Page:Popular Science Monthly Volume 85.djvu/444

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440
THE POPULAR SCIENCE MONTHLY

method of inheritance differs in the case of normal and abnormal characters, but rather that abnormal characters are more striking, more easily followed from generation to generation, and consequently statististics are more complete with regard to them than in the case of normal characters. 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 partial list of these characters is given herewith:

 

Mendelian Inheritance in Man

normal characters

Dominant Recessive
Hair:
 Curly.  Straight.
 Dark.  Light to red.
 
Eye Color:
 Brown.  Blue.
Skin Color:
 Dark.  Light.
 Normal pigmentation.  Albinism.
Countenance:
 Hapsburg type (thick lower lip and prominent chin).  Normal.
 German type.  Jewish type.
Temperament:
 Nervous.  Phlegmatic.
Intellectual Capacity:
 Average.  Very great.
 Average.  Very small.

teratological and pathological characters
 
General Size:
 Achondroplasy (dwarfs with short stout limbs but with bodies and heads of normal size).  Normal.
Normal size.  True Dwarfs (with all parts of the body reduced in proportion).
Hands and Feet:
 Brachydactyly (short fingers and toes).  Normal.
 Syndactyly (webbed fingers and toes).  Normal.
 Polydactyly (supernumerary digits).  Normal.
Skin:
 Keratosis (thickening of epidermis).  Normal.
 Epidermolysis (excessive formation of blisters).  Normal.