288 Colour and Markings in Pedigree Hereford Cattle 



we have seen that some pure recessives are not so white as others, but 

 so far all individuals bearing too much white that have been studied 

 have given identical results when bred from. 



II. Extension of the Pigment or " Dark Neck." 



PI. VII, figs. 4 and 5 and Plate VIII, grades 4- 2 and + 3 show the 

 type of colouring referred to as "dark-necked"; this kind of pigmen- 

 tation is apparently nearly but not quite completely dominant to the 

 ordinary white-necked description of marking. 



In the case of a cow called Shelsley Cypress, that was dark- 

 necked, only two out of six calves, all by normally marked bulls, 

 have shown any white on the neck. Presumably the cow is a pure 

 dominant for the character, the sires being heterozygous, but dominance 

 not being always complete^ white shows in some of the heterozygous 

 offspring. The following pedigree will make this clear. That one of 



? «? 



Cypress x General Buller (20648) 

 (Vol. 38, p. 350) normal 



Cameron x Shelsley Cypress x Bounds Chance (29544) 



(28152) 

 normal 



9 



(Vol. 41, p. 307) 

 Dark neck 

 DD 



normal 

 DNW 



More than three-quarters 

 of his produce very dark 



Albynes 

 Champion 



(Vol. 50) 



Dark 

 DD or DN 



Diagram 2. Pedigree showing the Inheritance of the " Dark Neck " character. 

 D indicates the factor for the pigmentation of top of the neck, etc. 

 N indicates the factor for normal colouration, and 

 W is for excessive white. 



the completely dark-necked calves was a pure dominant is shown by the 

 fact that when subsequently used in a herd of non-pedigree general 

 utility Herefords this young bull sired practically all dark calves. 

 I have unfortunately not been able to obtain the exact figures relating 

 to his produce, but his present owner, a very careful and accurate man, 



^ Further on in this paper it will be shown that the factor for excessive white has an 

 inhibiting or neutralising effect on that for "dark neck," so that these calves may have 

 been heterozygous for too much white. 



