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THE AMERICAN NATURALIST [Vol. XLIV 



formation are present. Davenport 17 has already put 

 forward a view very similar to the above and it is hoped 

 that in the near future this laboratory will have sufficient 

 data to test this hypothesis. 



Summary 



1. Dominant and recessive whites in the Mendelian 

 sense, have no relation to the presence of Speigler's 

 ' ' white melanin. ' ' 



2. The "white melanin" was found to be present in 

 all forms of keratin structure which were studied, but 

 in very small amounts as compared with true melanin 

 from black wool. 



3. In view of the small percentage of "white melanin" 

 found, Spiegler's view that it is an "oxidized black" 

 seems impossible ; neither is this view upheld by a study 

 of Spiegler's work. 



4. It seems highly probable that Spiegler's "white 

 melanin" bears no relation to true melanins, but is a de- 

 composition product of the keratin. 



5. A theory is advanced that dominant whites are due 

 to the presence of an anti-oxydase which prevents pig- 

 ment formation; recessive whites, on the other hand, 

 have neither power to form pigments nor to inhibit the 

 formation. 



"Davenport, Beport Am. Breeders' Assoc., 5, 382, 1909. 



