604 Journal of Agricultural Research vol. xx, No. s 



SUMMARY 



Syndactylism in swine is allelomorphic and dominant to normal 

 cloven-foot, and black is allelomorphic and dominant to red. The two 

 pairs of factors are evidently independent of each other. 



The factor for syndactylism does not show quite the same effect on 

 the front feet as on the hind feet, for the fusion is usually less complete 

 in the latter. 



The Duroc-Jersey and mule-foot are both self-colored in this cross 

 and transmit no distinct spotting factors. We have concluded tenta- 

 tively that the hybrids between Duroc-Jersey and Berkshire (or Poland 

 China) are spotted because the latter transmit highly selected dominant 

 spotting factors. 



Intensity of red appears to be due to the interaction of independent 

 factors which do not affect black. Dilution of red or yellow to cream or 

 white takes place when either one or neither of the interacting factors 

 is present. The so-called white hair of some breeds like the Berkshire 

 and Poland China is really a very dilute red of genetic composition 

 similar to our cream segregates. 



LITERATURE CITED 



(i) Dabrowa-Szremowicz, S. v. 



1905. eine neue abart vox schweinen. In Illus. Landw. Ztg., Jahrg. 

 25. No. 63, p. 564. 4%. 



(2) 



1905. Einhuferschweine. In Illus. Landw. Ztg., Jahrg. 25, No. 92, p., 

 8io-8ii, 3 fig. 



(3) Davenport, Charles B. 



1909. INHERITANCE OF CHARACTERISTICS IN DOMESTIC FOWL. IOO p., 12 Col. 



pi. Washington, D. C. (Carnegie Inst. Washington Pub. 121.) 

 Literature cited, p. 99-100. 



(4) Kronacher, Carl. 



1912. GRUNDZUGE DER ZUCHTUNGSBIOLOGIE . . . Xvi, 323 p., 95 fig., 9C0I. pi. 



Berlin. 



(5) Lewis, Thomas. 



1908. ADDENDUM TO MEMOIR: " SPLIT-HAND AND SPLIT-FOOT DEFORMITIES." 



In Biometrika, v. 6, pt. 1, p. 117-118. 



(6) and Embleton, Dennis. 



1908. SPLIT-HAND AND SPLIT-FOOT DEFORMITIES, THEIR TYPES, ORIGIN, AND 



Transmission. In Biometrika, v. 6, pt. 1, p. 26-58, 3 fig., pi. 1-7. 

 Bibliography, p. 56-58. 



(7) Pearson, Karl. 



1908. ON THE INHERITANCE OF THE DEFORMITY KNOWN AS SPLIT-FOOT OR 



lobster-claw. In Biometrika, v. 6. pt. 1, p. 69-79, pi- 8-16. 



(8) Severson, B. O. 



1917. color inheritance in swine. In Jour. Heredity, v. 8, no. 8, p. 



379-3 81 . 1 n g- 



(9) Spillman, W. J. 



1910. history and pecularities of The mule-Foot hog. In Amer. Breed- 



ers' Mag., v. 1, no. 3, p. 178-182, illus. 

 (10) Wright, Sewall. 



1918. color inheritance in mammals, viii. swine . . . In Jour. Heredity, 



v. 9, no. 1, p. 33-38. 



