THE fact that jealousy is very closely related to the popular conception of the role of sex indicates that the whole subject needs clarification. The meaning and implication given to fidelity and possession often disturbs the human fellowship of husband and wife and brings to a head the personal problems threatening understanding and harmony. Not only does jealousy express the competition between man and woman, man and man, and woman and woman; it intensifies the competition. Because investigation of this subject offers so many opportunities to explore the bases of many conflicts in marriage, as well as the differences between their logical and psychological content, it is profitable to use this topic as the beginning of aD. analysis of concrete problems.