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THE AMEBIC AN NATURALIST [Vol. XLIV 



"white melanin" seems also to suggest that the two 

 whites are due to the presence and absence of melanin. 

 He states : 



It is readily understandable that white horse hair can not be without 

 pigment. We know pigmentless hair, i. e., albinos, these have appar- 

 ently the natural color of the keratin ( llornrohstoffs) from which the 

 hair is formed, modified by a special morphological condition. These 

 questions need a more searching study. We must now determine 



hair. It is in this manner that we can finally decide whether the color 

 of gray hair is due, as we have previously supposed, to disappearance 

 of pigment and air content or rather to the change of the darker pig- 

 It is in this condition that the study was left. Inasmuch 

 as this question is of the utmost importance from the 

 standpoint of heredity, the work of melanin investiga- 

 tion has been taken up in this laboratory. 



In a study of SpieglerV paper the most noteworthy 

 detail which appears to be wanting is a comparison be- 

 tween the percentage of black pigment in the black wool 

 or hair and the percentage of "white melanin" found in 

 the white varieties. S] >iegler gives the method of isolation 

 as practically the same for both varieties, but does not 

 mention the yields of melanin obtained. He, then, gives 

 his analytical data leading to an empiric formula of 

 C 50 H 5S N s SO 12 calculated to ash-free (ash = 9.8 per cent.) 

 melanin from black horse hair and C 4B H 78 N 10 SO 20 calcu- 

 lated to ash-free (ash = 16.28 per cent.) "white mela- 

 nin" from white horse hair. 7 He further states: 



The black pigment body with the simplest formula of C^H^SO,, 

 and the light pigment body of C, r ,H 7s X, SO :o differ, as the analytical 



they are identical in nucleus (" im Kerne "), and that the different color 

 is due to the entrance of a chromatic group. Very apparent is the 

 great difference in hydrogen content. The white pigment contains 

 much more hydrogen, oxygen and even nitrogen, while the carbon-poor 



