June 11, 1909] 



SGIUNCE 



943 



allelomorphie pair that meet at 1 in sexual 

 ■anion, begin to blend at 2, present the picture 

 of a variable blend at 3, and fuse completely 



into a perfect blend at 4. A cross-section of 

 the diagram above line 3 represents the rela- 

 tive number of individuals of the different 

 kinds present at that time. The width of the 



diagram also indicates the amount of varia- 

 tion at any time. D = homozygous domi- 

 nants. B = homozygous recessives. DR = 

 heterozygotes. £' = a variable blend ever in- 

 creasing in number with each successive gen- 

 eration while D, B and DB decrease to dis- 

 appear entirely at 3. B' represents the con- 

 tinuation of the blend without either of the 

 originals of the allelomorphie pair, but with 

 all shades of intervening characters blending 

 in various ways as influenced by ancestry and 

 by environment, until a homozygote is formed 

 at 4. 



From 1 to 2 true Mendelism exists, spurious 

 Mendelism is found from 2 to 3, and from 

 3 to 4 no Mendelism is present but two tend- 

 encies prevail, (a.) the reversion to type, and 

 (h) the tendency to blend. 



The three Mendelian (?) conditions may 

 exist at the same time in a single individual, 

 one character exhibiting true Mendelism, 

 another false and a third no Mendelism, or 

 only one condition may be present at one 

 time. 



Davenport and Davenport* have established 

 true Mendelian heredity for eye color in man ; 

 Bateson* has designated many conditions in 

 man which indicate spurious Mendelism; and 

 Boas" has suggested the two hereditary 

 tendencies above mentioned, when broad- 

 headed and long-headed, or wide-faced and 

 long-faced individuals are united in marriage. 



My records of Negroes, of white students, 

 and of the Filipinos suggest that composite 

 types (elementary species?) of men when 

 crossed with opposite types follow the laws 

 of Mendel for not many generations, then 

 begin to blend, and eventually fulfill the re- 

 quirements of my scheme delineated above. 

 At present all mixed races are probably in a 

 condition of spurious Mendelism or no Men- 

 delism. Among the Negroes in America the 

 Hottentot is rarely seen, the Kaffir is often 

 encountered, and the Guinea Coast Negro is 

 abundant, but the majority of the Negro popu- 

 lation represents a variable blend of different 

 Negro types, and a large number of mixed 



= ScnsNCE, N. S., Vol. XXVI., 1908, p. 589. 



^ Brain, 1906. 



• American Anthropologist, 1903, 1907. 



