REPRODUCTION 109 



supposed to stop the flow of milk when desired. The 

 Russian woman of the Caspian Sea only needs to 

 turn the nutshell filled with quicksilver on to her 

 back instead of on her breast to cause her milk to 

 cease. In another place the mother who wishes to 

 discontinue suckling must let some of her milk drop 

 into the fire. Mother's milk is often used as a medi- 

 cine. The application or partaking of such milk is said 

 to be capable of curing fevers, deafness, whooping- 

 cough, and many other ailments. 



Finally, we should mention the fact that a woman 

 may bear more than one child at the same time. 

 This is called multiple pregnancy. Twins occur 

 about one in eighty cases of normal birth; triplets 

 perhaps one in six thousand cases. Even more 

 than three children at a birth have sometimes been 

 observed. This is, of course, harking back to the 

 animal type, in which litters of young generally con- 

 sist of any number from two to six and even more. 

 Twins may arise from two different causes. There may 

 be two ova in the uterus and each be fertilized by a 

 separate sperm, in which case the twins may both 

 be of the same sex or of different sexes; or one pro- 

 perly fertilized ovum may split up into two, each 

 forming a complete embryo, in which case, it is said, 

 both embryos will always be of the same sex. 



The birth of twins is received with horror by some 

 races; the children are often killed or exposed. In 

 the Caroline Islands one of the children is given away 

 to a brother or near relative of the father, for the 

 islanders believe that otherwise the child would die. 

 In Suaheli they used to kill twins, but now they give 

 them to^the^missions, as they do crippled children. 



