n6 



Heredity and Environment 



B A 



FIG. 39. X-RAY PICTURE, A OF A NORMAL, B OF A SHORT-FINGERED 

 (br achy dactyl) hand. (From Bateson.) 



normal characters are more striking, more easily followed from 

 generation to generation, and consequently statistics are more 

 complete with regard to them than in the case of normal char- 

 acters. In many cases statistics are not sufficiently complete to 

 determine with certainty whether the character in question is 

 dominant or recessive, and it must be understood that in some 

 instances the classification in this respect is tentative. A par- 

 tial list of these characters is given herewith: 



MENDELIAN INHERITANCE IN MAN 



NORMAL CHARACTERS 

 Dominant Recessive 



Hair: 



Curly 



Dark 

 Eye Color; 



Brown 

 Skin Color: 



Dark 



Normal Pigmentation 



Straight 

 Light to red 



Blue 



Light 



Albinism (Fig. 37) 



