Sentence:  The special relation between men and their totems is shown by a belief which exists in a large number of tribes, to the effect that the men have the power to make their own totem animal or plant increase in numbers; so that a kangaroo man can cause the kangaroos to multiply, a <WSD>rain man</WSD> can make rain, and so on. A kangaroo man cannot make rain,  nor can a <WSD>rain man</WSD> do anything to increase the number of kangaroos. 
Meaning of the word marked with <WSD> tags:  A man who is believed to have power to control the rain.