TOTEMISM AND EXOGAMY 233 



who are the children of a brother and a sister re- 

 spectively is not excluded. Yet neither of these 

 unions is permitted by custom working outside 

 the class-system ; the former union is punished 

 by death, and, as regards the latter, such cousins 

 may not shake hands with one another or give 

 presents to one another or even mention one 

 another's names, and they may only converse with 

 one another at a distance of some paces (ii., 130). 

 It is possible that a similar idea explains the avoid- 

 ance of the mother-in-law so common amongst 

 primitive races, and of which an extreme case is 

 mentioned from the Bank's Islands, where a man 

 will not even walk along the beach after his mother- 

 in-law until the rising tide has washed away the 

 footprints which she had left behind her (ii., 76). 

 It would seem as if, though the class-system per- 

 mitted such a marriage, a better feeling rose up 

 to declare it impossible. 



It has already been mentioned that there are 

 cases, as amongst the Arunta, where marriage 

 with a person of the same totem is not forbidden, 

 but this exception must be dealt with later on. 

 The other is the general rule, namely, the custom 

 that persons of the same totem may not marry 

 together. 



We have now to turn to the consideration of 

 various general questions as to the origin of these 

 strange customs, and here, needless to say, we 

 embark on the sea of theory, leaving behind us the 

 dry land of fact which we have hitherto been 

 treading. 



What gave rise to the idea of totems ? That is 



