Decreased Fertility in Female Mice Immunized With a Carrier Followed by Small Numbers of Spermatozoa

It has been conclusively shown that immunization of female mice with spermatozoa can significantly decrease their fertility (McLaren, 1964, 1966; Edwards, 1964; Bell, 1969; Bell & McLaren, 1970). All of the work by McLaren and Bell (McLaren, 1964, 1966; Bell, 1969; Bell & McLaren, 1970) has involved very extensive courses of immunization: from twenty-one to twenty-four injections of 6 to 15 × 106 spermatozoa or fractions thereof. Edwards (1964) used shorter and more varied immunization schedules, with three to eleven booster injections in different individuals of one experimental group, and found a smaller effect on the number of eggs fertilized than McLaren and Bell found on the number of liveborn offspring (McLaren, 1964, 1966; Bell, 1969; Bell & McLaren, 1970). However, none of the female mice in Edwards experiments received fewer than