82 BIOLOGY AND SOCIAL PROBLEMS 



ever increasing dilution. Nevertheless it is this 

 extremely minute amount of material in the 

 egg cell that gives rise to that which deter- 

 mines in the adult. 



The fullness of this determining power is 

 seldom appreciated for the reason that, in or- 

 dinary births, we have nothing as a standard 

 whereby to judge of the looseness or rigidity 

 of the process of inheritance. But in identical 

 twins, triplets, and so forth, one individual in 

 each group may be taken as a standard for the 

 rest in the group, and we can judge from the 

 similarity of the members in a single group 

 how closely the process works. Wilder gives 

 us good evidence on this point taken from a 

 set of identical triplet girls by a person who 

 was familiar with them. This person described 

 them in the following terms : " I have seen 

 twins that looked very much alike, but I could 

 see a difference when they were together. I 

 could not see any difference in these triplets 

 when they stood in a row before me, and I 

 never saw any one else who could, except their 

 mother. She said she could, but I doubted it ; 

 they used to fool her often. When they were 

 babies she kept different colored beads around 

 their necks to tell them by. They always 



