Dominant and Recessive 



235 



will appear in this manner in the hybrid generation or be 

 dominant, to use Mendel's term, and which will disappear 

 or be recessive. 



Dominant and Recessive Characters in Man 



Dominant 



Curly hair 



Dark hair 



Beaded hair 



Hairiessness, associated with lack 



of teeth 

 White forelock 

 Brown eyes 

 Normal sight 

 Hereditary cataract 

 Normal hearing 

 Normal ear 

 Normal pigmentation 

 Hapsburg lip 

 Normal muscular tone 

 Nervous temperament 

 Supernumerary digits 

 Fused or webbed fingers or toes 

 Broad fingers (lacking one joint) 

 Fused joints of digits 

 Double- jointedness 

 Limb dwarfing 

 Normal growth 

 Immunity to poison ivy 



Recessive 



Straight hair 

 Light hair; red 

 Even hair 

 Normal condition 



Normal, even coloring 



Blue eyes 



Nightblindness 



Normal eye 



Deaf-mutism 



Otosclerosis 



Albinism 



Normal lip 



Low muscular tone 



Phlegmatic temperament 



Normal digits 



Normal, separate digits 



Normal number of joints 



Normal joints 



Normal condition 



Normal proportions 



General dwarfing 



Susceptibility to poison ivy 



The use of the word dominant in this connection must 

 not be confused with any other implications of the term. 

 There is no suggestion of greater potency, or greater impor- 

 tance. Among mammals, for example, pigmentation in the 

 hair is dominant over albinism; among certain strains of 

 poultry, however, whiteness is dominant over pigmentation. 

 Among rabbits short fur is dominant over long fur; among 

 cattle the absence of horns is dominant over the presence 

 of horns. 



