual has the constitution 

 JJKK or JjKk, i.e. if the dose of the two factors is equal. If K 

 has been brought in on both sides of the pedigree and J only on one, 

 i.e. if the individual has the constitution JjKK, the result is to dilute 

 the effect of/, and the individual exhibits the lesser degree of hairiness 

 known as quarter-hoary. It remains to determine the appearance of 

 the individual in the reverse case when the constitution is JJKk, and 

 also to ascertain whether the effect of ./ is independent of G and R or 

 whether, like H, it is only effective when the colour pair is also present. 



The expenses incurred in connection with this work have been 

 defrayed in part by grants from the Royal Society and from the British 

 Association for the Advancement of Science. 



