Little: Coat Color in Pointer Dogs 



247 



that they have not the abiHty to produce 

 blacks when mated inter se; while the 

 formation of yellows in liver by liver 

 matings shows that liver animals may 

 possess the factor E in half or all their 

 gametes. 



Types 3 and 4 — Yellow. The dis- 

 tinctness of these two types of yellow 

 is seen by the following matings : 



Female 40471 yellow was crossed 

 with male 47940 liver. It is known from 

 the 97 matings of liver-colored animals 

 that no liver-colored animal can carry 

 the factor for black. If this mating 

 produced any black young, therefore, 

 it would be certain that it was the 

 yellow parent; in this case female 40741 

 that carried the factor for black. The 

 actual result was seven brown, five 

 yellow, and six black young. The yellow 

 parent was accordingly of the formula 

 Be. 



The other type of yellow is seen in a 

 mating between female 46990 yellow 

 and male 54357 brown, which gave only 

 brown (liver) young, eight in number. 

 Here the yellow parent was of the for- 

 mula be. 



In the case of certain animals it is 

 possible to form a more or less definite 

 idea of their gametic constitution. Thus, 

 for example, male 41525, black, is 

 undoubtedly BbEe in formula. When 

 crossed with females of formula bbEE 

 (homozygous liver), he has sired 10 

 black and 16 liver-colored puppies, the 

 Mendelian expectation being equal num- 

 bers of these two colors. When crossed 

 with yellow females he has sired four 

 yellow and six non-yellow young, equal- 

 ity being again expected. When crossed 

 with liver-colored females heterozygous 

 in E (formula bbEe), he has sired eight 

 blacks, two browns and three yellows. 

 In this case a 9:3:4 ratio is expected. 



Another famous sire, 40708 black, 

 is probably of the formula BbEE. Thus, 

 when crossed with brown females, he 

 has sired 1 7 black and nine brown young ; 

 13 black to 13 brown being the theoret- 

 ical proportions. When crossed with a 

 yellow female he has given a total of 

 seven young, all non-yellow in character. 



IMPORTANT PRACTICAL POINTS. 



Several points of importance to the 

 practical breeder now became apparent. 



In order to purify a strain from black 

 individuals it is only necessary to go on 

 breeding liver to liver and yellow to 

 yellow indefinitely. As long as this is 

 carefully done there should be no 

 blacks produced. Yellows from two 

 liver parents may safely be crossed with 

 liver-colored animals. If, however, any 

 other yellows are used, the breeder may 

 expect a certain number of black young 

 among the progeny. To obtain a pure 

 black strain is not so simple, requiring 

 for its certain completion a separate 

 breeding test tor each black individual 

 by crossing it with yellows coming from 

 two liver parents. If among the progeny 

 any liver or yellow young are found, it is 

 certain that the black in question is 

 not of the formula BBEE, and will, 

 therefore, not breed true. Among the 

 liver animals there should theoretically 

 be found two types; one homozygous 

 for the factor E and one heterozygous 

 for this factor. The former type should 

 in crosses with yellows produce only 

 non-yellow young. To this class belong 

 the following liver animals, 54357, 

 52793 and 47456, which have produced 

 by yellow mates, eight, six and five 

 liver-colored young respectively. The 

 other type of liver animal carrying 

 yellow as a recessive, is seen in such 

 animals as 44135 and 41348. These 

 animals when mated to yellows have 

 produced a total of three liver and two 

 yellow young, the Mendelian expecta- 

 tion being equal numbers. 



Before considering the data in this 

 paper as conclusive, breeding experi- 

 ments should be made. The writer 

 believes, however, that the data is 

 worthy of pubhcation, since it hints 

 strongly that the methods of color 

 breeding, used so successfully in the 

 case of the smaller mammals, may be 

 of value in breeding dogs. It also shows 

 that the stud books of the American 

 Kennel Club may be used as a source 

 of information as to color inheritance 

 in the case of several breeds of dogs. 

 In addition it shows tentatively that 

 there is a recessive type of yellow dog, 

 analogous to the recessive yellow of 

 guinea-pigs; and that the relation of 

 brown to black is the same in dogs as in the 

 other small mammals in which the matter 

 has been experimentally investigated. 



