Sex-limited inheritance in Lychnis dioica L. 297 



If the female is a neutral homozygote, the B factor must be coupled 

 with F, just as if she were a positive homozygote, the only difference 

 in the formulae being that an M replaces the f in the formulae of the 

 males. The formulation on this basis appears as follows: 



XBF.XBF homozygous broad-leafed female, 

 XBF.XbF heterozygous broad-leafed female, 

 XBF.XbM broad-leafed male, 

 XhF.XbM narrow-leafed male. 



All three formulations fit the genetic facts and all can be with 

 equal propriety related to a chromosome explanation of sex. Something 

 more is needed before it can be decided that one of these formulae is 

 more likely to be a correct symbolization of the genotypic mechanism 

 of sex in Lychnis, than the others, and what is true of Lychnis in this 

 regard, is likewise true of sex-inheritance in most other species. 



A number of cases are now known in which genetic factors which 

 affect the same character, act in opposite directions, some producing or 

 intensifying a given character which others inhibit, diminish, or modify 

 in other ways. The same end-result may be produced by a retrogressive 

 variation from a more advanced condition, or by a progressive variation 

 from a less advanced condition. This being the case we are scarcely 

 warranted in assuming that such universally distributed differential 

 characters as femaleness and maleness are produced in all different 

 organisms by the same method, even though we can successfully apply 

 to all of them the same set of formulae. The fact seems to be that 

 the genotypic nucleus which is common to both the males and females 

 of any species, contains in itself nearly all of the elements necessary 

 to the production of both the male and the female of that species, and 

 it is therefore to a large degree essentially hermaphroditic. This is 

 evidenced by the general occurrence in each sex, of vestigial organs 

 which function only in the other sex. Under rare circumstances which 

 are largely or entirely unknown at present, some or all of these vestigial 

 organs may become more highly developed or even functional in an 

 individual. The statement often made that the male contains femaleness 

 and the female contains maleness is based upon such facts as these, 

 but the expression is not particularly appropriate, since it rests, not 

 upon what the two sexes possess, which is distinctive to each, but 

 upon that which they possess in common. There seems no good reason 

 for calling those things which both sexes possess in common, either 

 maleness or femaleness. It must be remembered only that w T hat they 



Induktive Abstammungs- und Vererbungslehre. XII. 21 



