.316 



The Journal of Heredity 



TWO TWIN-BEARING FAMILIES 



Figure 10. Males are denoted by squares, females by circles. • Double symbols indicate 



twins. The last pair of twins in the Bush family are the two boys shown in the Frontispiece. 



All the pairs are monosexual twins in both families, but some of the pairs in the "W" family 



.are known not to be identical. These charts do not tell much about the manner of inheritance 



of twinning, but they do indicate that the character is hereditary in some families, at least. 



nearly all appear to be of the similar 

 type. Another point we found was 

 that as they approach each other in 

 appearance almost, not quite uniform- 

 ly, they express increasing" fondness 

 for each other. It could be imagined 

 that if, through the inbreeding and 

 assortative mating, husl)ands and wives 

 should ever become as nearly alike in 

 make-up as some of these twins are, 

 that the divorce courts would be 

 forced out of business. One twin, 

 ^evidently highly educated, writes of 



herself and her brother, "reared 

 under exactly same environment, but 

 we have never agreed on anything. I 

 love school work and he hates it. 

 He dislikes everything I am fond of, 

 although we get along well together." 

 Two brothers, obviously unlike in ap- 

 pearance, write : "One is fond of out- 

 door life, and the other enjoys books 

 and indoor study." Twins seem to 

 have their drawbacks. One mother 

 writes, "I am getting tired of having 

 to drop my work and go to the other 



