MELANIN COLOR FORMATION. 339 



form on the northern hills. There exists, to be sure, a relation 

 between the vapors and the heaps of snow, between the egg and 

 the definitive character but the one is not the other, does not 

 contain the other. 



In accounting for melanin color characters, I would maintain 

 that -- granted the continuance of other life and developmental 

 processes we can account for all the major happenings of color 

 development and inheritance with extremely little of assumption. 

 It is knoivn that one oxidase is concerned. I think we need 

 make use of but one. It is knoivn that the germ possesses 

 actively the power to oxidize amino acids. I think we need 

 make use of nothing in the germ than just this power. It is 

 known that the protoplasm of different species, of different tissues, 

 of different parts of a cell, possess different powers of oxidizing 

 protein bodies. It is no tremendous assumption that germ cells 

 are not freaks of nature in this respect, and that they too have 

 different powers of tyrosin oxidation. The fate of color charac- 

 ters then is bound up (i) in the union of these particular powers 

 of the two germ cells ; (2) in the origin (through other outside 

 developmental processess) of favorable and unfavorable regions 

 for tyrosin oxidations ; and (3) in environmental conditions. 



Let us now for a moment return to the matter of color-blends. 

 The data given furnish a nearer view practically a new concep- 

 tion of the nature of color-blends in inheritance ; if the position 

 stated in regard to these color-blends is correct a little thought 

 will convince that at the same time new light is furnished on alter- 

 native color inheritance ; and particularly on what is happening 

 in the case of the so-called alternative (Mendelian) inheritance of 

 a color character. It can be said definitely in such a cross that 

 it is the pcnver to oxidize tyrosin compounds (a power which I be- 

 lieve, by no stretch of imagination, needs to be, or can be, repre- 

 sented by a particle in the germ, but by a general property of 

 the protoplasm of germ cells and of tissue cells) that is transmitted 

 and that here this power of one of the gametes is continued into * 



1 Tyrosinase has recently been found in the eggs of cephalopods by Weindl ('07). 

 Similarly, several enzymes have been isolated from germ cells in recent years ; in 

 none of these cases can we for a moment suppose that these enzymes or zymogens 

 existed as a particle in any one, or in each, of the chromosomes. I would, however, 

 by no means have it inferred that I consider the presence, quantity, etc., of tyrosinase 



