HEREDITY. 1 1 



such an inactivity, we see that the process to be influenced did 

 not take place, that the developmental stage acted upon, was 

 not passed by the individual. Throughout this book, we use the 

 term Gene, as a neutral one, as proposed by Johannsen, for 

 these inherited things. Genes can be factors in the develop- 

 ment, inherited factors. All inherited factors are genes, but 

 all the genes present in a germ, need not be factors in the devel- 

 opment. A certain number of the genes will be transmitted 

 regularly, while only occasionally, or not all, participating in the 

 development of the individual. It is fundamentally wrong to 

 use the term "Factor" for the genes, because it necessitates the 

 assumption of an occasional latency. The presence, or absence 

 of a certain gene, may determine a definite difference in the 

 final qualities, but is inadmissable to speak of such a gene as of 

 the "determiner" for that quality. All the other genes contribut- 

 ing to the developmental process which results in the charac- 

 ter in question, could each and all in their turn be called its 

 determiner. The use of the term "Unit-character" should, we 

 think, be discontinued. The characters of an organism are not 

 so many separate, separable things, they are all the result of 

 the interaction of a great many factors, some inherited, genes, 

 and some constituting the environment. There is no reason for 

 the assumption, that occasionaly genes are present in a zygote 

 in a state, which insures their inactivity. In so far as the coop- 

 eration or non-cooperation of a given gene to the development 

 of an individual is determined in the zygote, is it determined 

 by the combination of other genes present. It is clear, that this 

 conception of "latency" of characters is fundamentally differ- 

 ent from that of de Vries. We have every reason to believe 

 now, that every gene is present in the zygote in the same state, 

 that every zygote is a fresh beginning, that, in as far 

 as an individual's character can be said to be determined in 

 its germ, they are given in the combination of genes present 

 not in peculiar states of some of them. An organism's qualities, 

 characters, are the result of its development, as such they can 

 not be said to be inherited. Its genes are inherited from its 



