24 



Journal of Agricultural Research 



Vol. XV. No. I 



sive dilution factor for this fawn. The proof for this factor being reces- 

 sive comes in the fact that the F^ cross was a back cross of a black Guern- 

 sey V'l bull on a Guenrsey cow. Furthermore, this factor from the 

 nature of the cross can not be sex-linked as in the case of Wentworth's 

 explanation of the dark shade of brown in the coat of the male Ayr- 

 shire (46). 



The case of the almost identical appearance of the dark dun F2 heifer 

 and her Jersey parent agrees well with the findings of Kuhlman (17) 

 for Jersey X Aberdeen-Angus crosses. These cases support the con- 

 clusion that in the Jerseys any such dilution factor as that m the Guern- 

 sey is not normally present. 



General White Markings of the Coat 



Most investigators have considered that white markings found in the 

 different parts of the coat were due to a piebald factor exhibiting great 

 somatic variation (19, 21, 43, 48). This statement of the case seems to 

 the author to have many contradictions, but as this appears to be the 

 popular belief the data will be treated first from this point of view. 

 Table VIII presents this treatment. 



Table VIII. — Behavior of the general white markings in the parental and first filial 



generations 



Sire. 



Description of mating. 



Offspring. 



Taurus Creamelle Henger- 

 veld. 



Do 



Kay an 



Do 



Lakeland's Poet 



Do 



Minor crosses: 



Crossbred o 



Spotted X solid color. 



Spotted X spotted 



Spotted X solid color. . . . 



Spotted X spotted 



Solid color X solid color . 

 Solid color X spotted . . . . 



Do. 



Crossbred 10 



Lady Primrose's Governor 



of the Fountain. 

 Delva 's University De Kol . , 

 Johanna Lad Manor De Kol 

 Columbia's Fox 



Fi spotted carrying' solid 

 color X solid color. 



Fi spotted carr)'ing solid 

 color X Fi spotted carry- 

 ing solid color. 



Fi spotted X spotted 



Spotted X spotted 



.do. 



Spotted X solid color. 

 ....do 



2 solid colors, 5 spotted. 



8 spotted , I solid color. 



3 solid color, 3 spotted. 

 3 solid color, 13 spotted. 



1 solid color. 



2 solid color, 3 spotted. 



2 solid color. 



3 spotted. 



I solid color. 

 Do. 



I spotted. 

 Do. 

 Do. 



Two points of importance come out in consideration of these data: 

 First, the white piebald factor must be dominant; second, this factor 

 must be present in the bulls in the heterozygous form, as each bull 

 throws some solid-color animals. The first conclusion is not strange, 

 for it is to be expected that the factor is dominant, recessive, or perhaps in- 

 termediate in its efifect. The fact could, however, be just as well explained 

 by the presence of a dominant factor for white in a given part of the 



