POLYDACTYLISM IN CATTLE' 



Elmer Roberts 



Agricultural Experiment Station, Urbana, Illinois 



THE inheritance of extra digits or 

 polydactylism has been studied in 

 poultry, guinea-pigs and man. Its 

 occurrence in cattle has been known for 

 a long time and man\' cases have Ijeen 

 recorded. Through the kindness of Dr. 

 C. B. Olney who called my attention 

 to its presence in a herd of dairy cattle 

 owned by Mr. Paul Peglow, Prairie 

 View, Illinois, an opportunity was 

 afff)rded to note the inheritance of this 

 character in cattle. 



A normal bull mated toapolydactyl- 

 oiis cow ha\ing three toes on each foot 

 pnxluced a female showing the same 

 condition. Information concerning 



other offspring was not available. This 

 latter female mated to a normal, un- 



related bull has produced three male 

 calves all of which were polydactylous. 

 Two of these were like the mother 

 having three toes on each foot, while 

 the third had three toes on each front 

 foot, four on one hind foot and fi\e on 

 the other. In the hind legs of this 

 third calf there was said to be a dupli- 

 cation of the normal number of bones 

 between the hock and the hoof, that is 

 of the metatarsals. 



Figure 28 illustrates graphically the 

 inheritance of this character. Figures 26, 

 29 and 30 show the expression of the 

 polydactylouscondition in thedam of the 

 three calves. Figure 25 is of the normal 

 foot in cattle. It should be noted that 

 the extra toes on front feet are much 



COW'S NORMAL FOOT 



POLYDACTYLOUS FOOT 



Polyclartylism is the possession, by man or animals, of nu)rf than the normal niimln'r of (iigits. 

 The case descrihecl here is another proof of the inheritance of this abnormality. The polydactylous 

 foot shown at the right al)OVC is a close view of the ri^hl hind foot of the cow pictured on the 

 opposite page. (Figs. 25 anfl 26.) 



' Paper .\o. l.S from the Laboratory of Genetics, Illinois .\gricultiiral Kxperiment Station. 



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