142 Journal of Agricultural Research voi. vi. No. 4 



yellow in the female, but it is recessive in the male. Something lethal 

 seems to be connected with homozygosis for white; hence, white as a 

 somatic character appears only in the female. The yellow female is YY, 

 the white female YW. Males are either YY or YW, but are always yellow. 

 Jacobson (3) made some observations on Papilio mennon L., which 

 were studied from a Mendelian standpoint by De Meijere (5) in 1910. 

 There are three varieties of females in this species known as Achates, 

 Agenor, and Laomedon, respectively, in the order of their dominance. 

 The males corresponding to these three forms are all alike, although 

 each of the female patterns may be carried in a recessive manner. Fur- 

 thermore, De Meijere believes that the female carries the male pattern 

 homozygously ; but, owing to the reversal of dominance, the male 

 character never becomes somatic. The I^aomedon probably represents 

 the female expression of the male condition. The principal difference 

 between this and the previous cases is that the changes in dominance 

 affect the homozygotes as well as the heterozygotes. 



AYRSHIRE BLACK-AND-WHITE 



A case which seems to fall under this genera^, sex-limited group is found 

 in the inheritance of black-and-white as alternative to red-and-white in 

 Ayrshire cattle. While the general breed color is red-and-white, black- 

 and-white animals have been known for some time, as shown by Kuhl- 

 man (4). Practically no attention has been paid to the mode of inherit- 

 ance of this color, since in America it has been considered undesirable 

 and selection against it has been practiced. It is difficult to state 

 whether the black is due to a true black pigment or whether it is simply 

 a very dense red. Under the microscope typically black granules seem 

 to be present, but no chemical solutions of the pigments have yet been 

 attempted. 



SOURCE OF THE DATA ^ 



The Ayrshire herd bull at the Kansas Experiment Station, Melrose 

 Good Gift, is a very deep mahogany-and-white ; in fact, the black-and- 

 white previously referred to. It is through the study of his ancestry 

 and breeding performance, the ancestry and breeding performances of 

 the cows in the herd, including the black-and-white animals, and the 

 records of some of the former herd bulls that the present data were secured. 

 In all, 63 individuals were included. Much larger numbers might have 

 been obtained by adding the progeny of red-and-white males and females 

 to the table; but since they demonstrated no facts different from those 

 here included, their records are not presented. 



* Acknowledgments are hereby niade to Prof. O. E. Reed, of the Department of Dairy Husbandry, 

 Kansas Experiment Station, for facilities extended in obtaining the data. 



