ii6 Experimental Zoology 



of the other colors. The piebald character stands as a unit con- 

 trasted with uniform coat, but is independent of any particular 

 color. 



Data for Other Mammals and Man 



A few other cases in mammals, that seem to show discontinu- 

 ous inheritance, are known. Castle and Davenport have both 

 called attention to cases of so-called wonder-horses, i.e. horses 

 with remarkably long mane and tail. In the case of ''Linus I" 

 the mane was i8 feet long and the tail 21 feet. The parents 

 and grandparents of these horses also had unusually long hair, 

 which increased in successive generations. The data are insuffi- 

 cient to show the relation of dominance and recessiveness in this 

 case, but the persistence of the long hair seems to indicate its 

 dominance.* 



Harper and Hurst have recently examined certain data in 

 regard to the inheritance of coat color in horses. Harper deals 

 with the problem from the standpoint of prepotency of certain 

 colors in regard to ancestry, selection, age, and sex. Hurst shows 

 that bay and brown colors dominate completely chestnut, and 

 there are definite indications that these two colors follow Mendel's 

 law. 



Some statistics recently published (1904) by A. G. Bell have 

 furnished Davenport with material to study the relation of black 

 color to white color in sheep. The data show that when three 

 white individuals having as far as known white ancestors were 

 crossed with black sheep, the 13 lambs resulting {Fi) were white, 

 showing the dominance of white. Of 20 offspring from black 

 parents all were black.- When a black (recessive) individual 

 was mated with a dominant white (one of whose parents was 

 white and one black), 26 lambs were white and 25 black, which 

 is the Mendelian expectation. When a dominant-recessive 

 white was mated to a dominant-recessive white, 40 were white 

 and 7 were black. The expectation is 25 per cent black. The 



^ In guinea pigs the long hair is recessive. 



^ One uncertain case of white is given that is not above suspicion. 



