xn] Human Stature 209 



signs of a segregation more complete than exists among 

 mulattos* 1 . 



Mr Mudge has published also reports of the existence of 

 segregation in regard to several characteristics in the cross- 

 bred offspring of Canadian Red Indians and Europeans 

 (Nature, Nov. 7, 1907). 



Pending further research we must take it that the 

 mulatto is probably a genuine exception, in so far at least 

 as no obvious segregation normally occurs. 



Respecting the genetics of other normal characteristics 

 in man, such as stature, little progress has been made. The 

 case of human stature is interesting as it furnished material 

 for Galton's original determination t of the Law of Ancestral 

 Heredity spoken of above (p. 6). We may feel assured 

 that this deduction is to be interpreted as meaning that the 

 number of factors involved in deciding human stature is 

 large which indeed is evident, if it be remembered how 

 many kinds of physiological difference must contribute to 

 the determination of the length of the body. Something 

 must be decided by the number of cells in the leg-bones, 

 vertebrae and various cartilages, by the size of these cells, 

 by the amount and density of the bony substance secreted, 

 by the shape of the skull, by the obliquity of the neck of the 

 femur, by the curvature of the spine, and by many elements 

 of bodily proportions, some easily influenced by conditions, 

 which interact with each other to produce the single 

 "character" we call height. Such a character could only 

 show segregation if it were studied in families made by the 

 inter-crossing of extreme forms each breeding sensibly true 

 to type. It is perhaps a little remarkable that in the pea 

 and the sweet pea segregation in height should be so 

 marked, but the reason is evidently to be found partly in 

 the immense differences there available for study, and in 

 the existence of one predominant contributing factor, the 

 internodal length. 



* There is a good deal of scattered information which tends to show 

 that even among negro-mulattos segregation sometimes occurs. See, for 

 instance, W. Lawrence, Lectures on PhysioL, 1823, p. 259. 



t Natural Inheritance^ 1889. 



B. II. I4 



