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THE AMERICAN NATURALIST [Vol. XLVIII 



17,216 families like (16), 

 65,536 (=16 X 4,096). 



Sixth Generation 

 Constitution of the Population.— 



786,A32AA + 262,lUAa + 262,144aA + 786,432aa. 



Proportion of Homozygotes in This Generation. — 75 per cent, 

 of the whole population. 



From this point on it will not be necessary to carry out the 

 work in detail. The final results are given in Table I for four 

 more generations. 



3,407,872 



4,395,264 44,040,192 

 3.724.5 41,052 570,425,344 570,425,344 

 in 01.W7.50UKM; 7.:iM.!»75.M40 7.SS1. 



It is evident that the proportion of homozygotes is approaching 

 100 per cent, in the same manner as in the case of self-fertiliza- 

 tion, worked out by East, Jennings and others, but at a slower 



In a later paper I hope to take up the problem of the general 

 formulae for finding the constitution of a Mendelian population 

 after n generations of inbreeding of the different types, and at 

 the same time discuss the relation of these results to the coeffi- 

 cients of inbreeding described in my former paper. It should be 

 specifically mentioned that, in the light of the data here set forth, 

 those criticisms of the conclusions of East and Hayes made in my 

 former paper 1 which were based on the erroneous assumption of 

 a fundamental difference between self-fertilization and all other 

 forms of inbreeding in respect to homozygosis, have no validity 

 whatever. It scarcely needs to be said that the blunder on the 

 theoretical side here corrected in no wise affects the usefulness of 

 inbreeding coefficients. Kaymond Pearl 



s Cf. Pearl, loc. ext., p. 606, 609 and 610. 



