Sex-limitt'il inht'i-itani'p in Iti/rhius iliiiicn L. 299 



strongly sui)ports my conrliisinii MkiI the li(u-iiKiplirodite tmitants resulted 

 from ;i modificatiou in the mah' genotyi«'. A further proof of this re- 

 lation between the hermaphrodites and males is given by the occurrence 

 of a narrow-leafed herma|)hrodite mutant in a family which included narrow- 

 leafed males, but in which no nai'row-leafed females were due to appear. 



One well developed hei-maphroditic specimen, when used as the 

 polleii-]iarent in three different crosses, produced a progeny of 276 females 

 and no males nor hermaphrodites. It is suggested that this plant may 

 have l)een a "somatic" herma,i)hrodite whose genotypic constitution was 

 that of a normal female. 



Suggestions are made for the slandarilizatioii of genetic formulae 

 and a list of 50 formulae which have been used to represent the geno- 

 typic interi'elatious of the sexes, are arranged under the six standard 

 formulae which represent the various conceptions which may be logically 

 related to current Mendelian methods of inter])retation. 



There are two natural divisions of the sex-formulae, in one of 

 which the female is a sex-homozygote, in the other a sex-heterozygote. 

 Under each of these there are three available sets of formulae which 

 differ from each other according as an individual of the homozygous sex 

 is represented as a positive, a negative, or a neutral, homozygote. In most 

 cases there is no basis for other than a imrely arbitrary choice among 

 these fdi-muhu', since they all fit ('([ually well the genetic facts and can 

 be related in most cases with e(pial ease to the cytological observations. 



Males do not possess femaleness, nor do females exhibit maleness, 

 but what they both possess in common is nearly all of what they each 

 are. For this reason it is not difficult to believe that the actual 

 realization of the one or the other sex may rest upon relatively minor 

 circumstances which may be totally different in different cases. 



Literature cited. 



Arkei,!,, T. R., 1912: Further report on inlieritaiico of horn ami wool roveriiig in shppp, 

 Ann. Rep. Amer. Breeders Ass. 8: 501^568. 



Arkell, T. R., and Davenport, C. B., 1912: Horns in shcop as a typical sex limited 

 character. Science N. S. 35: H75 — .377. 



Bateson, W., 1909: Mendel's principles of heredity, pp. 396. Cambridge: The Uni- 

 versity Press. 



Bateson, W., and Punnett, R. ('., 1911: The inheritance of the peculiar pigmentation 

 of the silky fowl. Jour. Genet. 1: 185— 20;i. 



Baiir, E., 1911: T'^inflihrung in die experimentelle Vererbungslehre, pp. 29H. Berlin: 

 Gebrüder Borntraeger. 



