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THE AMEBIC AN NATURALIST 



[Vol. LII 



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Zyj%o£es:Phenotypic Ratio is -t 



I /f/ustrcttire Experiment:^ ^ 



Johannsen, W. Elements der Exakten Erblichkeitslehre, pp. 526-8, 191 

 Laughlin, H. H. The F, Blend Accompanied by Genie Purity. Ami 



Nat., pp. 741-751, 1915. 

 Shull, G. H. A Simple Chemical Device to Illustrate Mendelian Inher 



anee. Plant World, Vol. 12, pp. 145-153, 1909. 



Cold Spring Harbor H. H. LAUGHLIN. 



In a recent number of The American Naturalist 1 appeared a 

 paper by Ibsen and Steigleder on "Evidence for tbe Death in 

 Utero of the Homozygous Yellow Mouse." In summing up (p. 

 751), after stating that "our evidence tends to confirm the con- 

 elusion of Castle and Little that in mice homozygous yellow zy- 

 gotes are produced in the yellow X yellow mating, but that these 



1 Vol. LI, No. 612, December, 1917, pp. 740-752. 



