14 Heredity and Child Culture 



traits seen in the offspring. As there are nu- 

 merous possible and diverse combinations of 

 these ancestral germ units, we can understand 

 how varying may be the characteristics of 

 different individuals. Numberless combina- 

 tions may be possible as it has been estimated 

 that there are 48 chromosomes in the sex cells 

 of the white woman. It is further supposed 

 that variation may be caused by a recombi- 

 nation of these ancestral germ units in future 

 generations, as well as by changes that may 

 take place in the germ plasm itself. Pro- 

 longed undernourishment and various poisons 

 may ultimately have a disastrous effect upon 

 the germ plasm. It is not supposed, however, 

 that changes in the body plasm or soma can 

 have direct effect on the germ plasm. 



One of the most interesting theories concern- 

 ing the method of action of heredity is known as 

 Mendelism, a term taken from the name of Gre- 

 gor Mendel by whom it was first elaborated. 

 According to this theory, the unit characters in 

 the sex cells do not blend but remain distinct 

 and are thus passed along at birth. These 



