Iron was administered by intramuscular injection to female rats in four generations. The weights in each generation were periodically measured. Total body iron determinations were done on the mothers and on their offspring in fifth generation. Regarding litter size and growth, there was no significant difference between the experimental and control animals in any of the five generations. Although the treated adult females had significantly more total body iron (516-1,129 ppm/g) than the control females (199-248 ppm/g), the difference of total body iron of the offspring of the treated and control females was not statistically significant. Thus it appears that offspring are protected from high body iron that may exist in their mothers.