1909] CURRENT LITERATURE 469 



female and gynomonoecious plants, and therefore the difference in weight which 

 was assumed by Darwin to be a secondary sexual character has no such signifi- 

 cance. 



Correns has also investigated 4 the percentage of female and hermaphrodite 

 plants in Plantago lanceolata under conditions of controlled pollination, and has 

 shown that while this plant, like Satureia and Silene, shows a marked tendency 

 for each sex to reproduce its own kind, nevertheless there is considerable variation 

 in this regard in individuals of both sexes. By pollinating the same female indi- 



rma 



hermaphrodites 



tion of hermaphrodite offspring and of females is so related in each case that they 

 may be readily calculated, after once the strength of the hermaphrodite tendency 

 in the pollen-parent and of the female tendency in the pistil-parent is known. 

 In other words, each individual appears to have a different strength of these two 

 sex-tendencies and to produce germ-cells of two kinds w T ith respect to these tenden- 



rm 



portional to the strength of the sex-tendencies in the parents. 



rm 



in their tendency to produce a certain sex, but that they are definitely either female 

 or hermaphrodite, puts these plants into the class known as ever-sporting varieties, 



recogniz 



difficult type of inheritance. 



2jerm-cell is definitely female or hermaphrodite 



and that the female is dominant allowed the prediction of the actual numbers 

 of each sex produced in the different experiments with a fair degree of accuracy. 



Several other papers have recently appeared dealing with the question of 

 sex-determination. Doncaster and Rayxor 5 found that in crosses between 

 Abraxas grossulariata, a common English moth, and its rare variety laciicolor, 

 reciprocal crosses are not equal, for when a laciicolor female is crossed with a 

 grossulariata male, no laciicolor offspring are produced, and males and females 

 are all grossulariata; but when the reciprocal cross is made, all of the females 

 are laciicolor and all of the males grossulariata. To explain this strange situation 

 the authors assumed that sex is a Mendelian character, and that the laciicolor 

 character is coupled with the female determinant. It was assumed that both 

 male and female individuals are heterozygous with respect to sex. In this regard 

 their interpretation differed fundamentally from that of Correns, who assumed 

 that in the case of Bryonia alba X dioica and other dioecious plants the female 

 sex is homozygous, and the male heterozygous. 



Bateson and Punnett, 6 in discussing Doncaster's results, show that a 



CORREN 



mung der gynodioecischen Pflanzen. Ber. Deutsch. Bot. Gesells. 26a: 686-701. 1908 



5 Proc. Zool. Soc. 1:125. pi. 1. 1906- 



6 Science N. S. 27:785. 1908. 



