INHERITANCE IN MANKIND 45 



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— a scheme which shows at once the effect of marriage 

 between two persons, each of whom, though not 

 openly affected, has the peculiarity as a germinal 

 character. 



As long as an individual contains only a single dose 

 of the factor, the peculiarity, being recessive, does not 

 become manifest. But, as soon as two persons who 

 possess the concealed character marry, one-quarter of 

 their offspring may be expected to be impregnated with 

 a double dose, and to be pure recessives with the 

 peculiarity apparent. If such persons intermarried, all 

 their offspring would be affected, and a definite breed, 

 showing the peculiarity, might be established. 



It is clear that a recessive character is much more 

 difficult to trace through a pedigree than is a dominant 

 character. As a clue for research it may be pointed 

 out that peculiarities which are prevalent among the 

 offspring of consanguineous marriages, especially those 

 between first cousins, are likely to prove recessive 

 factors. If the pecuHarity be concealed in the blood 

 of a family, when cousins marry, it is probable that 

 some of their children will get the recessive character 



