No. 536] 



COLOR INHERITANCE 



40!) 



the experimental breeders with lower mamnials. It may, 

 of course, be found that all mammalian albinos have the 

 white pigment (melanin) described by Spiegler for 

 white horses. Such a result would seem to correlate a 

 number of apparently discordant facts. It would obvi- 

 ate the further assumption of an "antioxidase" sug- 

 gested by Grortner, and render more intelligible the non- 

 recessive behavior of human albinism. 3 No theory of 

 color-inheritance is satisfactory that can not embrace all 

 the facts of albinism, and such is the present state of 



In crosses between whites and negroes there is gener- 

 ally a partial dominance of the deeper pigmented condi- 

 tion over the lighter in the second (mulatto) generation; 

 the third generation showing a measure of segregation 

 of the original colors. The partiality and incomplete- 

 ness of dominance and segregation may be due to a 

 "myriad" other factors modifying and obscuring more 

 or less the final results. 4 



Seeing that we are dealing with only one kind of col- 

 ored granules, the apparent segregation noted in the 

 families of mulatto parents does not here seem to be due 

 to a condition of unstable equilibrium in the chemical 

 constitutions of the parental melanin and an attempt at 

 readjustment to an original state of greater stability, as 

 suggested by Riddle. 



The apparent continuity of the melanogenetic process, 

 as seen in the continuous numerical irradation of the 

 same colored pigment granules where a graded series of 



