212 



ROSCOE R. HYDE 



Control WJioxWHi 



T<} t. T f 



To K rs 



I^ *■ lo 



Cross 



HOi, 



'^m 



alfl]-- t^-'^o 



3-"^ 



Generation 



\H>"''- 



Diagram I Showing the ratio of males to females. Compiled from the 

 foregoing experiments. T = truncate; WH = Woods Hole; I = inbred. 



count for the rather large excess of females in these crosses. It 

 should be stated here as a matter of fact that the sex ratio does not 

 change with the age of the female.. Diagram I gives the sex-ratio 

 as compiled from the foregoing experiments. 



LITERATURE CITED 



CoRRENS, C. 1912 Selbsterilitiit and Individualstoffe. Festschrift der Medi- 



zin-Naturwissensch. Gessellschaft zur 84. Versammll. deutsch. Natur- 



forscher u. Arzte. Miinster i. W. Reprinted in Biologisches Central- 



blatt., Bd 33, No. 7, Juli, 1913. 

 East, E. M., and Hayes, H. K. 1912 Heterozygosis in evolution and in plant 



breeding. U. S. Department of Agriculture, Bureau of Plant Industry. 



Bull. No. 243. 

 Morgan, T. H. 1905 Some further experiments on self-fertilization in Ciona. 



Biol. Bull., vol. 8. 



1912 a A Modification of the sex-ratio, and of other ratios in Droso- 



phila through linkage. Zeitschrift fiir induktive Abstammungs. und 



Vererbungslehre, Bd. 7, Heft 5. 



1912 b The explanation of a new sex-ratio in Drosophila. Science, 



N.S., vol. 36, no. 934, November 22. 

 Shull, George H. 1911 Hybridization methods in co n breeding. American 



Breeders Association, vol. 6, p. 63. 



