230 Maine Agricultural Experiment Station. 1918. 



bull and a dark Jersey dun-coated heifer were segregated out. 

 This is to be explained on the basis of a recessive dilutor in the 

 Guernsey, segregated out along with the black color. The dark 

 heifer shows that the Jersey does not normally possess this fac- 

 tor. 



It has been shown that white marking of the body taken 

 as a whole appears as a dominant. Study of the individual 

 white areas, however, indicate that this is due to white in the 

 inguinal region only, for this alone appears as such a domi- 

 nant. The white spots on the face (star, star snip, and blaze), 

 neck, shoulders, rump, flanks, and legs are, in general, sup- 

 pressed in their offspring when such animals are mated to solid 

 color. 



As has been suggested, but as has never been tested be- 

 fore, the pigmented muzzle is dominant to the one not so pig- 

 mented. 



Agreeing with the previous work of this laboratory it is 

 shown that a pigmented tongue is dominant to a non-pigmented 

 one. 



A black switch appears to cause the suppression of the 

 other switch colors in the offspring. Because of this suppres- 

 sion and because all of the matings had at least one animal 

 with a black switch as parent, it was impossible to study the 

 behavior of the other colors. There was one case of segrega- 

 tion of a deep red-orange switch from a back cross of a black 

 animal carrying an orange coat and white switch, genetically. 

 This case showed the segregation of the factor for orange 

 switch from that for both white and black. 



The character of polledness has been studied. Two-horned 

 animals resulting from crosses of polled x horned appeared. On 

 the basis of the other results these could not have resulted 

 from a heterozygous polled condition. One of these cases had 

 the horns tight on the head and the other loose. These cases 

 then form exceptions to the previously accepted hypothesis of 

 simple dominance for the polled character and require a sub- 

 sidiary hypothesis. The hypothesis suggested is that the testes 

 have some action on the presence or absence of horns. Partial 

 proof of this hypothesis is given by the fact that of the polled 

 animals 10 were females, 2 males, 1 doubtfully polled. Of 

 those with scurs 1 female and 7 males had loose scurs ; of those 



